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GE L90 Instruction Manual

Ur series line current differential system.
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GE
Digital Energy
GE Digital Energy
650 Markland Street
Markham, Ontario
Canada L6C 0M1
Tel: +1 905 927 7070 Fax: +1 905 927 5098
Internet:
http://www.GEDigitalEnergy.com
*1601-0081-Y2*
L90 Line Current Differential
UR Series Instruction Manual
Manual P/N: 1601-0081-Y2 (GEK-113672A)
E83849
LISTED
IND.CONT. EQ.
52TL
System
L90 revision: 7.0x
831776A2.CDR
GE Multilin's Quality Management
System is registered to ISO
9001:2008
QMI # 005094
UL # A3775

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   Summary of Contents for GE L90

  • Page 1 Digital Energy L90 Line Current Differential System UR Series Instruction Manual L90 revision: 7.0x Manual P/N: 1601-0081-Y2 (GEK-113672A) 831776A2.CDR E83849 GE Digital Energy LISTED 650 Markland Street IND.CONT. EQ. 52TL Markham, Ontario GE Multilin's Quality Management Canada L6C 0M1 System is registered to ISO...
  • Page 2 The contents of this manual are the property of GE Multilin Inc. This documentation is furnished on license and may not be reproduced in whole or in part without the permission of GE Multilin. The content of this manual is for informational use only and is subject to change without notice.
  • Page 3: Table Of Contents

    1.3 ENERVISTA UR SETUP SOFTWARE 1.3.1 PC REQUIREMENTS ..................1-5 1.3.2 INSTALLATION....................1-5 1.3.3 CONFIGURING THE L90 FOR SOFTWARE ACCESS........1-6 1.3.4 USING THE QUICK CONNECT FEATURE............1-9 1.3.5 CONNECTING TO THE L90 RELAY ............... 1-15 1.4 UR HARDWARE 1.4.1 MOUNTING AND WIRING................
  • Page 4 INTRODUCTION TO AC SOURCES..............5-5 5.2 PRODUCT SETUP 5.2.1 SECURITY......................5-8 5.2.2 CYBERSENTRY SECURITY................5-12 5.2.3 DISPLAY PROPERTIES ..................5-18 5.2.4 CLEAR RELAY RECORDS ................5-19 5.2.5 COMMUNICATIONS ..................5-20 5.2.6 MODBUS USER MAP ..................5-44 5.2.7 REAL TIME CLOCK ..................5-44 L90 Line Current Differential System GE Multilin...
  • Page 5 OVERFREQUENCY ..................5-249 5.7.8 FREQUENCY RATE OF CHANGE..............5-250 5.7.9 SYNCHROCHECK..................5-252 5.7.10 DIGITAL ELEMENTS..................5-256 5.7.11 DIGITAL COUNTERS ..................5-259 5.7.12 MONITORING ELEMENTS ................5-261 5.7.13 PILOT SCHEMES ..................5-284 5.7.14 AUTORECLOSE .................... 5-308 GE Multilin L90 Line Current Differential System...
  • Page 6 IEC 61580 GOOSE ANALOG VALUES ............6-21 6.3.10 WATTMETRIC GROUND FAULT..............6-22 6.3.11 PHASOR MEASUREMENT UNIT ..............6-22 6.3.12 TRANSDUCER INPUTS AND OUTPUTS ............6-23 6.4 RECORDS 6.4.1 FAULT REPORTS ....................6-24 6.4.2 EVENT RECORDS ...................6-24 6.4.3 OSCILLOGRAPHY ...................6-25 6.4.4 DATA LOGGER ....................6-25 L90 Line Current Differential System GE Multilin...
  • Page 7 9.2 OPERATING CONDITION CHARACTERISTICS 9.2.1 DESCRIPTION....................9-16 9.2.2 TRIP DECISION EXAMPLE................9-18 9.2.3 TRIP DECISION TEST ..................9-18 9.3 DISTANCE ELEMENTS 9.3.1 INTRODUCTION....................9-20 9.3.2 PHASOR ESTIMATION ................... 9-20 9.3.3 DISTANCE CHARACTERISTICS ..............9-21 GE Multilin L90 Line Current Differential System...
  • Page 8 10.7 LINES WITH TAPPED TRANSFORMERS 10.7.1 DESCRIPTION ....................10-24 10.7.2 TRANSFORMER LOAD CURRENTS ............10-24 10.7.3 LV-SIDE FAULTS ...................10-25 10.7.4 EXTERNAL GROUND FAULTS ..............10-25 10.8 INSTANTANEOUS ELEMENTS 10.8.1 INSTANTANEOUS ELEMENT ERROR DURING L90 SYNCHRONIZATION ...10- viii L90 Line Current Differential System GE Multilin...
  • Page 9 C.3 SERVER FEATURES AND CONFIGURATION C.3.1 BUFFERED/UNBUFFERED REPORTING ............C-5 C.3.2 FILE TRANSFER ....................C-5 C.3.3 TIMESTAMPS AND SCANNING ...............C-5 C.3.4 LOGICAL DEVICE NAME..................C-5 C.3.5 LOCATION......................C-5 C.3.6 LOGICAL NODE NAME PREFIXES ..............C-6 C.3.7 CONNECTION TIMING ..................C-6 GE Multilin L90 Line Current Differential System...
  • Page 10 E.2.4 ANALOG INPUTS.................... E-11 F. MISCELLANEOUS F.1 CHANGE NOTES F.1.1 REVISION HISTORY..................F-1 F.1.2 CHANGES TO THE L90 MANUAL ..............F-2 F.2 ABBREVIATIONS F.2.1 STANDARD ABBREVIATIONS ............... F-14 F.3 WARRANTY F.3.1 GE MULTILIN WARRANTY................F-18 L90 Line Current Differential System...
  • Page 11: Getting Started

    1.1 IMPORTANT PROCEDURES 1 GETTING STARTED 1.1IMPORTANT PROCEDURES Read this chapter to help guide you through the initial setup of your new L90 Line Current Differential System. 1.1.1 CAUTIONS AND WARNINGS Before attempting to install or use the device, review all safety indicators in this document to help prevent injury, equipment damage, or downtime.
  • Page 12: Ur Overview

    This new generation of equipment is easily incorporated into automation systems, at both the station and enterprise levels. The GE Multilin Uni- versal Relay (UR) series meets these goals.
  • Page 13: Hardware Architecture

    (dual) ring configuration. This feature is optimized for speed and intended for pilot- aided schemes, distributed logic applications, or the extension of the input/output capabilities of a single relay chassis. GE Multilin L90 Line Current Differential System...
  • Page 14: Software Architecture

    Employing OOD/OOP in the software architecture of the L90 achieves the same features as the hardware architecture: modularity, scalability, and flexibility. The application software for any UR-series device (for example, feeder protection, transformer protection, distance protection) is constructed by combining objects from the various functional classes.
  • Page 15: Enervista Ur Setup Software

    Video capable of displaying 800 x 600 or higher in high-color mode (16-bit color) • RS232 and/or Ethernet port for communications to the relay The following qualified modems have been tested to be compliant with the L90 and the EnerVista UR Setup software: • US Robotics external 56K FaxModem 5686 •...
  • Page 16: Configuring The L90 For Software Access

    OVERVIEW The user can connect remotely to the L90 through the rear RS485 port or the rear Ethernet port with a computer running the EnerVista UR Setup software. The L90 can also be accessed locally with a laptop computer through the front panel RS232 port or the rear Ethernet port using the Quick Connect feature.
  • Page 17 An Ethernet module must be specified at the time of ordering. • To configure the L90 for local access with a laptop through either the front RS232 port or rear Ethernet port, see the Using the Quick Connect Feature section.
  • Page 18 1 GETTING STARTED 10. Click the Read Order Code button to connect to the L90 device and upload the order code. If a communications error occurs, ensure that the EnerVista UR Setup serial communications values entered in the previous step correspond to the relay setting values.
  • Page 19: Using The Quick Connect Feature

    MODBUS PROTOCOL 11. Click the Read Order Code button to connect to the L90 device and upload the order code. If an communications error occurs, ensure that the three EnerVista UR Setup values entered in the previous steps correspond to the relay setting values.
  • Page 20 Now, assign the computer an IP address compatible with the relay’s IP address. From the Windows desktop, right-click the My Network Places icon and select Properties to open the network con- nections window. Right-click the Local Area Connection icon and select Properties. 1-10 L90 Line Current Differential System GE Multilin...
  • Page 21 Select the Internet Protocol (TCP/IP) item from the list, and click the Properties button. Click the “Use the following IP address” box. Enter an IP address with the first three numbers the same as the IP address of the L90 relay and the last number dif- ferent (in this example, 1.1.1.2).
  • Page 22 Minimum = 0ms, Maximum = 0ms, Average = 0 ms Pinging 1.1.1.1 with 32 bytes of data: verify the physical connection between the L90 and the laptop computer, and double-check the programmed IP address in the setting, then repeat step 2.
  • Page 23 Click the Quick Connect button to open the Quick Connect dialog box. Select the Ethernet interface and enter the IP address assigned to the L90, then click the Connect button. The EnerV- ista UR Setup software creates a site named “Quick Connect” with a corresponding device also named “Quick Con- nect”...
  • Page 24 Set the computer to “Obtain a relay address automatically” as shown. If this computer is used to connect to the Internet, re-enable any proxy server settings after the computer has been discon- nected from the L90 relay. AUTOMATIC DISCOVERY OF ETHERNET DEVICES The EnerVista UR Setup software can automatically discover and communicate to all UR-series IEDs located on an Ether- net network.
  • Page 25: Connecting To The L90 Relay

    The EnerVista UR Setup software has several quick action buttons to provide instant access to several functions that are often performed when using L90 relays. From the online window, users can select the relay to interrogate from a pull-down window, then click the button for the action they want to perform. The following quick action functions are available: •...
  • Page 26: Ur Hardware

    This device (catalog number F485) connects to the computer using a straight-through serial cable. A shielded twisted-pair (20, 22, or 24 AWG) connects the F485 converter to the L90 rear communications port. The converter terminals (+, –, GND) are connected to the L90 communication module (+, –, COM) terminals. See the CPU communica- tions ports section in chapter 3 for details.
  • Page 27: Using The Relay

    To put the relay in the “Programmed” state, press either of the VALUE keys once and then press ENTER. The face- plate Trouble LED turns off and the In Service LED turns on. GE Multilin L90 Line Current Differential System 1-17...
  • Page 28: Relay Passwords

    See the Changing Settings section in Chapter 4 for complete instructions on setting security-level passwords. 1.5.6 FLEXLOGIC™ CUSTOMIZATION NOTE FlexLogic equation editing is required for setting user-defined logic for customizing the relay operations. See the FlexLogic section in Chapter 5. 1-18 L90 Line Current Differential System GE Multilin...
  • Page 29: Commissioning

    As such, no further functional tests are required. The L90 performs a number of continual self-tests and takes the necessary action in case of any major errors (see the Relay Self-tests section in chapter 7). However, it is recommended that L90 maintenance be scheduled with other system maintenance.
  • Page 30 1.5 USING THE RELAY 1 GETTING STARTED 1-20 L90 Line Current Differential System GE Multilin...
  • Page 31: Product Description

    Both distance and line differential elements can run simultaneously. The L90 is intended to provide complete protection for transmission lines of any voltage level. Both three phase and single phase tripping schemes are available. Models of the L90 are available for application on both two and three terminal lines.
  • Page 32 Digital Counters (8) Modbus User Map Virtual Inputs (64) Digital Elements (48) Non-Volatile Latches Virtual Outputs (96) Direct Inputs (8 per L90 comms channel) Non-Volatile Selector Switch VT Fuse Failure Disconnect Switches Open Pole Detector DNP 3.0 or IEC 60870-5-104 protocol...
  • Page 33: Features

    Zero-sequence removal for application on lines with tapped transformers connected in a grounded wye on the line side. • GE phaselets approach based on the Discrete Fourier Transform with 64 samples per cycle and transmitting two time- stamped phaselets per cycle. •...
  • Page 34: Ordering

    2.1.3 ORDERING a) OVERVIEW The L90 is available as a 19-inch rack horizontal mount or reduced-size (¾) vertical unit and consists of the following mod- ules: power supply, CPU, CT/VT, digital input and output, transducer input and output, and inter-relay communications.
  • Page 35 RS422, 2 Channels, 2 Clock Inputs RS422, 2 Channels The order codes for the reduced size vertical mount units with traditional CTs and VTs are shown below. Table 2–4: L90 ORDER CODES (REDUCED SIZE VERTICAL UNITS) * - F Reduced Size Vertical Mount...
  • Page 36 RS422, 2 Channels c) ORDER CODES WITH PROCESS BUS MODULES The order codes for the horizontal mount units with the process bus module are shown below. Table 2–5: L90 ORDER CODES (HORIZONTAL UNITS WITH PROCESS BUS) * - F - W/X...
  • Page 37 RS422, 2 Channels The order codes for the reduced size vertical mount units with the process bus module are shown below. Table 2–6: L90 ORDER CODES (REDUCED SIZE VERTICAL UNITS WITH PROCESS BUS) * - F Reduced Size Vertical Mount...
  • Page 38: Replacement Modules

    Replacement modules can be ordered separately. When ordering a replacement CPU module or faceplate, provide the serial number of your existing unit. Not all replacement modules may be applicable to the L90 relay. Only the modules specified in the order codes are available as replacement modules.
  • Page 39 4 dcmA inputs, 4 dcmA outputs (only one 5A module is allowed) 8 RTD inputs INPUTS/OUTPUTS 4 RTD inputs, 4 dcmA outputs (only one 5D module is allowed) 4 dcmA inputs, 4 RTD inputs 8 dcmA inputs GE Multilin L90 Line Current Differential System...
  • Page 40 4 dcmA inputs, 4 dcmA outputs (only one 5A module is allowed) 8 RTD inputs INPUTS/OUTPUTS 4 RTD inputs, 4 dcmA outputs (only one 5D module is allowed) 4 dcmA inputs, 4 RTD inputs 8 dcmA inputs 2-10 L90 Line Current Differential System GE Multilin...
  • Page 41: Pilot Channel Relaying

    (DTT) signal to all of the other L90 relays on the protected line. If a slave L90 relay issues a trip from one of its backup functions, it can send a transfer trip signal to its master and other slave relays if such option is designated.
  • Page 42: Channel Monitor

    2.2.2 CHANNEL MONITOR The L90 has logic to detect that the communications channel is deteriorating or has failed completely. This can provide an alarm indication and disable the current differential protection. Note that a failure of the communications from the master to a slave does not prevent the master from performing the current differential algorithm;...
  • Page 43: Loopback Test

    The L90 includes provision for sending and receiving a single-pole direct transfer trip (DTT) signal from current differential protection between the L90 relays at the line terminals using the pilot communications channel. The user may also initiate an additional eight pilot signals with an L90 communications channel to create trip, block, or signaling logic. A FlexLogic operand, an external contact closure, or a signal over the LAN communication channels can be assigned for that logic.
  • Page 44: Functionality

    Current differential protection: The current differential algorithms used in the L90 Line Current Differential System are based on the Fourier transform phaselet approach and an adaptive statistical restraint. The L90 uses per-phase differential at 64 kbps with two phaselets per cycle. A detailed description of the current differential algorithms is found in chapter 8.
  • Page 45: Other Functions

    PFLL Status Frequency Deviation Phase and Frequency Master Locked Loop (PFLL) Clock Phase Deviation PHASELETS TO REMOTE Communications Remote Relay PHASELETS FROM REMOTE Interface Direct Transfer Trip 831732A3.CDR Figure 2–3: L90 BLOCK DIAGRAM GE Multilin L90 Line Current Differential System 2-15...
  • Page 46: Specifications

    1 to 1.5 cycles (typical) Reset time: 1 power cycle (typical) LINE PICKUP Phase instantaneous overcurrent: 0.000 to 30.000 pu Undervoltage pickup: 0.000 to 3.000 pu Overvoltage delay: 0.000 to 65.535 s 2-16 L90 Line Current Differential System GE Multilin...
  • Page 47 Operate at > 1.03  actual pickup Timing accuracy: Operate at 1.5  pickup Timing accuracy: ±3.5% of operate time or ±½ cycle ±3% or ±4 ms (whichever is greater) (whichever is greater) GE Multilin L90 Line Current Differential System 2-17...
  • Page 48 ±0.5% of reading from 10 to 208 V Pickup delay: 0.00 to 600.00 in steps of 0.01 s 30 ms at 1.10  pickup at 60 Hz Operate time: Timing accuracy: ±3% or ±4 ms (whichever is greater) 2-18 L90 Line Current Differential System GE Multilin...
  • Page 49 ¼ cycle after breaker opens Availability: one per CT/VT module (not including 8Z modules) Pickup level: 0.1 to 2.00 pu in steps of 0.01 Reset delay: 0.000 to 65.535 s in steps of 0.001 GE Multilin L90 Line Current Differential System 2-19...
  • Page 50: User-programmable Elements

    0 to 60000 (ms, sec., min.) in steps of 1 Supported operations: NOT, XOR, OR (2 to 16 inputs), AND (2 to 16 inputs), NOR (2 to 16 inputs), NAND (2 to 16 inputs), latch (reset-domi- nant), edge detectors, timers 2-20 L90 Line Current Differential System GE Multilin...
  • Page 51: Monitoring

    FlexLogic equation put change of state; self-test events Data: AC input channels; element state; digital Data storage: in non-volatile memory input state; digital output state Data storage: in non-volatile memory GE Multilin L90 Line Current Differential System 2-21...
  • Page 52: Metering

    3-Phase Power (P, Q, and S) present WATT-HOURS (POSITIVE AND NEGATIVE) and maximum measured currents Accuracy: ±2.0% of reading Accuracy: ±2.0% ±0 to 1  10 Range: Parameters: three-phase only Update rate: 50 ms 2-22 L90 Line Current Differential System GE Multilin...
  • Page 53: Inputs

    32, configured from 64 incoming bit pairs Debounce time: 0.0 to 16.0 ms in steps of 0.5 Remote devices: Continuous current draw:3 mA (when energized) Default states on loss of comms.: On, Off, Latest/Off, Latest/On Remote DPS inputs: GE Multilin L90 Line Current Differential System 2-23...
  • Page 54: Power Supply

    Operate time: < 0.6 ms FORM-A VOLTAGE MONITOR Internal Limiting Resistor: 100 , 2 W Applicable voltage: approx. 15 to 250 V DC Trickle current: approx. 1 to 2.5 mA 2-24 L90 Line Current Differential System GE Multilin...
  • Page 55 L/R = 20 ms L/R = 40 ms L/R = 40 ms Upper and lower limit for the driving signal: –90 to 90 pu in steps of 0.8 A L/R = 40 ms 0.001 GE Multilin L90 Line Current Differential System 2-25...
  • Page 56: Communications

    –30 dBm 29 dB Singlemode 1550 nm Laser, +5 dBm –30 dBm 35 dB Singlemode These power budgets are calculated from the manu- facturer’s worst-case transmitter power and worst NOTE case receiver sensitivity. 2-26 L90 Line Current Differential System GE Multilin...
  • Page 57: Environmental

    Pollution degree: impaired at temperatures less than – Overvoltage category: 20°C Ingress protection: IP20 front, IP10 back HUMIDITY Humidity: operating up to 95% (non-condensing) at 55°C (as per IEC60068-2-30 variant 1, 6 days). GE Multilin L90 Line Current Differential System 2-27...
  • Page 58: Type Tests

    Safety UL508 e83849 NKCR Safety UL C22.2-14 e83849 NKCR7 Safety UL1053 e83849 NKCR 2.4.12 PRODUCTION TESTS THERMAL Products go through an environmental test based upon an Accepted Quality Level (AQL) sampling process. 2-28 L90 Line Current Differential System GE Multilin...
  • Page 59: Approvals

    To avoid deterioration of electrolytic capacitors, power up units that are stored in a de-energized state once per year, for one hour continuously. GE Multilin L90 Line Current Differential System 2-29...
  • Page 60 2.4 SPECIFICATIONS 2 PRODUCT DESCRIPTION 2-30 L90 Line Current Differential System GE Multilin...
  • Page 61: Hardware

    HORIZONTAL UNITS The L90 Line Current Differential System is available as a 19-inch rack horizontal mount unit with a removable faceplate. The faceplate can be specified as either standard or enhanced at the time of ordering. The enhanced faceplate contains additional user-programmable pushbuttons and LED indicators.
  • Page 62 VERTICAL UNITS The L90 Line Current Differential System is available as a reduced size (¾) vertical mount unit, with a removable faceplate. The faceplate can be specified as either standard or enhanced at the time of ordering. The enhanced faceplate contains additional user-programmable pushbuttons and LED indicators.
  • Page 63 RS232 communications port. The relay is secured to the panel with the use of four screws supplied with the relay. 11.015” 7.482” 1.329” 13.560” 15.000” 14.025” 4.000” 9.780” 843809A1.CDR Figure 3–4: L90 VERTICAL DIMENSIONS (ENHANCED PANEL) GE Multilin L90 Line Current Differential System...
  • Page 64 3.1 DESCRIPTION 3 HARDWARE Figure 3–5: L90 VERTICAL MOUNTING AND DIMENSIONS (STANDARD PANEL) For details on side mounting L90 devices with the enhanced front panel, refer to the following documents available online from the GE Multilin website. • GEK-113180: UR-series UR-V side-mounting front panel assembly instructions.
  • Page 65 3 HARDWARE 3.1 DESCRIPTION Figure 3–6: L90 VERTICAL SIDE MOUNTING INSTALLATION (STANDARD PANEL) GE Multilin L90 Line Current Differential System...
  • Page 66: Module Withdrawal And Insertion

    The enhanced faceplate can be opened to the left, once the thumb screw has been removed, as shown below. This allows for easy accessibility of the modules for withdrawal. The new wide-angle hinge assembly in the enhanced front panel opens completely and allows easy access to all modules in the L90. L90 Line Current Differential System...
  • Page 67 The new CT/VT modules can only be used with new CPUs; similarly, old CT/VT modules can only be used with old CPUs. In the event that there is a mismatch between the CPU and CT/VT module, the relay does not function and error displays. NOTE DSP ERROR HARDWARE MISMATCH GE Multilin L90 Line Current Differential System...
  • Page 68: Rear Terminal Layout

    (nearest to CPU module) which is indicated by an arrow marker on the terminal block. See the following figure for an example of rear terminal assignments. Figure 3–11: EXAMPLE OF MODULES IN F AND H SLOTS L90 Line Current Differential System GE Multilin...
  • Page 69: Wiring

    3 HARDWARE 3.2 WIRING 3.2WIRING 3.2.1 TYPICAL WIRING Figure 3–12: TYPICAL WIRING DIAGRAM GE Multilin L90 Line Current Differential System...
  • Page 70: Dielectric Strength

    (see the Self-test errors section in chapter 7) or control power is lost, the relay is de-energize. For high reliability systems, the L90 has a redundant option in which two L90 power supplies are placed in parallel on the bus.
  • Page 71: Ct/vt Modules

    CT connections for both ABC and ACB phase rotations are identical as shown in the Typical wiring diagram. The exact placement of a zero-sequence core balance CT to detect ground fault current is shown below. Twisted-pair cabling on the zero-sequence CT is recommended. GE Multilin L90 Line Current Differential System 3-11...
  • Page 72 NOTE Current inputs Voltage inputs 8F, 8G, 8L, and 8M modules (4 CTs and 4 VTs) Current inputs 8H, 8J, 8N, and 8R modules (8 CTs) 842766A3.CDR Figure 3–15: CT/VT MODULE WIRING 3-12 L90 Line Current Differential System GE Multilin...
  • Page 73: Process Bus Modules

    3.2.5 PROCESS BUS MODULES The L90 can be ordered with a process bus interface module. This module is designed to interface with the GE Multilin HardFiber system, allowing bidirectional IEC 61850 fiber optic communications with up to eight HardFiber merging units, known as Bricks.
  • Page 74 Logic operand driving the contact output should be given a reset delay of 10 ms to prevent damage of the output contact (in situations when the element initiating the contact output is bouncing, at val- ues in the region of the pickup value). 3-14 L90 Line Current Differential System GE Multilin...
  • Page 75 ~7a, ~7c 2 Inputs ~7a, ~7c 2 Inputs ~7a, ~7c 2 Inputs ~7a, ~7c 2 Inputs ~8a, ~8c 2 Inputs ~8a, ~8c 2 Inputs ~8a, ~8c 2 Inputs ~8a, ~8c 2 Inputs GE Multilin L90 Line Current Differential System 3-15...
  • Page 76 ~5a, ~5c 2 Inputs 2 Outputs Solid-State Solid-State ~6a, ~6c 2 Inputs 2 Outputs Not Used Not Used ~7a, ~7c 2 Inputs 2 Outputs Solid-State Solid-State ~8a, ~8c 2 Inputs Not Used 3-16 L90 Line Current Differential System GE Multilin...
  • Page 77 3 HARDWARE 3.2 WIRING Figure 3–17: CONTACT INPUT AND OUTPUT MODULE WIRING (1 of 2) GE Multilin L90 Line Current Differential System 3-17...
  • Page 78 CONTACT IN COMMON SURGE 842763A2.CDR Figure 3–18: CONTACT INPUT AND OUTPUT MODULE WIRING (2 of 2) For proper functionality, observe correct polarity for all contact input and solid state output connec- tions. 3-18 L90 Line Current Differential System GE Multilin...
  • Page 79 There is no provision in the relay to detect a DC ground fault on 48 V DC control power external output. We recom- mend using an external DC supply. NOTE GE Multilin L90 Line Current Differential System 3-19...
  • Page 80 CONTACT INPUT 2 AUTO-BURNISH = ON 842751A1.CDR Figure 3–21: AUTO-BURNISH DIP SWITCHES The auto-burnish circuitry has an internal fuse for safety purposes. During regular maintenance, check the auto- burnish functionality using an oscilloscope. NOTE 3-20 L90 Line Current Differential System GE Multilin...
  • Page 81: Transducer Inputs And Outputs

    (5A, 5C, 5D, 5E, and 5F) and channel arrangements that can be ordered for the relay. Wherever a tilde “~” symbol appears, substitute with the slot position of the module. NOTE Figure 3–22: TRANSDUCER INPUT/OUTPUT MODULE WIRING GE Multilin L90 Line Current Differential System 3-21...
  • Page 82: Rs232 Faceplate Port

    3.2.8 RS232 FACEPLATE PORT A 9-pin RS232C serial port is located on the L90 faceplate for programming with a computer. All that is required to use this interface is a computer running the EnerVista UR Setup software provided with the relay. Cabling for the RS232 port is shown in the following figure for both 9-pin and 25-pin connectors.
  • Page 83 This common voltage is implied to be a power supply common. Some systems allow the shield (drain wire) to be used as common wire and to connect directly to the L90 COM terminal (#3); others function cor- rectly only if the common wire is connected to the L90 COM terminal, but insulated from the shield.
  • Page 84: Irig-b

    Using an amplitude modulated receiver causes errors up to 1 ms in event time-stamping. NOTE Using an amplitude modulated receiver also causes errors of up to 1 ms in metered synchrophasor values. NOTE 3-24 L90 Line Current Differential System GE Multilin...
  • Page 85: Pilot Channel Communications

    RS422, 1 channel RS422, 2 channels, 2 clock inputs RS422, 2 channels All of the fiber modules use ST type connectors. For two-terminal applications, each L90 relay requires at least one com- munications channel. GE Multilin L90 Line Current Differential System...
  • Page 86: Fiber: Led And Eled Transmitters

    The following figure shows the configuration for the 72, 73, 7D, and 7K fiber-laser module. Figure 3–28: LASER FIBER MODULES When using a laser Interface, attenuators can be necessary to ensure that you do not exceed the maximum optical input power to the receiver. 3-26 L90 Line Current Differential System GE Multilin...
  • Page 87: Interface

    Remove the top cover by sliding it towards the rear and then lift it upwards. Set the timing selection switches (channel 1, channel 2) to the desired timing modes. Replace the top cover and the cover screw. GE Multilin L90 Line Current Differential System 3-27...
  • Page 88 For connection to a higher order system (UR- to-multiplexer, factory defaults), set to octet timing (S1 = ON) and set timing mode to loop timing (S5 = OFF and S6 = OFF). 3-28 L90 Line Current Differential System GE Multilin...
  • Page 89 G.703 line side of the interface while the other lies on the differential Manchester side of the interface. DMR = Differential Manchester Receiver DMX = Differential Manchester Transmitter G7X = G.703 Transmitter G7R = G.703 Receiver 842775A1.CDR Figure 3–33: G.703 DUAL LOOPBACK MODE GE Multilin L90 Line Current Differential System 3-29...
  • Page 90: Rs422 Interface

    (data module 1), connects to the clock inputs of the UR–RS422 interface in the usual fashion. In addition, the send timing outputs of data module 1 is also paralleled to the terminal timing inputs of data module 2. By using this con- 3-30 L90 Line Current Differential System GE Multilin...
  • Page 91 Figure 3–36: TIMING CONFIGURATION FOR RS422 TWO-CHANNEL, 3-TERMINAL APPLICATION Data module 1 provides timing to the L90 RS422 interface via the ST(A) and ST(B) outputs. Data module 1 also provides timing to data module 2 TT(A) and TT(B) inputs via the ST(A) and AT(B) outputs. The data module pin numbers have been omitted in the figure above since they vary by manufacturer.
  • Page 92: Two-channel Two-clock Rs422 Interface

    When using a LASER Interface, attenuators can be necessary to ensure that you do not exceed maximum optical input power to the receiver. Figure 3–39: RS422 AND FIBER INTERFACE CONNECTION Connections shown above are for multiplexers configured as DCE (data communications equipment) units. 3-32 L90 Line Current Differential System GE Multilin...
  • Page 93: And Fiber Interface

    Connection: as per all fiber optic connections, a Tx to Rx connection is required The UR-series C37.94 communication module can be connected directly to any compliant digital multiplexer that supports the IEEE C37.94 standard as shown below. GE Multilin L90 Line Current Differential System 3-33...
  • Page 94 Once the clips have cleared the raised edge of the chassis, engage the clips simultaneously. When the clips have locked into position, the module is fully inserted. 3-34 L90 Line Current Differential System GE Multilin...
  • Page 95 3 HARDWARE 3.3 PILOT CHANNEL COMMUNICATIONS Figure 3–41: IEEE C37.94 TIMING SELECTION SWITCH SETTING GE Multilin L90 Line Current Differential System 3-35...
  • Page 96 Solid yellow — FPGA is receiving a "yellow bit" and remains yellow for each "yellow bit" • Solid red — FPGA is not receiving a valid packet or the packet received is invalid 3-36 L90 Line Current Differential System GE Multilin...
  • Page 97: C37.94sm Interface

    For the internal timing mode, the system clock is generated internally. Therefore, the timing switch selection should be internal timing for relay 1 and loop timed for relay 2. There must be only one timing source configured. GE Multilin L90 Line Current Differential System 3-37...
  • Page 98 Once the clips have cleared the raised edge of the chassis, engage the clips simultaneously. When the clips have locked into position, the module is fully inserted. Figure 3–43: C37.94SM TIMING SELECTION SWITCH SETTING 3-38 L90 Line Current Differential System GE Multilin...
  • Page 99 Solid yellow — FPGA is receiving a "yellow bit" and remains yellow for each "yellow bit" • Solid red — FPGA is not receiving a valid packet or the packet received is invalid GE Multilin L90 Line Current Differential System 3-39...
  • Page 100 3.3 PILOT CHANNEL COMMUNICATIONS 3 HARDWARE 3-40 L90 Line Current Differential System GE Multilin...
  • Page 101: Human Interfaces

    ENGAGING A DEVICE The EnerVista UR Setup software can be used in online mode (relay connected) to directly communicate with the L90 relay. Communicating relays are organized and grouped by communication interfaces and into sites. Sites can contain any num- ber of relays selected from the UR-series of relays.
  • Page 102 Site List window are automatically sent to the online communicating device. g) FIRMWARE UPGRADES The firmware of a L90 device can be upgraded, locally or remotely, via the EnerVista UR Setup software. The correspond- ing instructions are provided by the EnerVista UR Setup Help file under the topic “Upgrading Firmware”.
  • Page 103 EEPROM DATA ERROR message intended to inform users that the Modbus addresses have changed with the upgraded firmware. This message does not signal any problems when appearing after firmware upgrades. GE Multilin L90 Line Current Differential System...
  • Page 104: Enervista Ur Setup Main Window

    Device data view windows, with common tool bar Settings file data view windows, with common tool bar Workspace area with data view tabs Status bar 10. Quick action hot links 842786A2.CDR Figure 4–1: ENERVISTA UR SETUP SOFTWARE MAIN WINDOW L90 Line Current Differential System GE Multilin...
  • Page 105: Extended Enervista Ur Setup Features

    Select the Template Mode > Edit Template option to place the device in template editing mode. Enter the template password then click OK. Open the relevant settings windows that contain settings to be specified as viewable. GE Multilin L90 Line Current Differential System...
  • Page 106 The following procedure describes how to add password protection to a settings file template. Select a settings file from the offline window on the left of the EnerVista UR Setup main screen. Selecting the Template Mode > Password Protect Template option. L90 Line Current Differential System GE Multilin...
  • Page 107 Template Mode > View In Template Mode command. The template specifies that only the Pickup Curve Phase time overcurrent settings window without template applied. settings be available. 842858A1.CDR Figure 4–4: APPLYING TEMPLATES VIA THE VIEW IN TEMPLATE MODE COMMAND GE Multilin L90 Line Current Differential System...
  • Page 108 Select an installed device or settings file from the tree menu on the left of the EnerVista UR Setup main screen. Select the Template Mode > Remove Settings Template option. Enter the template password and click OK to continue. L90 Line Current Differential System GE Multilin...
  • Page 109: Securing And Locking Flexlogic™ Equations

    Click on Save to save and apply changes to the settings template. Select the Template Mode > View In Template Mode option to view the template. Apply a password to the template then click OK to secure the FlexLogic equation. GE Multilin L90 Line Current Differential System...
  • Page 110 FlexLogic entries in a settings file have been secured, use the following procedure to lock the settings file to a specific serial number. Select the settings file in the offline window. Right-click on the file and select the Edit Settings File Properties item. 4-10 L90 Line Current Differential System GE Multilin...
  • Page 111: Settings File Traceability

    When a settings file is transferred to a L90 device, the date, time, and serial number of the L90 are sent back to EnerVista UR Setup and added to the settings file on the local PC. This infor- mation can be compared with the L90 actual values at any later date to determine if security has been compromised.
  • Page 112 4 HUMAN INTERFACES The transfer date of a setting file written to a L90 is logged in the relay and can be viewed via EnerVista UR Setup or the front panel display. Likewise, the transfer date of a setting file saved to a local PC is logged in EnerVista UR Setup.
  • Page 113 ONLINE DEVICE TRACEABILITY INFORMATION The L90 serial number and file transfer date are available for an online device through the actual values. Select the Actual Values > Product Info > Model Information menu item within the EnerVista UR Setup online window as shown in the example below.
  • Page 114: Faceplate Interface

    LED panel 2 LED panel 3 Display Front panel RS232 port Small user-programmable User-programmable Keypad (control) pushbuttons 1 to 7 pushbuttons 1 to 12 827801A7.CDR Figure 4–16: UR-SERIES STANDARD HORIZONTAL FACEPLATE PANELS 4-14 L90 Line Current Differential System GE Multilin...
  • Page 115: Led Indicators

    The status indicators in the first column are described below. • IN SERVICE: This LED indicates that control power is applied, all monitored inputs, outputs, and internal systems are OK, and that the device has been programmed. GE Multilin L90 Line Current Differential System 4-15...
  • Page 116 Support for applying a customized label beside every LED is provided. Default labels are shipped in the label pack- age of every L90, together with custom templates. The default labels can be replaced by user-printed labels. User customization of LED operation is of maximum benefit in installations where languages other than English are used to communicate with operators.
  • Page 117 LEDs on these panels. USER-PROGRAMMABLE LEDS USER-PROGRAMMABLE LEDS 842782A1.CDR Figure 4–20: LED PANELS 2 AND 3 (INDEX TEMPLATE) DEFAULT LABELS FOR LED PANEL 2: The default labels are intended to represent: GE Multilin L90 Line Current Differential System 4-17...
  • Page 118: Custom Labeling Of Leds

    EnerVista UR Setup software is installed and operational • The L90 settings have been saved to a settings file • The L90 front panel label cutout sheet (GE Multilin part number 1006-0047) has been downloaded from http:// www.gedigitalenergy.com/products/support/ur/URLEDenhanced.doc and printed •...
  • Page 119 Enter the text to appear next to each LED and above each user-programmable pushbuttons in the fields provided. Feed the L90 front panel label cutout sheet into a printer and press the Print button in the front panel report window.
  • Page 120 4 HUMAN INTERFACES Bend the tab at the center of the tool tail as shown below. The following procedure describes how to remove the LED labels from the L90 enhanced front panel and insert the custom labels. Use the knife to lift the LED label and slide the label tool underneath. Make sure the bent tabs are pointing away from the relay.
  • Page 121 Slide the new LED label inside the pocket until the text is properly aligned with the LEDs, as shown below. The following procedure describes how to remove the user-programmable pushbutton labels from the L90 enhanced front panel and insert the custom labels.
  • Page 122 Slide the label tool under the user-programmable pushbutton label until the tabs snap out as shown below. This attaches the label tool to the user-programmable pushbutton label. Remove the tool and attached user-programmable pushbutton label as shown below. 4-22 L90 Line Current Differential System GE Multilin...
  • Page 123 The panel templates provide relative LED locations and located example text (x) edit boxes. The following procedure demonstrates how to install/uninstall the custom panel labeling. Remove the clear Lexan Front Cover (GE Multilin part number: 1501-0014). Push in...
  • Page 124: Display

    INTRODUCTION The L90 can interface with associated circuit breakers. In many cases the application monitors the state of the breaker, that can be presented on faceplate LEDs, along with a breaker trouble indication. Breaker operations can be manually initiated from faceplate keypad or automatically initiated from a FlexLogic operand.
  • Page 125: Menus

    Each press of the MENU key advances through the following main heading pages: • Actual values • Settings • Commands • Targets • User displays (when enabled) GE Multilin L90 Line Current Differential System 4-25...
  • Page 126 Properties. TIME: 1.0 s  To view the remaining settings associated with the Display Properties subheader, DEFAULT MESSAGE repeatedly press the MESSAGE DOWN key. The last message appears as shown. INTENSITY: 25% 4-26 L90 Line Current Differential System GE Multilin...
  • Page 127: Changing Settings

    ENTERING ALPHANUMERIC TEXT Text settings have data values which are fixed in length, but user-defined in character. They can be upper case letters, lower case letters, numerals, and a selection of special characters. GE Multilin L90 Line Current Differential System 4-27...
  • Page 128: Settings

    When the "NEW SETTING HAS BEEN STORED" message appears, the relay is in "Programmed" state and the In Service LED turns on. e) ENTERING INITIAL PASSWORDS The L90 supports password entry from a local or remote connection. 4-28 L90 Line Current Differential System...
  • Page 129 When an incorrect command or setting password has been entered via the faceplate interface three times within a 3-minute time span, the FlexLogic operand is set to “On” and the L90 does not allow settings or command LOCAL ACCESS DENIED...
  • Page 130 FlexLogic operand is set to “On” and the REMOTE ACCESS DENIED L90 does not allow Settings or Command access via the any external communications interface for the next ten minutes. FlexLogic operand is set to “Off” after the expiration of the ten-minute timeout.
  • Page 131: Overview

     SETTINGS  AC INPUTS See page 5-73.  SYSTEM SETUP   POWER SYSTEM See page 5-74.   SIGNAL SOURCES See page 5-75.   L90 POWER SYSTEM See page 5-78.  GE Multilin L90 Line Current Differential System...
  • Page 132  UNDERFREQUENCY See page 5-248.   OVERFREQUENCY See page 5-249.   FREQUENCY RATE See page 5-250.  OF CHANGE  SYNCHROCHECK See page 5-252.   DIGITAL ELEMENTS See page 5-256.  L90 Line Current Differential System GE Multilin...
  • Page 133  TRANSDUCER I/O   RTD INPUTS See page 5-335.   DCMA OUTPUTS See page 5-337.   SETTINGS TEST MODE See page 5-340.  TESTING FUNCTION: Disabled TEST MODE FORCING: See page 5-340. GE Multilin L90 Line Current Differential System...
  • Page 134: Introduction To Elements

    FUNCTION setting: This setting programs the element to be operational when selected as “Enabled”. The factory default is “Disabled”. Once programmed to “Enabled”, any element associated with the function becomes active and all options become available. • NAME setting: This setting is used to uniquely identify the element. L90 Line Current Differential System GE Multilin...
  • Page 135: Introduction To Ac Sources

    Sources, in the context of L90 series relays, refer to the logical grouping of current and voltage signals such that one source contains all the signals required to measure the load or fault in a particular power apparatus. A given source may contain all or some of the following signals: three-phase currents, single-phase ground current, three-phase voltages and an auxiliary voltages from a single-phase VT for checking for synchronism.
  • Page 136 CTs through which any portion of the current for the element being protected could flow. Auxiliary CTs are required to perform ratio matching if the ratios of the primary CTs to be summed are not identical. In the L90 relay, provisions have been included for all the current signals to be brought to the device where grouping, CT ratio correction, and summation are applied internally via configuration settings.
  • Page 137 CTs on each of two breakers is required to measure the winding current flow. GE Multilin L90 Line Current Differential System...
  • Page 138: Product Setup

    When entering a settings or command password via EnerVista or any serial interface, the user must enter the correspond- ing connection password. If the connection is to the back of the L90, the remote password must be used. If the connection is to the RS232 port of the faceplate, the local password must be used.
  • Page 139 ENCRYPTED PASSWORD If the setting and command passwords are identical, then this one password allows access to both commands and settings. NOTE If a remote connection is established, local passcodes are not visible. NOTE GE Multilin L90 Line Current Differential System...
  • Page 140  SUPERVISION  TIMEOUTS Range: 2 to 5 in steps of 1 INVALID ATTEMPTS MESSAGE BEFORE LOCKOUT: 3 Range: 5 to 60 minutes in steps of 1 PASSWORD LOCKOUT MESSAGE DURATION: 5 min 5-10 L90 Line Current Differential System GE Multilin...
  • Page 141 INVALID ATTEMPTS BEFORE LOCKOUT The L90 provides a means to raise an alarm upon failed password entry. Should password verification fail while accessing a password-protected level of the relay (either settings or commands), the FlexLogic operand is UNAUTHORIZED ACCESS asserted.
  • Page 142: Cybersentry Security

    Log in as outlined (Administrator or Supervisor, then Observer). Users After making any required changes, log off using the Commands > Relay Maintenance > Security menu. logged in through the front panel log out by logging in as None. 5-12 L90 Line Current Differential System GE Multilin...
  • Page 143 Whenever a new role is logged in, the user is prompted with a display to enter a password. 20 alphanumeric characters are acceptable as passwords.The UR device supports five roles. All roles have their corresponding passwords. The Observer role is the only role that does not require a password. GE Multilin L90 Line Current Differential System 5-13...
  • Page 144 PRODUCT SETUP SECURITY SESSION SETTINGS Range: 0 to 99  SESSION SESSION LOCKOUT:  SETTINGS Range: 0 to 9999 minutes SESSION LOCKOUT MESSAGE PERIOD: 3 min The following session settings are available. 5-14 L90 Line Current Differential System GE Multilin...
  • Page 145 Range: Enable, Disable FACTORY SERVICE: MESSAGE MODE: Disable  SELF TESTS See below MESSAGE  Range: Enable, Disable SUPERVISOR ROLE: MESSAGE Disable Range: 1 to 9999 minutes SERIAL INACTIVITY MESSAGE TIMEOUT: 3 GE Multilin L90 Line Current Differential System 5-15...
  • Page 146 Example: If this setting is "Yes" and an attempt is made to change settings or upgrade the firmware, the UR device denies the setting changes and denies upgrading the firmware. If this setting is "No", the UR device accepts setting changes and firmware upgrade. This role is disabled by default. 5-16 L90 Line Current Differential System GE Multilin...
  • Page 147 Settings Lock: If this setting is Enabled then an unauthorized write attempt to a setting for a given role activates this self test.      PATH: SETTINGS PRODUCT SETUP SECURITY SUPERVISORY SELF TESTS FAILED AUTHENTICATE Range: Enabled, Disabled  FAILED FAILED AUTHENTICATE  AUTHENTICATE FUNCTION: Enabled GE Multilin L90 Line Current Differential System 5-17...
  • Page 148: Display Properties

    Some customers prefer very low currents to display as zero, while others prefer the current be displayed even when the value reflects noise rather than the actual signal. The L90 applies a cut- off value to the magnitudes and angles of the measured currents.
  • Page 149: Clear Relay Records

    CLEAR EVENT RECORDS: MESSAGE Range: FlexLogic operand CLEAR OSCILLOGRAPHY? MESSAGE Range: FlexLogic operand CLEAR DATA LOGGER: MESSAGE Range: FlexLogic operand CLEAR ARC AMPS 1: MESSAGE Range: FlexLogic operand CLEAR ARC AMPS 2: MESSAGE GE Multilin L90 Line Current Differential System 5-19...
  • Page 150: Communications

    Selected records can be cleared from user-programmable conditions with FlexLogic operands. Assigning user-programma- ble pushbuttons to clear specific records are typical applications for these commands. Since the L90 responds to rising edges of the configured FlexLogic operands, they must be asserted for at least 50 ms to take effect.
  • Page 151 0 ms The L90 is equipped with up to two independent serial communication ports. The faceplate RS232 port is intended for local use and is fixed at 19200 baud and no parity. The rear COM2 port is RS485. The RS485 port has settings for baud rate and parity.
  • Page 152 SCADA is provided through LAN2 and LAN3, to which P2 and respectively P3 are connected and configured to work in redundant mode. In this configuration, P3 uses the IP and MAC address of P2. Figure 5–5: MULTIPLE LANS, WITH REDUNDANCY 5-22 L90 Line Current Differential System GE Multilin...
  • Page 153 Range: Standard IPV4 address format PRT2 SUBNET IP MASK: MESSAGE 0.0.0.0 Range: Standard IPV4 address format PRT2 GWY IP ADDRESS: MESSAGE 0.0.0.0 Range: No, Yes PRT2 REDUNDANCY: MESSAGE Range: Enabled, Disabled PRT2 GOOSE ENABLED: MESSAGE Enabled GE Multilin L90 Line Current Differential System 5-23...
  • Page 154 MODBUS SLAVE ADDRESS grammed. For the RS485 port, each L90 must have a unique address from 1 to 254. Address 0 is the broadcast address which all Modbus slave devices listen to. Addresses do not have to be sequential, but no two devices can have the same address or conflicts resulting in errors will occur.
  • Page 155 DEADBAND: 30000 Range: 0 to 100000000 in steps of 1 DNP OTHER DEFAULT MESSAGE DEADBAND: 30000 Range: 1 to 10080 min. in steps of 1 DNP TIME SYNC IIN MESSAGE PERIOD: 1440 min GE Multilin L90 Line Current Differential System 5-25...
  • Page 156 TIMEOUT: 120 s The L90 supports the Distributed Network Protocol (DNP) version 3.0. The L90 can be used as a DNP slave device con- nected to multiple DNP masters (usually an RTU or a SCADA master station). Since the L90 maintains two sets of DNP data change buffers and connection information, two DNP masters can actively communicate with the L90 at one time.
  • Page 157 DNP analog input points that are voltages will be returned with values 1000 times smaller (for example, a value of 72000 V on the L90 will be returned as 72). These settings are useful when analog input values must be adjusted to fit within cer- tain ranges in DNP masters.
  • Page 158 0 to 32 binary output paired controls. Points not configured as paired operate on POINTS a one-to-one basis. setting is the DNP slave address. This number identifies the L90 on a DNP communications link. Each DNP ADDRESS DNP slave should be assigned a unique address.
  • Page 159 The L90 supports the Manufacturing Message Specification (MMS) protocol as specified by IEC 61850. MMS is supported over two protocol stacks: TCP/IP over ethernet and TP4/CLNP (OSI) over ethernet. The L90 operates as an IEC 61850 server. The Remote inputs and outputs section in this chapter describe the peer-to-peer GSSE/GOOSE message scheme.
  • Page 160 IEC 61850 GSSE application ID name string sent as part of each GSSE message. This GSSE ID string identifies the GSSE message to the receiving device. In L90 releases previous to 5.0x, this name string was repre- sented by the setting.
  • Page 161 DESTINATION MAC address; the least significant bit of the first byte must be set. In L90 releases previous to 5.0x, the destination Ethernet MAC address was determined automatically by taking the sending MAC address (that is, the unique, local MAC address of the L90) and setting the multicast bit.
  • Page 162 The L90 has the ability of detecting if a data item in one of the GOOSE datasets is erroneously oscillating. This can be caused by events such as errors in logic programming, inputs improperly being asserted and de-asserted, or failed station components.
  • Page 163 Configure the transmission dataset. Configure the GOOSE service settings. Configure the data. The general steps required for reception configuration are: Configure the reception dataset. Configure the GOOSE service settings. Configure the data. GE Multilin L90 Line Current Differential System 5-33...
  • Page 164 MMXU1 HZ DEADBAND change greater than 45 mHz, from the previous MMXU1.MX.mag.f value, in the source frequency. The L90 must be rebooted (control power removed and re-applied) before these settings take effect. The following procedure illustrates the reception configuration. Configure the reception dataset by making the following changes in the ...
  • Page 165 IEC61850 GOOSE ANALOG INPUT 1 UNITS The GOOSE analog input 1 can now be used as a FlexAnalog value in a FlexElement or in other settings. The L90 must be rebooted (control power removed and re-applied) before these settings take effect.
  • Page 166 DNA and UserSt bit pairs that are included in GSSE messages. To set up a L90 to receive a configurable GOOSE dataset that contains two IEC 61850 single point status indications, the following dataset items can be selected (for example, for configurable GOOSE dataset 1): “GGIO3.ST.Ind1.stVal” and “GGIO3.ST.Ind2.stVal”.
  • Page 167 CPU resources. When server scanning is disabled, there will be not updated to the IEC 61850 logical node sta- tus values in the L90. Clients will still be able to connect to the server (L90 relay), but most data values will not be updated.
  • Page 168 The GGIO2 control configuration settings are used to set the control model for each input. The available choices are “0” (status only), “1” (direct control), and “2” (SBO with normal security). The GGIO2 control points are used to control the L90 virtual inputs.
  • Page 169 GGIO4. When this value is NUMBER OF ANALOG POINTS changed, the L90 must be rebooted in order to allow the GGIO4 logical node to be re-instantiated and contain the newly configured number of analog points.
  • Page 170 ITEM 64 attributes supported by the L90. Changes to the dataset will only take effect when the L90 is restarted. It is recommended to use reporting service from logical node LLN0 if a user needs some (but not all) data from already existing GGIO1, GGIO4, and MMXU4 points and their quantity is not greater than 64 minus the number items in this dataset.
  • Page 171 XCBR operating counter status attribute (OpCnt) increments with every operation. Frequent breaker operation may result in very large OpCnt values over time. This setting allows the OpCnt to be reset to “0” for XCBR1. GE Multilin L90 Line Current Differential System 5-41...
  • Page 172 Explorer or Firefox. This feature is available when the L90 has the Ethernet option installed. The web pages are organized as a series of menus that can be accessed starting at the L90 “Main Menu”. Web pages are available showing DNP and IEC 60870-5-104 points lists, Modbus registers, event records, fault reports, and so on.
  • Page 173 5.2 PRODUCT SETUP The Trivial File Transfer Protocol (TFTP) can be used to transfer files from the L90 over a network. The L90 operates as a TFTP server. TFTP client software is available from various sources, including Microsoft Windows NT. The dir.txt file obtained from the L90 contains a list and description of all available files (event records, oscillography, etc.).
  • Page 174: Modbus User Map

    Precision Time Protocol (PTP), IRIG-B, or SNTP, its accuracy approaches that of the synchroniz- ing time delivered to the relay. When the L30/L90 channel asymmetry function is used, the relay’s real time clock must be synchronized to an external time source using PTP or IRIG-B, typically from a global positioning system (GPS) receiver.
  • Page 175 Precision Time Protocol (PTP), IRIG-B, or SNTP, its accuracy approaches that of the synchroniz- ing time delivered to the relay. When the L30/L90 channel asymmetry function is used, the relay’s real time clock must be synchronized to an external time source using PTP or IRIG-B, typically from a global positioning system (GPS) receiver.
  • Page 176 PP, the associated propagation delay and/or latency may not be compensated for, and the time received at the end-device could be in error by more than 100 µs. 5-46 L90 Line Current Differential System GE Multilin...
  • Page 177 Depending on the characteristics of the device to which the relay is directly linked, VLAN Priority may have no effect. • This setting applies to all of the relay’s PTP capable ports. GE Multilin L90 Line Current Differential System 5-47...
  • Page 178 GPS receiver to provide an accurate time. Both unicast and broadcast SNTP are supported. If SNTP functionality is enabled at the same time as IRIG-B, the IRIG-B signal provides the time value to the L90 clock for as long as a valid signal is present.
  • Page 179 DAYLIGHT SAVINGS TIME (DST) Note that when IRIG-B time synchronization is active, the local time in the IRIG-B signal contains any daylight savings time offset and so the DST settings are ignored. GE Multilin L90 Line Current Differential System 5-49...
  • Page 180: Fault Reports

    MESSAGE Z0 ANGLE: 75° The L90 incorporates a multi-ended fault locator method based on the synchronized voltage and current measurements at all ends of the transmission line. This makes it possible to compute the fault location without assumptions or approxima- tions.
  • Page 181 When the single-ended algorithm is used for three-terminal line applications, the faulted segment of the line is not deter- mined and reported. The L90 relay supports one fault report and an associated fault locator. The signal source and trigger condition, as well as the characteristics of the line or feeder, are entered in this menu.
  • Page 182 TRIGGER POSITION: MESSAGE Range: FlexLogic operand TRIGGER SOURCE: MESSAGE Range: Off; 8, 16, 32, 64 samples/cycle AC INPUT WAVEFORMS: MESSAGE 16 samples/cycle  DIGITAL CHANNELS MESSAGE   ANALOG CHANNELS MESSAGE  5-52 L90 Line Current Differential System GE Multilin...
  • Page 183 FlexLogic operand state recorded in an oscillography trace. The length of each DIGITAL 1(63) CHANNEL oscillography trace depends in part on the number of parameters selected here. Parameters set to “Off” are ignored. Upon startup, the relay will automatically prepare the parameter list. GE Multilin L90 Line Current Differential System 5-53...
  • Page 184 IB signal on terminal 2 of the CT/VT module in slot F. If there are no CT/VT modules and analog input modules, no analog traces will appear in the file; only the digital traces will appear. 5-54 L90 Line Current Differential System GE Multilin...
  • Page 185 436380 s 254460 s 3600000 ms 2727.5 235645200 s 340.9 29455200 s 26182800 s Changing any setting affecting data logger operation will clear any data that is currently in the log. NOTE GE Multilin L90 Line Current Differential System 5-55...
  • Page 186 D 1 e (EQ 5.6) – where: d = demand value after applying input quantity for time t (in minutes) D = input quantity (constant), and k = 2.3 / thermal 90% response time. 5-56 L90 Line Current Differential System GE Multilin...
  • Page 187: User-programmable Leds

     LEDS   TRIP & ALARM LEDS See page 5–60. MESSAGE   USER-PROGRAMMABLE See page 5–60. MESSAGE  LED1  USER-PROGRAMMABLE MESSAGE  LED2   USER-PROGRAMMABLE MESSAGE  LED48 GE Multilin L90 Line Current Differential System 5-57...
  • Page 188 The test responds to the position and rising edges of the control input defined by the set- LED TEST CONTROL ting. The control pulses must last at least 250 ms to take effect. The following diagram explains how the test is executed. 5-58 L90 Line Current Differential System GE Multilin...
  • Page 189 2. Once stage 2 has started, the pushbutton can be released. When stage 2 is completed, stage 3 will automatically start. The test may be aborted at any time by pressing the pushbutton. GE Multilin L90 Line Current Differential System 5-59...
  • Page 190 AR ENABLED LED 10 operand BREAKER 1 CLOSED LED 22 operand AR DISABLED LED 11 operand BREAKER 1 TROUBLE LED 23 operand AR RIP LED 12 operand LED 24 operand AR LO 5-60 L90 Line Current Differential System GE Multilin...
  • Page 191: User-programmable Self-tests

    Firmware revisions 3.2x and older use these three pushbuttons for manual breaker control. This functionality has been retained – if the breaker control feature is configured to use the three pushbuttons, they cannot be used as user-program- mable control pushbuttons. GE Multilin L90 Line Current Differential System 5-61...
  • Page 192 The location of the control pushbuttons are shown in the following figures. Control pushbuttons 842813A1.CDR Figure 5–9: CONTROL PUSHBUTTONS (ENHANCED FACEPLATE) An additional four control pushbuttons are included on the standard faceplate when the L90 is ordered with the twelve user- programmable pushbutton option. STATUS EVENT CAUSE...
  • Page 193: User-programmable Pushbuttons

    FlexLogic equations, protection elements, and control elements. Typical applications include breaker control, autorecloser blocking, and setting groups changes. The user-programmable pushbuttons are under the control level of password protection. The user-configurable pushbuttons for the enhanced faceplate are shown below. GE Multilin L90 Line Current Differential System 5-63...
  • Page 194 The pulse duration of the remote set, remote reset, or local pushbutton must be at least 50 ms to operate the push- button. This allows the user-programmable pushbuttons to properly operate during power cycling events and vari- ous system disturbances that may cause transient assertion of the operating signals. NOTE 5-64 L90 Line Current Differential System GE Multilin...
  • Page 195 PUSHBTN 1 RESET • PUSHBTN 1 LOCAL: This setting assigns the FlexLogic operand serving to inhibit pushbutton operation from the front panel pushbuttons. This locking functionality is not applicable to pushbutton autoreset. GE Multilin L90 Line Current Differential System 5-65...
  • Page 196 “Normal” if the setting is “High Priority” or “Normal”. PUSHBTN 1 MESSAGE • PUSHBUTTON 1 EVENTS: If this setting is enabled, each pushbutton state change will be logged as an event into event recorder. 5-66 L90 Line Current Differential System GE Multilin...
  • Page 197 Off = 0 SETTING SETTING Autoreset Delay Autoreset Function = Enabled = Disabled SETTING Drop-Out Timer TIMER FLEXLOGIC OPERAND 200 ms PUSHBUTTON 1 ON 842021A3.CDR Figure 5–14: USER-PROGRAMMABLE PUSHBUTTON LOGIC (Sheet 1 of 2) GE Multilin L90 Line Current Differential System 5-67...
  • Page 198: Flex State Parameters

    PATH: SETTINGS PRODUCT SETUP FLEX STATE PARAMETERS Range: FlexLogic operand  FLEX STATE PARAMETER  PARAMETERS Range: FlexLogic operand PARAMETER MESSAGE Range: FlexLogic operand PARAMETER MESSAGE  Range: FlexLogic operand PARAMETER 256: MESSAGE 5-68 L90 Line Current Differential System GE Multilin...
  • Page 199: User-definable Displays

    INVOKE AND SCROLL play, not at the first user-defined display. The pulses must last for at least 250 ms to take effect. INVOKE AND SCROLL GE Multilin L90 Line Current Differential System 5-69...
  • Page 200 While viewing a user display, press the ENTER key and then select the ‘Yes” option to remove the display from the user display list. Use the MENU key again to exit the user displays menu. 5-70 L90 Line Current Differential System GE Multilin...
  • Page 201: Installation

    "Programmed" state. UNIT NOT PROGRAMMED setting allows the user to uniquely identify a relay. This name will appear on generated reports. RELAY NAME GE Multilin L90 Line Current Differential System 5-71...
  • Page 202: Remote Resources Configuration

    Bricks. Remote resources settings configure the point-to-point connection between specific fiber optic ports on the L90 process card and specific Brick. The relay is then configured to measure spe- cific currents, voltages and contact inputs from those Bricks, and to control specific outputs.
  • Page 203: System Setup

    1000:1 CT before summation. If a protection element is set up to act on SRC 1 currents, then a pickup level of 1 pu will operate on 1000 A primary. The same rule applies for current sums from CTs with different secondary taps (5 A and 1 A). GE Multilin L90 Line Current Differential System 5-73...
  • Page 204: Power System

    5-74 L90 Line Current Differential System GE Multilin...
  • Page 205: Signal Sources

    FREQUENCY TRACKING frequency applications. NOTE The frequency tracking feature functions only when the L90 is in the “Programmed” mode. If the L90 is “Not Pro- grammed”, then metering values are available but can exhibit significant errors. NOTE The nominal system frequency should be selected as 50 Hz or 60 Hz only. The FREQUENCY AND PHASE REFERENCE setting, used as a reference for calculating all angles, must be identical for all terminals.
  • Page 206 0.02 pu; thus by default the disturbance detector responds to a change of 0.04 pu. The metering sensitivity setting ( PROD-   ) controls the sensitivity of the disturbance detector UCT SETUP DISPLAY PROPERTIES CURRENT CUT-OFF LEVEL accordingly. 5-76 L90 Line Current Differential System GE Multilin...
  • Page 207 Figure 5–18: EXAMPLE USE OF SOURCES Y LV D HV SRC 1 SRC 2 SRC 3 Phase CT F1+F5 None Ground CT None None Phase VT None None Aux VT None None GE Multilin L90 Line Current Differential System 5-77...
  • Page 208: L90 Power System

    MESSAGE CHANGE: 1.5 ms Any changes to the L90 power system settings will change the protection system configuration. As such, the 87L protection at all L90 protection system terminals must be temporarily disabled to allow the relays to acknowledge NOTE the new settings.
  • Page 209 The effect of charging current compensation is viewed in the METERING  actual values menu. This effect is very dependent on CT and VT accuracy. NOTE 87L DIFFERENTIAL CURRENT GE Multilin L90 Line Current Differential System 5-79...
  • Page 210 LOCAL (TERMINAL 1 and TERMINAL 2) ID NUMBER: In installations using multiplexers or modems for communica- tion, it is desirable to ensure the data used by the relays protecting a given line comes from the correct relays. The L90 performs this check by reading the ID number contained in the messages sent by transmitting relays and comparing this ID to the programmed correct ID numbers by the receiving relays.
  • Page 211 • BLOCK GPS TIME REF: This setting signals to the L90 that the time reference is not valid. The time reference may be not accurate due to problems with the GPS receiver. The user must to be aware of the case when a GPS satellite receiver loses its satellite signal and reverts to its own calibrated crystal oscillator.
  • Page 212 5.4 SYSTEM SETUP 5 SETTINGS Figure 5–20: CHANNEL ASYMMETRY COMPENSATION LOGIC 5-82 L90 Line Current Differential System GE Multilin...
  • Page 213: Breakers

    Range: 0.000 to 65.535 s in steps of 0.001 MANUAL CLOSE RECAL1 MESSAGE TIME: 0.000 s Range: FlexLogic operand BREAKER 1 OUT OF SV: MESSAGE Range: Disabled, Enabled BREAKER 1 EVENTS: MESSAGE Disabled GE Multilin L90 Line Current Differential System 5-83...
  • Page 214 1. The number of breaker control elements is dependent on the number of CT/VT modules specified with the L90. The follow- ing settings are available for each breaker control element.
  • Page 215 5 SETTINGS 5.4 SYSTEM SETUP Figure 5–21: DUAL BREAKER CONTROL SCHEME LOGIC (Sheet 1 of 2) IEC 61850 functionality is permitted when the L90 is in “Programmed” mode and not in the local control mode. NOTE GE Multilin L90 Line Current Differential System...
  • Page 216 5.4 SYSTEM SETUP 5 SETTINGS Figure 5–22: DUAL BREAKER CONTROL SCHEME LOGIC (Sheet 2 of 2) 5-86 L90 Line Current Differential System GE Multilin...
  • Page 217: Disconnect Switches

    For greater security in determination of the switch pole position, both the 52/a and 52/b auxiliary contacts are used with reporting of the discrepancy between them. The number of available disconnect switches depends on the number of the CT/VT modules ordered with the L90. •...
  • Page 218 SWITCH 1 ALARM DELAY: This setting specifies the delay interval during which a disagreement of status among the three-pole position tracking operands will not declare a pole disagreement. This allows for non-simultaneous operation of the poles. IEC 61850 functionality is permitted when the L90 is in “Programmed” mode and not in the local control mode. NOTE 5-88...
  • Page 219 5 SETTINGS 5.4 SYSTEM SETUP Figure 5–23: DISCONNECT SWITCH SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-89...
  • Page 220: Flexcurves

    1.03 pu. It is recommended to set the two times to a similar value; otherwise, the linear approximation may result in NOTE undesired behavior for the operating quantity that is close to 1.00 pu. 5-90 L90 Line Current Differential System GE Multilin...
  • Page 221 The multiplier and adder settings only affect the curve portion of the characteristic and not the MRT and HCT set- tings. The HCT settings override the MRT settings for multiples of pickup greater than the HCT ratio. NOTE GE Multilin L90 Line Current Differential System 5-91...
  • Page 222 EnerVista UR Setup software generates an error message and discards the proposed changes. NOTE e) STANDARD RECLOSER CURVES The standard recloser curves available for the L90 are displayed in the following graphs. 5-92 L90 Line Current Differential System...
  • Page 223 842723A1.CDR Figure 5–27: RECLOSER CURVES GE101 TO GE106 GE142 GE138 GE120 GE113 0.05 7 8 9 10 12 CURRENT (multiple of pickup) 842725A1.CDR Figure 5–28: RECLOSER CURVES GE113, GE120, GE138 AND GE142 GE Multilin L90 Line Current Differential System 5-93...
  • Page 224 Figure 5–29: RECLOSER CURVES GE134, GE137, GE140, GE151 AND GE201 GE152 GE141 GE131 GE200 7 8 9 10 12 CURRENT (multiple of pickup) 842728A1.CDR Figure 5–30: RECLOSER CURVES GE131, GE141, GE152, AND GE200 5-94 L90 Line Current Differential System GE Multilin...
  • Page 225 Figure 5–31: RECLOSER CURVES GE133, GE161, GE162, GE163, GE164 AND GE165 GE132 GE139 GE136 GE116 0.05 GE117 GE118 0.02 0.01 7 8 9 10 12 CURRENT (multiple of pickup) 842726A1.CDR Figure 5–32: RECLOSER CURVES GE116, GE117, GE118, GE132, GE136, AND GE139 GE Multilin L90 Line Current Differential System 5-95...
  • Page 226 Figure 5–33: RECLOSER CURVES GE107, GE111, GE112, GE114, GE115, GE121, AND GE122 GE202 GE135 GE119 7 8 9 10 12 CURRENT (multiple of pickup) 842727A1.CDR Figure 5–34: RECLOSER CURVES GE119, GE135, AND GE202 5-96 L90 Line Current Differential System GE Multilin...
  • Page 227: Phasor Measurement Unit

    MESSAGE  NETWORK The L90 Line Current Differential System is provided with an optional phasor measurement unit feature. This feature is specified as a software option at the time of ordering. The number of phasor measurement units available is also dependent on this option. Refer to the Ordering section of chapter 2 for additional details.
  • Page 228 Precise time input to the relay from the international time standard, via either IRIG-B or PTP, is vital for correct syn- chrophasor measurement and reporting. For IRIG-B, a DC level shift IRIG-B receiver must be used for the phasor measurement unit to output proper synchrophasor values. NOTE 5-98 L90 Line Current Differential System GE Multilin...
  • Page 229 The number of descriptions are equal to the number of bits configured in the 16 bit digital status word. All bitstrings less than or equal to 32 bits in length map into a 32 bit bitstring in an IEC 61850-90-5 dataset. NOTE GE Multilin L90 Line Current Differential System 5-99...
  • Page 230 From each PMU the user selects the phasor information of interest that is mapped into the selected aggregator datset(s). For version 7.0 only FCDA data is supported. Figure 5–38: DATA SET CREATED FROM USER SELECTED INTERNAL ITEMS 5-100 L90 Line Current Differential System GE Multilin...
  • Page 231 CONFIGURATION EXAMPLE: CFG-2 BASED CONFIGURATION (USING IEC61850-90-5) The L90 is expected to send the CFG-2 file (IEEE C37.118 config. file) upon request from the upstream synchrophasor devices (e.g., P30) without stopping R-SV multicasting, see figure below. The primary domain controller (PDC) does not need to use a stop/start data stream command if the UR protocol is set to IEC61850-90-5 prior to requesting the configura- tion via CFG-2 (IEEE C37.118 config.
  • Page 232  UNIT 1  CONFIGURATION  PMU 1 See page 5-106. MESSAGE  COMMUNICATION  PMU 1 See page 5-108. MESSAGE  TRIGGERING  PMU 1 See page 5-115. MESSAGE  RECORDING 5-102 L90 Line Current Differential System GE Multilin...
  • Page 233 Range: 1 to 65534 in steps of 1 PMU 1 IDCODE: MESSAGE Default: 1 Range: 32-character ASCII string truncated to 16 PMU 1 STN: MESSAGE characters if mapped into C37.118 Default: GE-UR-PMU GE-UR-PMU Range: Available signal sources PMU 1 SIGNAL SOURCE: MESSAGE Default: SRC 1 SRC 1...
  • Page 234 • PMU 1 SIGNAL SOURCE: This setting specifies one of the available L90 signal sources for processing in the PMU. Note that any combination of voltages and currents can be configured as a source. The current channels could be con- figured as sums of physically connected currents.
  • Page 235 5.4 SYSTEM SETUP (50 Hz), the L90 will generate a reporting mismatch message if the selected rate is not set as 10 Hz, 12 Hz, 15 Hz, 20 Hz, 30 Hz, 60 Hz, or 120 Hz (or 10 Hz, 25 Hz, 50 Hz or 100 Hz when the system frequency is 50 Hz) when entered via the keypad or software;...
  • Page 236 PMU1 PORT D-CH-16 MESSAGE NORMAL STATE: Off This section configures the phasor measurement unit (PMU) communication functions. • PMU1 COMM PORT: This setting specifies the communication port for transmission of the PMU data. 5-106 L90 Line Current Differential System GE Multilin...
  • Page 237 PMU1 PORT D-CH-1 NORMAL STATE to PMU1 PORT D-CH-16 NORMAL STATE: These settings allow for specify- ing a normal state for each digital channel. These states are transmitted in configuration frames to the data concentra- tor. GE Multilin L90 Line Current Differential System 5-107...
  • Page 238  PMU 1 USER PMU1 USER TRIGGER:  TRIGGER The user trigger allows customized triggering logic to be constructed from FlexLogic™. The entire triggering logic is refreshed once every two power system cycles. 5-108 L90 Line Current Differential System GE Multilin...
  • Page 239 L90 standards. This element requires the frequency is above the minimum measurable value. If the frequency is below this value, such as when the circuit is de-energized, the trigger will drop out.
  • Page 240 PMU 1 VOLT TRIGGER DPO TIME: This setting could be used to extend the trigger after the situation returned to nor- mal. This setting is of particular importance when using the recorder in the forced mode (recording as long as the trig- gering condition is asserted). 5-110 L90 Line Current Differential System GE Multilin...
  • Page 241 PMU 1 CURR TRIGGER DPO TIME: This setting could be used to extend the trigger after the situation returned to nor- mal. This setting is of particular importance when using the recorder in the forced mode (recording as long as the trig- gering condition is asserted). GE Multilin L90 Line Current Differential System 5-111...
  • Page 242 For single-phase power, 1 pu is a product of 1 pu voltage and 1 pu current, or the product of nominal second- ary voltage, the VT ratio and the nominal primary current. For the three-phase power, 1 pu is three times that for a sin- gle-phase power. The comparator applies a 3% hysteresis. 5-112 L90 Line Current Differential System GE Multilin...
  • Page 243 S > APPARENT PICKUP APPARENT POWER, SB S > APPARENT PICKUP APPARENT POWER, SC S > APPARENT PICKUP 3P APPARENT POWER, S S > 3*(APPARENT PICKUP) 847003A1.CDR Figure 5–45: POWER TRIGGER SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-113...
  • Page 244 PMU 1 df/dt TRIGGER DPO TIME: PMU 1 SIGNAL FLEXLOGIC OPERAND SOURCE: df/dt > RAISE PMU 1 ROCOF TRIGGER ROCOF, df/dt –df/dt > FALL 847000A1.CDR Figure 5–46: RATE OF CHANGE OF FREQUENCY TRIGGER SCHEME LOGIC 5-114 L90 Line Current Differential System GE Multilin...
  • Page 245 When the protocol selection is set via the software or keypad, all aggregators whose protocol is not set to None will be set to the last protocol saved (i.e., C37.118 or IEC61850-90-5) to any aggregators, as both C37.118 and IEC61850-90-5 simultaineous streaming of both R-SV values is not possible. NOTE GE Multilin L90 Line Current Differential System 5-115...
  • Page 246 AGTR1 PDC CNTRL 3 Phasor data concentrator asserts control bit 3 as received via the network.  as above AGTR1 PDC CNTRL 16 Phasor data concentrator asserts control bit 16, as received via the network. L90 Line Current Differential System GE Multilin...
  • Page 247 Default: 4 Range: 0 to 252 MSVCB 1 IP CLASS: MESSAGE Default: 46 Range: 0 to 4095 MSVCB 1 VID: MESSAGE Default: 0 Range: 0 to 16383 MSVCB 1 APPID: MESSAGE Default: 0 GE Multilin L90 Line Current Differential System 5-117...
  • Page 248 MSVCB 1 Security: This setting selects what level of security and authentication is used, see table below, and is in the form of an enumeration as per standard. The range is 1, 2 and 3. Shaded settings in table below are not supported in firmware 7.0. ENUMERATION AUTHENTICATION ENCRYPTION NOTE 5-118 L90 Line Current Differential System GE Multilin...
  • Page 249 NETWORK UDP PORT 1: This setting selects the first UDP port that will be used for network reporting. • NETWORK UDP PORT 2: This setting selects the second UDP port that will be used for network reporting. GE Multilin L90 Line Current Differential System 5-119...
  • Page 250: Flexlogic

    Figure 5–48: UR ARCHITECTURE OVERVIEW The states of all digital signals used in the L90 are represented by flags (or FlexLogic operands, which are described later in this section). A digital “1” is represented by a 'set' flag. Any external contact change-of-state can be used to block an ele- ment from operating, as an input to a control feature in a FlexLogic equation, or to operate a contact output.
  • Page 251 Some types of operands are present in the relay in multiple instances; e.g. contact and remote inputs. These types of oper- ands are grouped together (for presentation purposes only) on the faceplate display. The characteristics of the different types of operands are listed in the table below. Table 5–9: L90 FLEXLOGIC OPERAND TYPES OPERAND TYPE STATE...
  • Page 252 Exceeded maximum CRC error threshold on channel 2 87L DIFF CH1 ID FAIL The ID check for a peer L90 on channel 1 has failed 87L DIFF CH2 ID FAIL The ID check for a peer L90 on channel 2 has failed...
  • Page 253 5 SETTINGS 5.5 FLEXLOGIC Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 2 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION ELEMENT: AR ENABLED Autoreclosure is enabled and ready to perform Autoreclose AR DISABLED Autoreclosure is disabled (1P/3P) AR RIP Autoreclosure is in “reclose-in-progress” state...
  • Page 254 5.5 FLEXLOGIC 5 SETTINGS Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 3 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION ELEMENT: BREAKER 1 OFF CMD Breaker 1 open command initiated Breaker control BREAKER 1 ON CMD Breaker 1 close command initiated BREAKER 1 A BAD ST...
  • Page 255 5 SETTINGS 5.5 FLEXLOGIC Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 4 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION ELEMENT: GND DIST Z1 PKP Ground distance zone 1 has picked up Ground distance GND DIST Z1 OP Ground distance zone 1 has operated...
  • Page 256 5.5 FLEXLOGIC 5 SETTINGS Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 5 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION ELEMENT: OPEN POLE OP ФA Open pole condition is detected in phase A Open pole detector OPEN POLE OP ФB Open pole condition is detected in phase B OPEN POLE OP ФC...
  • Page 257 5 SETTINGS 5.5 FLEXLOGIC Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 6 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION ELEMENT: PHASE OV1 PKP At least one phase of overvoltage 1 has picked up Phase overvoltage PHASE OV1 OP At least one phase of overvoltage 1 has operated...
  • Page 258 5.5 FLEXLOGIC 5 SETTINGS Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 7 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION ELEMENT: POTT OP Permissive over-reaching transfer trip has operated POTT POTT TX1 Permissive over-reaching transfer trip asserts transit bit number 1...
  • Page 259 5 SETTINGS 5.5 FLEXLOGIC Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 8 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION ELEMENT: SRC1 VT FUSE FAIL OP Source 1 VT fuse failure detector has operated VTFF (Voltage SRC1 VT FUSE FAIL DPO...
  • Page 260 5.5 FLEXLOGIC 5 SETTINGS Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 9 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION FIXED OPERANDS Logic = 0. Does nothing and may be used as a delimiter in an equation list; used as ‘Disable’ by other features.
  • Page 261 5 SETTINGS 5.5 FLEXLOGIC Table 5–10: L90 FLEXLOGIC OPERANDS (Sheet 10 of 10) OPERAND TYPE OPERAND SYNTAX OPERAND DESCRIPTION PASSWORD ACCESS LOC SETG OFF Asserted when local setting access is disabled. SECURITY ACCESS LOC SETG ON Asserted when local setting access is enabled.
  • Page 262: Flexlogic Rules

    A timer operator (for example, "TIMER 1") or virtual output assignment (for example, " = Virt Op 1") may only be used once. If this rule is broken, a syntax error will be declared. 5-132 L90 Line Current Differential System GE Multilin...
  • Page 263: Flexlogic Evaluation

    (i.e. Virtual Output 3). The final output must also be assigned to a virtual output as virtual output 4, which will be programmed in the contact output section to oper- ate relay H1 (that is, contact output H1). GE Multilin L90 Line Current Differential System 5-133...
  • Page 264 Until accustomed to using FlexLogic, it is suggested that a worksheet with a series of cells marked with the arbitrary parameter numbers be prepared, as shown below. 5-134 L90 Line Current Differential System GE Multilin...
  • Page 265 99: The final output of the equation is virtual output 4 which is parameter “= Virt Op 4". 98: The operator preceding the output is timer 2, which is operand “TIMER 2". Note that the settings required for the timer are established in the timer programming section. GE Multilin L90 Line Current Differential System 5-135...
  • Page 266 It is now possible to check that the selection of parameters will produce the required logic by converting the set of parame- ters into a logic diagram. The result of this process is shown below, which is compared to the logic for virtual output 4 dia- gram as a check. 5-136 L90 Line Current Differential System GE Multilin...
  • Page 267 In the expression above, the virtual output 4 input to the four-input OR is listed before it is created. This is typical of a form of feedback, in this case, used to create a seal-in effect with the latch, and is correct. GE Multilin L90 Line Current Differential System 5-137...
  • Page 268: Flexlogic Equation Editor

    TIMER 1 PICKUP DELAY: Sets the time delay to pickup. If a pickup delay is not required, set this function to "0". • TIMER 1 DROPOUT DELAY: Sets the time delay to dropout. If a dropout delay is not required, set this function to "0". 5-138 L90 Line Current Differential System GE Multilin...
  • Page 269: Flexelements

    The element can be programmed to respond either to a signal level or to a rate-of-change (delta) over a pre-defined period of time. The output operand is asserted when the operating signal is higher than a threshold or lower than a threshold as per user's choice. GE Multilin L90 Line Current Differential System 5-139...
  • Page 270 The FLEXELEMENT 1 DIRECTION following figure explains the application of the FLEXELEMENT 1 DIRECTION FLEXELEMENT 1 PICKUP FLEXELEMENT 1 HYS- settings. TERESIS 5-140 L90 Line Current Differential System GE Multilin...
  • Page 271 DIRECTION = Under; FLEXELEMENT INPUT MODE = Signed; FlexElement 1 OpSig FLEXELEMENT 1 PKP FLEXELEMENT DIRECTION = Under; FLEXELEMENT INPUT MODE = Absolute; FlexElement 1 OpSig 842706A2.CDR Figure 5–58: FLEXELEMENT INPUT MODE SETTING GE Multilin L90 Line Current Differential System 5-141...
  • Page 272 “Delta”. FLEXELEMENT 1 COMP MODE This setting specifies the pickup delay of the element. The setting FLEXELEMENT 1 PKP DELAY FLEXELEMENT 1 RST DELAY specifies the reset delay of the element. 5-142 L90 Line Current Differential System GE Multilin...
  • Page 273: Non-volatile Latches

    Off=0 LATCH 1 ON Dominant LATCH 1 OFF Previous Previous SETTING State State LATCH 1 SET: Off=0 RESET 842005A1.CDR Figure 5–59: NON-VOLATILE LATCH OPERATION TABLE (N = 1 to 16) AND LOGIC GE Multilin L90 Line Current Differential System 5-143...
  • Page 274: Grouped Elements

    Each of the six setting group menus is identical. Setting group 1 (the default active group) automatically becomes active if no other group is active (see the Control elements section for additional details). 5-144 L90 Line Current Differential System GE Multilin...
  • Page 275: Line Differential Element

    Range: 1 to 50% in steps of 1 CURRENT DIFF GND MESSAGE RESTRAINT: 25% Range: 0.00 to 5.00 s in steps of 0.01 CURRENT DIFF GND MESSAGE DELAY: 0.10 s Range: Disabled, Enabled CURRENT DIFF DTT: MESSAGE Enabled GE Multilin L90 Line Current Differential System 5-145...
  • Page 276 CURRENT DIFF DTT: This setting enables and disables the sending of a DTT by the current differential element on per single-phase basis to remote devices. To allow the L90 to restart from master-master to master-slave mode (very important on three-terminal applications), must be set to “Enabled”.
  • Page 277 5 SETTINGS 5.6 GROUPED ELEMENTS Figure 5–60: CURRENT DIFFERENTIAL SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-147...
  • Page 278 The assigned current element should be mapped to appropriate output contact(s) to trip the stub bus breakers. It should be blocked unless disconnect is open. To prevent 87L tripping from remote L90 relays still protecting the line, the auxiliary contact of line disconnect switch (logic “1” when line switch is open) should be assigned to block the local 87L function by using the setting.
  • Page 279 5 SETTINGS 5.6 GROUPED ELEMENTS SETTING STUB BUS FUNCTION: Disabled=0 Enabled=1 SETTING STUB BUS DISCONNECT: FLEXLOGIC OPERAND Off=0 STUB BUS OP SETTING STUB BUS TRIGGER: Off=0 831012A3.CDR Figure 5–61: STUB BUS SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-149...
  • Page 280: Line Pickup

    2 or excessive phase current within eight power cycles after the autorecloser issues a close command results in the FlexLogic™ operand. For security, the overcurrent trip is supervised LINE PICKUP RCL TRIP 5-150 L90 Line Current Differential System GE Multilin...
  • Page 281 1 extension functionality if external autoreclosure is employed. Another zone 1 extension approach is to permanently apply an overreaching zone, and reduce the reach when reclosing. This philosophy can be programmed via the autore- close scheme. Figure 5–62: LINE PICKUP SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-151...
  • Page 282: Distance

    (logic 1), the distance functions become memory-polarized regardless of the positive-sequence voltage magnitude at this time. When the selected operand is de-asserted (logic 0), the distance functions follow other conditions of the memory volt- age logic. 5-152 L90 Line Current Differential System GE Multilin...
  • Page 283 NOTE The distance zones of the L90 are identical to that of the UR-series D60 Line Distance Relay. For additional infor- mation on the L90 distance functions, please refer to Chapter 8 of the D60 manual, available on the GE EnerVista CD or free of charge on the GE Multilin web page.
  • Page 284 PHS DIST Z1 DIR: All phase distance zones are reversible. The forward direction is defined by the PHS DIST Z1 RCA setting, whereas the reverse direction is shifted 180° from that angle. The non-directional zone spans between the for- 5-154 L90 Line Current Differential System GE Multilin...
  • Page 285 COMP LIMIT DIR COMP LIMIT DIR COMP LIMIT DIR RCA 837720A1.CDR Figure 5–64: DIRECTIONAL MHO DISTANCE CHARACTERISTIC COMP LIMIT REV REACH 837802A1.CDR Figure 5–65: NON-DIRECTIONAL MHO DISTANCE CHARACTERISTIC GE Multilin L90 Line Current Differential System 5-155...
  • Page 286 Figure 5–66: DIRECTIONAL QUADRILATERAL PHASE DISTANCE CHARACTERISTIC COMP LIMIT COMP LIMIT LFT BLD RCA RGT BLD RCA -LFT BLD RGT BLD REV REACH COMP LIMIT COMP LIMIT 837803A1.CDR Figure 5–67: NON-DIRECTIONAL QUADRILATERAL PHASE DISTANCE CHARACTERISTIC 5-156 L90 Line Current Differential System GE Multilin...
  • Page 287 DIR COMP LIMIT = 60 RGT BLD RCA = 90 RGT BLD RCA = 80 LFT BLD RCA = 90 LFT BLD RCA = 80 837723A1.CDR Figure 5–69: QUADRILATERAL DISTANCE CHARACTERISTIC SAMPLE SHAPES GE Multilin L90 Line Current Differential System 5-157...
  • Page 288 The setting is an angle of reach impedance as shown in the distance characteristic figures shown earlier. This setting is independent from , the characteristic angle of an PHS DIST Z1 DIR RCA extra directional supervising function. 5-158 L90 Line Current Differential System GE Multilin...
  • Page 289 PHS DIST Z1 BLK: This setting enables the user to select a FlexLogic™ operand to block a given distance element. VT fuse fail detection is one of the applications for this setting. GE Multilin L90 Line Current Differential System 5-159...
  • Page 290 PH DIST Z1 SUPN IBC PH DIST Z1 SUPN ICA OPEN POLE OP ** ** D60, L60, and L90 only. Other UR-series models apply regular current seal-in for zone 1. 837017A8.CDR Figure 5–71: PHASE DISTANCE ZONE 1 OP SCHEME Figure 5–72: PHASE DISTANCE ZONE 2 OP SCHEME...
  • Page 291 5 SETTINGS 5.6 GROUPED ELEMENTS Figure 5–73: PHASE DISTANCE ZONES 3 AND HIGHER OP SCHEME D60, L60, and L90 only FLEXLOGIC OPERANDS OPEN POLE BLK AB OPEN POLE BLK BC OPEN POLE BLK CA SETTINGS PH DIST Z1 DIR PH DIST Z1 SHAPE...
  • Page 292 Range: 60 to 90° in steps of 1 GND DIST Z1 QUAD MESSAGE LFT BLD RCA: 85° Range: 0.050 to 30.000 pu in steps of 0.001 GND DIST Z1 MESSAGE SUPV: 0.200 pu 5-162 L90 Line Current Differential System GE Multilin...
  • Page 293 The directional and non-directional quadrilateral ground distance characteristics are shown below. The directional and non-directional mho ground distance characteristics are the same as those shown for the phase distance element in the previous sub-section. GE Multilin L90 Line Current Differential System 5-163...
  • Page 294 DISTANCE SOURCE zero-sequence impedance between the lines and the positive-sequence impedance of the protected line. It is impera- tive to set this setting to zero if the compensation is not to be performed. 5-164 L90 Line Current Differential System GE Multilin...
  • Page 295 This setting applies only to the GND DIST Z1 QUAD RGT BLD RCA quadrilateral characteristic and should be set with consideration to the maximum load current and required resistive coverage. GE Multilin L90 Line Current Differential System 5-165...
  • Page 296 GND DIST Z1 PKP C FLEXLOGIC OPERANDS GND DIST Z1 SUPN IN OPEN POLE OP ** ** D60, L60, and L90 only. Other UR-series models apply regular current seal-in for zone 1. 837018A7.CDR Figure 5–77: GROUND DISTANCE ZONE 1 OP SCHEME 5-166...
  • Page 297 3 or 4 to zone 2. The desired zones should be assigned in the trip output element to accomplish this NOTE functionality. Figure 5–79: GROUND DISTANCE ZONES 3 AND HIGHER OP SCHEME GE Multilin L90 Line Current Differential System 5-167...
  • Page 298 5.6 GROUPED ELEMENTS 5 SETTINGS Figure 5–80: GROUND DISTANCE ZONE 1 SCHEME LOGIC 5-168 L90 Line Current Differential System GE Multilin...
  • Page 299 The supervision is biased toward operation in order to avoid compromising the sensitivity of ground distance elements at low signal levels. Otherwise, the reverse fault condition that generates concern will have high polarizing levels so that a cor- rect reverse fault decision can be reliably made. GE Multilin L90 Line Current Differential System 5-169...
  • Page 300: Power Swing Detect

    LIMIT ANGLE: 120° Range: 40 to 140° in steps of 1 POWER SWING MIDDLE MESSAGE LIMIT ANGLE: 90° Range: 40 to 140° in steps of 1 POWER SWING INNER MESSAGE LIMIT ANGLE: 60° 5-170 L90 Line Current Differential System GE Multilin...
  • Page 301 Different protection elements respond differently to power swings. If tripping is required for faults during power swing condi- tions, some elements may be blocked permanently (using the operand), and others may be blocked POWER SWING BLOCK and dynamically unblocked upon fault detection (using the operand). POWER SWING UN/BLOCK GE Multilin L90 Line Current Differential System 5-171...
  • Page 302 The element can be set to use either lens (mho) or rectangular (quadrilateral) characteristics as illustrated below. When set to “Mho”, the element applies the right and left blinders as well. If the blinders are not required, their settings should be set high enough to effectively disable the blinders. 5-172 L90 Line Current Differential System GE Multilin...
  • Page 303 5 SETTINGS 5.6 GROUPED ELEMENTS Figure 5–83: POWER SWING DETECT MHO OPERATING CHARACTERISTICS Figure 5–84: EFFECTS OF BLINDERS ON THE MHO CHARACTERISTICS GE Multilin L90 Line Current Differential System 5-173...
  • Page 304 POWER SWING SHAPE: This setting selects the shapes (either “Mho” or “Quad”) of the outer, middle and, inner char- acteristics of the power swing detect element. The operating principle is not affected. The “Mho” characteristics use the left and right blinders. 5-174 L90 Line Current Differential System GE Multilin...
  • Page 305 (the actual trip may be delayed as per the setting). Therefore, this angle must be selected in consider- TRIP MODE ation to the power swing angle beyond which the system becomes unstable and cannot recover. GE Multilin L90 Line Current Differential System 5-175...
  • Page 306 The blocking signal resets the output operand but does not stop the out-of-step tripping sequence. POWER SWING TRIP 5-176 L90 Line Current Differential System GE Multilin...
  • Page 307 K_0, K_2 - three times the average change over last power cycle 842008A1.CDR K_1 - four times the average change over last power cycle Figure 5–87: POWER SWING DETECT SCHEME LOGIC (2 of 3) GE Multilin L90 Line Current Differential System 5-177...
  • Page 308 L1 AND L4 LATCHES ARE SET DOMINANT L2, L3 AND L5 LATCHES ARE RESET DOMINANT Off=0 FLEXLOGIC OPERAND POWER SWING OUTGOING 827841A4.CDR Figure 5–88: POWER SWING DETECT SCHEME LOGIC (3 of 3) 5-178 L90 Line Current Differential System GE Multilin...
  • Page 309: Load Encroachment

    The element operates if the positive-sequence voltage is above a settable level and asserts its output signal that can be used to block selected protection elements such as distance or phase overcurrent. The following figure shows an effect of the load encroachment characteristics used to block the quadrilateral distance element. GE Multilin L90 Line Current Differential System 5-179...
  • Page 310 If the voltage is below this threshold a blocking signal will not be asserted by the element. When selecting this setting one must remember that the L90 measures the phase-to-ground sequence voltages regardless of the VT connection.
  • Page 311: Phase Current

     DIRECTIONAL 2 b) INVERSE TIME OVERCURRENT CHARACTERISTICS The inverse time overcurrent curves used by the time overcurrent elements are the IEEE, IEC, GE Type IAC, and I t stan- dard curve shapes. This allows for simplified coordination with downstream devices.
  • Page 312 4.827 38.634 22.819 14.593 11.675 10.130 9.153 8.470 7.960 7.562 7.241 51.512 30.426 19.458 15.567 13.507 12.204 11.294 10.614 10.083 9.654 10.0 64.390 38.032 24.322 19.458 16.883 15.255 14.117 13.267 12.604 12.068 5-182 L90 Line Current Differential System GE Multilin...
  • Page 313 1.835 1.067 0.668 0.526 0.451 0.404 0.371 0.346 0.327 0.311 0.80 2.446 1.423 0.890 0.702 0.602 0.538 0.494 0.461 0.435 0.415 1.00 3.058 1.778 1.113 0.877 0.752 0.673 0.618 0.576 0.544 0.518 GE Multilin L90 Line Current Differential System 5-183...
  • Page 314 = characteristic constant, and T = reset time in seconds (assuming energy capacity is 100% RESET is “Timed”) RESET Table 5–19: GE TYPE IAC INVERSE TIME CURVE CONSTANTS IAC CURVE SHAPE IAC Extreme Inverse 0.0040 0.6379 0.6200 1.7872 0.2461...
  • Page 315 = Reset Time in seconds (assuming energy capacity is 100% and RESET: Timed) RESET RECLOSER CURVES: The L90 uses the FlexCurve feature to facilitate programming of 41 recloser curves. Please refer to the FlexCurve section in this chapter for additional details. GE Multilin...
  • Page 316 ‘Mvr’ times the setting. If the voltage restraint feature PHASE TOC1 PICKUP is disabled, the pickup level always remains at the setting value. 5-186 L90 Line Current Differential System GE Multilin...
  • Page 317 PHASE TOC1 C DPO Multiplier-Phase C PHASE TOC1 C OP SETTING PHASE TOC1 PKP PHASE TOC1 VOLT RESTRAINT: PHASE TOC1 OP Enabled PHASE TOC1 DPO 827072A4.CDR Figure 5–93: PHASE TIME OVERCURRENT 1 SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-187...
  • Page 318 PHASE IOC1 PKP SETTING PHASE IOC1 OP PHASE IOC1 BLOCK-B: PHASE IOC1 DPO Off = 0 SETTING 827033A6.VSD PHASE IOC1 BLOCK-C: Off = 0 Figure 5–94: PHASE INSTANTANEOUS OVERCURRENT 1 SCHEME LOGIC 5-188 L90 Line Current Differential System GE Multilin...
  • Page 319 CTs and the line-line voltage from the VTs, based on the 90° or quadrature connection. If there is a requirement to supervise overcurrent elements for flows in opposite directions, such as can happen through a bus-tie breaker, two phase directional elements should be programmed with opposite element characteristic angle (ECA) settings. GE Multilin L90 Line Current Differential System 5-189...
  • Page 320 10 ms must be added to all the instantaneous protection elements under the supervi- sion of the phase directional element. If current reversal is of a concern, a longer delay – in the order of 20 ms – may be needed. 5-190 L90 Line Current Differential System GE Multilin...
  • Page 321: Neutral Current

     NEUTRAL IOC1 See page 5-193. MESSAGE   NEUTRAL IOC2 See page 5-193. MESSAGE   NEUTRAL See page 5-194. MESSAGE  DIRECTIONAL OC1  NEUTRAL See page 5-194. MESSAGE  DIRECTIONAL OC2 GE Multilin L90 Line Current Differential System 5-191...
  • Page 322 NEUTRAL TOC1 PKP RESET: NEUTRAL TOC1 IN ≥ PICKUP NEUTRAL TOC1 DPO SOURCE: NEUTRAL TOC1 OP SETTING NEUTRAL TOC1 BLOCK: Off = 0 827034A3.VSD Figure 5–97: NEUTRAL TIME OVERCURRENT 1 SCHEME LOGIC 5-192 L90 Line Current Differential System GE Multilin...
  • Page 323 RESET DELAY : SETTING NEUTRAL IOC1 DPO NEUTRAL IOC1 OP 3( _0 - K _1 ) PICKUP NEUTRAL IOC1 BLOCK: Off=0 SETTING NEUTRAL IOC1 SOURCE: 827035A4.CDR Figure 5–98: NEUTRAL IOC1 SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-193...
  • Page 324     (EQ 5.19) – The positive-sequence restraint allows for more sensitive settings by counterbalancing spurious zero-sequence currents resulting from: • System unbalances under heavy load conditions. 5-194 L90 Line Current Differential System GE Multilin...
  • Page 325 1.5 of a power system cycle. The element is designed to emu- late an electromechanical directional device. Larger operating and polarizing signals will result in faster directional discrimi- nation bringing more security to the element operation. GE Multilin L90 Line Current Differential System 5-195...
  • Page 326 The low-side system impedance should be assumed minimal when checking for this condition. A similar sit- uation arises for a wye/delta/wye transformer, where current in one transformer winding neutral may reverse when faults on both sides of the transformer are considered. 5-196 L90 Line Current Differential System GE Multilin...
  • Page 327 NEUTRAL DIR OC1 REV PICKUP: This setting defines the pickup level for the overcurrent unit of the element in the reverse direction. When selecting this setting it must be kept in mind that the design uses a positive-sequence restraint technique for the “Calculated 3I0” mode of operation. GE Multilin L90 Line Current Differential System 5-197...
  • Page 328 5.6 GROUPED ELEMENTS 5 SETTINGS Figure 5–100: NEUTRAL DIRECTIONAL OVERCURRENT LOGIC 5-198 L90 Line Current Differential System GE Multilin...
  • Page 329: Wattmetric Ground Fault

    VT connected to the auxiliary channel bank of the relay). When the latter selection is made, the auxiliary channel must be identified by the user as a neutral voltage under the VT bank settings. This element will operate only if the aux- iliary voltage is configured as neutral. GE Multilin L90 Line Current Differential System 5-199...
  • Page 330   FlexCurve --------- - (EQ 5.22)   Again, the FlexCurve timer starts after the definite time timer expires. 5-200 L90 Line Current Differential System GE Multilin...
  • Page 331 1 FUNCTION: WATTMETRIC GND FLT 1 Enabled = 1 OC PKP DEL: WATT GND FLT 1 BLK: FLEXLOGIC OPERAND Off = 0 WATTMETRIC 1 PKP 837033A4.CDR Figure 5–102: WATTMETRIC ZERO-SEQUENCE DIRECTIONAL LOGIC GE Multilin L90 Line Current Differential System 5-201...
  • Page 332: Ground Current

    GROUND TOC 1 SETTING RESET: GROUND TOC1 PKP GROUND TOC1 GROUND TOC1 DPO IG ≥ PICKUP SOURCE: GROUND TOC1 OP SETTING GROUND TOC1 BLOCK: 827036A3.VSD Off = 0 Figure 5–103: GROUND TOC1 SCHEME LOGIC 5-202 L90 Line Current Differential System GE Multilin...
  • Page 333 Enabled = 1 SETTING DELAY: GROUND IOC1 GROUND IOC1 RESET SETTING PICKUP: DELAY: GROUND IOC1 SOURCE: IG ≥ PICKUP SETTING GROUND IOC1 BLOCK: 827037A4.VSD Off = 0 Figure 5–104: GROUND IOC1 SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-203...
  • Page 334: Negative Sequence Current

    < NEG SEQ PICKUP NEG SEQ TOC1 DPO NEG SEQ TOC1 BLOCK: NEG SEQ TOC1 OP Off=0 SETTING NEG SEQ TOC1 SOURCE: Neg Seq 827057A4.CDR Figure 5–105: NEGATIVE SEQUENCE TOC1 SCHEME LOGIC 5-204 L90 Line Current Differential System GE Multilin...
  • Page 335 SETTING NEG SEQ IOC1 DPO NEG SEQ IOC1 OP _2 - K _1 PICKUP NEG SEQ IOC1 BLOCK: Off=0 SETTING NEG SEQ IOC1 SOURCE: 827058A5.CDR Figure 5–106: NEGATIVE SEQUENCE IOC1 SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-205...
  • Page 336 The positive-sequence restraint allows for more sensitive settings by counterbalancing spurious negative-sequence and zero-sequence currents resulting from: • System unbalances under heavy load conditions. • Transformation errors of current transformers (CTs). • Fault inception and switch-off transients. 5-206 L90 Line Current Differential System GE Multilin...
  • Page 337 CT errors, since the current is low. The operating quantity depends on the way the test currents are injected into the L90. For single phase injection: = ⅓  (1 – K  I •...
  • Page 338 The element characteristic angle in the reverse direction is the angle set for the forward direction shifted by 180°. • NEG SEQ DIR OC1 FWD LIMIT ANGLE: This setting defines a symmetrical (in both directions from the ECA) limit angle for the forward direction. 5-208 L90 Line Current Differential System GE Multilin...
  • Page 339 When NEG SEQ DIR OC1 TYPE selecting this setting it must be kept in mind that the design uses a positive-sequence restraint technique. Figure 5–108: NEGATIVE SEQUENCE DIRECTIONAL OC1 SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-209...
  • Page 340: Breaker Failure

    Range: 0.001 to 30.000 pu in steps of 0.001 BF1 N AMP HISET MESSAGE PICKUP: 1.050 pu Range: 0.001 to 30.000 pu in steps of 0.001 BF1 PH AMP LOSET MESSAGE PICKUP: 1.050 pu 5-210 L90 Line Current Differential System GE Multilin...
  • Page 341 For the L90 relay, the protection trip signal initially sent to the breaker is already programmed as a trip output. The protection trip signal does not include other breaker commands that are not indicative of a fault in the protected zone.
  • Page 342 BREAKER FAILURE TIMER No. 2 (±1/8 cycle) INITIATE (1/8 cycle) BREAKER FAILURE CURRENT DETECTOR PICKUP (1/8 cycle) BREAKER FAILURE OUTPUT RELAY PICKUP (1/4 cycle) FAULT cycles OCCURS 827083A6.CDR Figure 5–109: BREAKER FAILURE MAIN PATH SEQUENCE 5-212 L90 Line Current Differential System GE Multilin...
  • Page 343 In microprocessor relays this time is not significant. In L90 relays, which use a Fourier transform, the calculated current magnitude will ramp-down to zero one power frequency cycle after the current is interrupted, and this lag should be included in the overall margin duration, as it occurs after current interruption.
  • Page 344 Upon operation of the breaker failure element for a single pole trip command, a three-pole trip command should be given via output operand BKR FAIL 1 TRIP OP 5-214 L90 Line Current Differential System GE Multilin...
  • Page 345 5 SETTINGS 5.6 GROUPED ELEMENTS Figure 5–111: SINGLE-POLE BREAKER FAILURE, INITIATE GE Multilin L90 Line Current Differential System 5-215...
  • Page 346 5.6 GROUPED ELEMENTS 5 SETTINGS Figure 5–112: SINGLE-POLE BREAKER FAILURE, TIMERS 5-216 L90 Line Current Differential System GE Multilin...
  • Page 347 5 SETTINGS 5.6 GROUPED ELEMENTS Figure 5–113: THREE-POLE BREAKER FAILURE, INITIATE GE Multilin L90 Line Current Differential System 5-217...
  • Page 348 5.6 GROUPED ELEMENTS 5 SETTINGS Figure 5–114: THREE-POLE BREAKER FAILURE, TIMERS 5-218 L90 Line Current Differential System GE Multilin...
  • Page 349: Voltage Elements

    ------------------ –   pickup where: T = operating time D = undervoltage delay setting (D = 0.00 operates instantaneously) V = secondary voltage applied to the relay = pickup level pickup GE Multilin L90 Line Current Differential System 5-219...
  • Page 350 The minimum voltage setting selects the operating voltage below which the element is blocked (a setting of “0” will allow a dead source to be considered a fault condition). 5-220 L90 Line Current Differential System GE Multilin...
  • Page 351 The input voltage is the phase-to-phase voltage, either measured directly from delta-connected VTs or as cal- culated from phase-to-ground (wye) connected VTs. The specific voltages to be used for each phase are shown below. GE Multilin L90 Line Current Differential System 5-221...
  • Page 352 FlexCurves A, B, or C) or be used as a definite time element. The setting applies only if NEUTRAL OV1 PICKUP DELAY setting is “Definite time”. The source assigned to this element must be configured for a phase VT. NEUTRAL OV1 CURVE 5-222 L90 Line Current Differential System GE Multilin...
  • Page 353 AUX UV1 EVENTS: MESSAGE Disabled The L90 contains one auxiliary undervoltage element for each VT bank. This element is intended for monitoring undervolt- age conditions of the auxiliary voltage. The selects the voltage level at which the time undervoltage ele- AUX UV1 PICKUP ment starts timing.
  • Page 354 AUX OV1 EVENTS: MESSAGE Disabled The L90 contains one auxiliary overvoltage element for each VT bank. This element is intended for monitoring overvoltage conditions of the auxiliary voltage. The nominal secondary voltage of the auxiliary voltage channel entered under SYSTEM ...
  • Page 355: Sensitive Directional Power

    The element has an adjustable characteristic angle and minimum operating power as shown in the Directional power char- acteristic diagram. The element responds to the following condition:    SMIN (EQ 5.26) GE Multilin L90 Line Current Differential System 5-225...
  • Page 356 SENSITIVE DIRECTIONAL POWER 1(2) value. The element has two independent (as to the pickup and delay settings) stages for alarm and trip, respectively. OPERATE RCA+ CALIBRATION SMIN RESTRAIN Figure 5–121: DIRECTIONAL POWER CHARACTERISTIC 5-226 L90 Line Current Differential System GE Multilin...
  • Page 357 DIR POWER 1 CALIBRATION: This setting allows the relay characteristic angle to change in steps of 0.05°. This may be useful when a small difference in VT and CT angular errors is to be compensated to permit more sensitive settings. GE Multilin L90 Line Current Differential System 5-227...
  • Page 358 DIR POWER 1 OP Three-phase reactive power (Q) DIR POWER 1 STG2 DPO DIR POWER 1 STG2 OP SETTING DIR POWER 1 STG2 DELAY: 100 ms 842003A3.CDR Figure 5–123: SENSITIVE DIRECTIONAL POWER SCHEME LOGIC 5-228 L90 Line Current Differential System GE Multilin...
  • Page 359: Supervising Elements

    DD CONTROL LOGIC: This setting is used to prevent operation of I_0 and I_2 logic of disturbance detector during conditions such as single breaker pole being open which leads to unbalanced load current in single-pole tripping schemes. Breaker auxiliary contact can be used for such scheme. GE Multilin L90 Line Current Differential System 5-229...
  • Page 360 OR LOWER) IN 0.02 pu SETTING FLEXLOGIC OPERAND STEPS USING THE HIGHEST VALUE OF 50DD SV DD LOGIC I_0 AND I_2. SEAL-IN: Off=0 SETTING DD NON-CURRENT SUPV: Off=0 827044A6.CDR Figure 5–124: DISTURBANCE DETECTOR SCHEME LOGIC 5-230 L90 Line Current Differential System GE Multilin...
  • Page 361 Autoreclosure disabled can be utilized, or the autoreclosure counter if, for example, the second trip is required to be a three-pole signal. Likewise, any operand representing a change in the power system configuration, can be applied. GE Multilin L90 Line Current Differential System 5-231...
  • Page 362 OPEN POLE OP A Φ OPEN POLE OP B Φ OPEN POLE OP C Φ OPEN POLE OP SETTING 87L TRIP FORCE 3-Φ = Off 831020A5.CDR Figure 5–125: 87L TRIP SCHEME LOGIC 5-232 L90 Line Current Differential System GE Multilin...
  • Page 363: Control Elements

    If more than one operate-type operand is required, it may be assigned directly from the trip bus menu. GE Multilin L90 Line Current Differential System 5-233...
  • Page 364 TRIP BUS 1 PKP = Enabled TRIP BUS 1 BLOCK = Off SETTINGS TRIP BUS 1 LATCHING = Enabled TRIP BUS 1 RESET = Off FLEXLOGIC OPERAND RESET OP 842023A1.CDR Figure 5–127: TRIP BUS LOGIC 5-234 L90 Line Current Differential System GE Multilin...
  • Page 365: Setting Groups

    The assigned operand is used to control the “On” state of a particular settings group. VIRTUAL OUTPUT 1 GE Multilin L90 Line Current Differential System 5-235...
  • Page 366: Selector Switch

    SELECTOR 1 3BIT ACK: MESSAGE Range: Restore, Synchronize, Sync/Restore SELECTOR 1 POWER-UP MESSAGE MODE: Restore Range: Self-reset, Latched, Disabled SELECTOR 1 TARGETS: MESSAGE Self-reset Range: Disabled, Enabled SELECTOR 1 EVENTS: MESSAGE Disabled 5-236 L90 Line Current Differential System GE Multilin...
  • Page 367 SELECTOR 1 3BIT A0, A1, and A2: These settings specify a three-bit control input of the selector. The three-bit con- trol word pre-selects the position using the following encoding convention: POSITION rest GE Multilin L90 Line Current Differential System 5-237...
  • Page 368 The selector position pre-selected via the stepping up control input has not been confirmed before the time out. SELECTOR 1 BIT ALARM The selector position pre-selected via the three-bit control input has not been confirmed before the time out. 5-238 L90 Line Current Differential System GE Multilin...
  • Page 369 3BIT A2 POS 1 POS 2 POS 3 POS 4 POS 5 POS 6 POS 7 BIT 0 BIT 1 BIT 2 STP ALARM BIT ALARM ALARM 842737A1.CDR Figure 5–129: TIME-OUT MODE GE Multilin L90 Line Current Differential System 5-239...
  • Page 370 Make the following changes to selector switch element in the    SETTINGS CONTROL ELEMENTS SELECTOR SWITCH menu to assign control to user programmable pushbutton 1 and contact inputs 1 through 3: SELECTOR SWITCH 1 5-240 L90 Line Current Differential System GE Multilin...
  • Page 371 SELECTOR 1 BIT ALARM 3-bit position out SELECTOR 1 ALARM SELECTOR 1 PWR ALARM SELECTOR 1 BIT 0 SELECTOR 1 BIT 1 SELECTOR 1 BIT 2 842012A2.CDR Figure 5–131: SELECTOR SWITCH LOGIC GE Multilin L90 Line Current Differential System 5-241...
  • Page 372: Trip Output

    START TMR Z2GR Inp1: MESSAGE Range: FlexLogic™ operand START TMR Z2GR Inp2: MESSAGE Range: FlexLogic™ operand BKR ΦA OPEN: MESSAGE Range: FlexLogic™ operand BKR ΦB OPEN: MESSAGE Range: FlexLogic™ operand BKR ΦC OPEN: MESSAGE 5-242 L90 Line Current Differential System GE Multilin...
  • Page 373 Assign a higher priority to pilot aided scheme outputs than to exclusively local inputs. The trip output element works in association with other L90 elements (refer to the Theory of operation chapter for a com- plete description of single-pole operations) that must be programmed and in-service for successful operation. The neces- sary elements are: recloser, breaker control, open pole detector, and phase selector.
  • Page 374 TRIP FORCE 3-POLE: Selects an operand that will force an input selected for single pole operation to produce a three pole operation. The FlexLogic™ operand is the recommended value for this setting. Power system con- AR DISABLED figurations or conditions which require such operations may be considered as well. 5-244 L90 Line Current Differential System GE Multilin...
  • Page 375 Typically this value should be set around half a power system cycle. This setting should be used only in single- pole tripping applications, when evolving faults are of importance, and slightly delayed operation on evolving faults could be traded for enhanced accuracy of single-pole tripping. GE Multilin L90 Line Current Differential System 5-245...
  • Page 376 5.7 CONTROL ELEMENTS 5 SETTINGS Figure 5–132: TRIP OUTPUT SCHEME LOGIC (Sheet 1 of 2) 5-246 L90 Line Current Differential System GE Multilin...
  • Page 377 5 SETTINGS 5.7 CONTROL ELEMENTS Figure 5–133: TRIP OUTPUT SCHEME LOGIC (Sheet 2 of 2) GE Multilin L90 Line Current Differential System 5-247...
  • Page 378: Underfrequency

    ≤ 0 < f PICKUP UNDERFREQ 1 OP UNDERFREQ 1 ACTUAL VALUES MIN VOLT / AMP: UNDERFREQ 1 SOURCE: ≥ Level Minimum VOLT / AMP Frequency 827079A8.CDR Figure 5–134: UNDERFREQUENCY SCHEME LOGIC 5-248 L90 Line Current Differential System GE Multilin...
  • Page 379: Overfrequency

    OVERFREQ 1 BLOCK: OVERFREQ 1 RESET OVERFREQ 1 PKP DELAY : Off = 0 OVERFREQ 1 DPO OVERFREQ 1 OP SETTING ≥ PICKUP OVERFREQ 1 SOURCE: Frequency 827832A5.CDR Figure 5–135: OVERFREQUENCY SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-249...
  • Page 380: Frequency Rate Of Change

    FREQ RATE 1 OC SUPV PICKUP: This setting defines minimum current level required for operation of the element. The supervising function responds to the positive-sequence current. Typical application includes load shedding. Set the pickup threshold to zero if no overcurrent supervision is required. 5-250 L90 Line Current Differential System GE Multilin...
  • Page 381 FREQ RATE 1 PKP FREQ RATE 1 MIN FREQUENCY: FREQ RATE 1 MAX FREQUENCY: F > MIN & F < MAX Calculate df/dt 832023A2.CDR Figure 5–136: FREQUENCY RATE OF CHANGE SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-251...
  • Page 382: Synchrocheck

    F. This time can be calculated by: ------------------------------- - (EQ 5.27) 360 ----------------- -  F 2   where: = phase angle difference in degrees; F = frequency difference in Hz. 5-252 L90 Line Current Differential System GE Multilin...
  • Page 383 COMBINATION SOURCE Y SOURCE Z Phase VTs and Phase VTs and Phase Phase Auxiliary VT Auxiliary VT Phase VTs and Phase VT Phase Phase Auxiliary VT Phase VT Phase VT Phase Phase GE Multilin L90 Line Current Differential System 5-253...
  • Page 384 The relay will use the phase channel of a three-phase set of voltages if pro- grammed as part of that source. The relay will use the auxiliary voltage channel only if that channel is programmed as part of the Source and a three-phase set is not. 5-254 L90 Line Current Differential System GE Multilin...
  • Page 385 5 SETTINGS 5.7 CONTROL ELEMENTS Figure 5–137: SYNCHROCHECK SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-255...
  • Page 386: Digital Elements

    Some versions of the digital input modules include an active voltage monitor circuit connected across form-A contacts. The voltage monitor circuit limits the trickle current through the output circuit (see technical specifications for form-A). 5-256 L90 Line Current Differential System GE Multilin...
  • Page 387 The settings to use digital element 1 to monitor the breaker trip circuit are indicated below (EnerVista UR Setup example shown): The PICKUP DELAY setting should be greater than the operating time of the breaker to avoid nuisance alarms. NOTE GE Multilin L90 Line Current Differential System 5-257...
  • Page 388 “Off”. In this case, the settings are as follows (EnerVista UR Setup example shown). Figure 5–140: TRIP CIRCUIT EXAMPLE 2 The wiring connection for two examples above is applicable to both form-A contacts with voltage monitoring and solid-state contact with voltage monitoring. NOTE 5-258 L90 Line Current Differential System GE Multilin...
  • Page 389: Digital Counters

    –2,147,483,648 counts, the counter will rollover to +2,147,483,647. • COUNTER 1 BLOCK: Selects the FlexLogic operand for blocking the counting operation. All counter operands are blocked. GE Multilin L90 Line Current Differential System 5-259...
  • Page 390 COUNTER 1 FROZEN: Off = 0 STORE DATE & TIME Date & Time SETTING COUNT1 FREEZE/RESET: Off = 0 827065A1.VSD SETTING COUNT1 FREEZE/COUNT: Off = 0 Figure 5–141: DIGITAL COUNTER SCHEME LOGIC 5-260 L90 Line Current Differential System GE Multilin...
  • Page 391: Monitoring Elements

    See page 5–276. MESSAGE   BROKEN CONDUCTOR 1 See page 5–279. MESSAGE   BROKEN CONDUCTOR 2 See page 5–279. MESSAGE   THERMAL OVERLOAD See page 5–281. MESSAGE  PROTECTION GE Multilin L90 Line Current Differential System 5-261...
  • Page 392 • BKR 1 ARC AMP LIMIT: Selects the threshold value above which the output operand is set. 5-262 L90 Line Current Differential System GE Multilin...
  • Page 393 BKR 1 ARCING AMP C Φ 827071A3.CDR BKR 1 OPERATING TIME A Φ BKR 1 OPERATING TIME B Φ BKR 1 OPERATING TIME C Φ BKR 1 OPERATING TIME Figure 5–143: BREAKER ARCING CURRENT SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-263...
  • Page 394 Breaker open, Voltage difference drop, and Measured flashover current through the breaker. Furthermore, the scheme is applicable for cases where either one or two sets of three-phase voltages are available across the breaker. 5-264 L90 Line Current Differential System GE Multilin...
  • Page 395 This application do not require detection of breaker status via a 52a contact, as it uses a voltage difference larger than the setting. However, monitoring the breaker contact will ensure scheme stability. BRK 1 FLSHOVR DIFF V PKP GE Multilin L90 Line Current Differential System 5-265...
  • Page 396 BRK 1 FLSHOVR SPV A to BRK 1 FLSHOVR SPV C: These settings specify FlexLogic operands (per breaker pole) that supervise the operation of the element per phase. Supervision can be provided by operation of other protection 5-266 L90 Line Current Differential System GE Multilin...
  • Page 397 BRK 1 FLSHOVR DIFF V SRC: PKP: SRC 1 SRC 2 SRC 6 , … , , none ΔVA > PKP Δ VA = VA - Va 842018A2.CDR Figure 5–144: BREAKER FLASHOVER SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-267...
  • Page 398 A restrike event (FlexLogic operand) is declared if all of the following hold: • The current is initially interrupted. 5-268 L90 Line Current Differential System GE Multilin...
  • Page 399 “1” when breaker is opened, either manually or from protection logic. • BRK RSTR 1 CLS CMD: This setting assigns a FlexLogic operand indicating a breaker close command. It must be logic “1” when breaker is closed. GE Multilin L90 Line Current Differential System 5-269...
  • Page 400 Range: FlexLogic™ operand. To supervise voltage logic, CONT MONITOR V-SUPV: MESSAGE use VT FUSE FAIL OP Range: Self-reset, Latched, Disabled CONT MONITOR MESSAGE TARGET: Self-reset Range: Disabled, Enabled CONT MONITOR MESSAGE EVENTS: Disabled 5-270 L90 Line Current Differential System GE Multilin...
  • Page 401 SETTING CONT MONITOR V_SUPV: Off = 0 FLEXLOGIC OPERANDS CONT MONITOR OP CONT MONITOR PKP SETTING CONT MONITOR DPO CONT MONITOR V_OP: Off = 0 827049A3.vsd Figure 5–148: CONTINUOUS MONITOR SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-271...
  • Page 402 CT FAIL 3I0 INPUT 2 PICKUP: This setting selects the 3I_0 pickup value for input 2 (different CT input) of the relay. • CT FAIL 3V0 INPUT: This setting selects the voltage source. 5-272 L90 Line Current Differential System GE Multilin...
  • Page 403 CT FAIL 3IO INPUT2: CT FAIL 3IO INPUT2 PKP: SRC2 3IO > PICKUP SETTING SETTING CT FAIL 3VO INPUT: CT FAIL 3VO INPUT: SRC1 3VO > PICKUP 827048A6.CDR Figure 5–149: CT FAILURE DETECTOR SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-273...
  • Page 404 An additional condition is introduced to inhibit a fuse failure declaration when the monitored circuit is de-energized; positive- sequence voltage and current are both below threshold levels. The function setting enables and disables the fuse failure feature for each source. 5-274 L90 Line Current Differential System GE Multilin...
  • Page 405 SRC1 VT FUSE FAIL DPO FLEXLOGIC OPERA DS SRC1 50DD OP OPEN POLE OP The OPEN POLE OP operand is applicable to the D60, L60, and L90 onl . RESET Reset-dominant FLEXLOGIC OPERA D SRC1 VT FUSE FAIL VOL LOSS...
  • Page 406 This setting is relevant if open pole condition at the remote end of the line is to be sensed and utilized by the relay ( FlexLogic™ operand). OPEN POLE REM OP 5-276 L90 Line Current Differential System GE Multilin...
  • Page 407 When used in configuration with only one breaker, the should be BREAKER 2 FUNCTION “Enabled” and the setting should be “On” (refer to the Breaker Control section earlier in this chapter BREAKER 2 OUT OF SV for additional details). GE Multilin L90 Line Current Differential System 5-277...
  • Page 408 5.7 CONTROL ELEMENTS 5 SETTINGS Figure 5–151: OPEN POLE DETECTOR LOGIC (Sheet 1 of 2) 5-278 L90 Line Current Differential System GE Multilin...
  • Page 409 I_2 / I_1 ratio. The intention of this function is to detect a single-phase broken conductor only. As such two-phase or three-phase broken conductors cannot be detected. GE Multilin L90 Line Current Differential System 5-279...
  • Page 410 2 cyc | Ic’ | - | Ic | > 0.05pu Where I’ is 4 cycles old FLEXLOGIC OPERAND BROKEN CONDUCT 1 One phase current loss detection Figure 5–153: BROKEN CONDUCTOR DETECTION LOGIC 5-280 L90 Line Current Differential System GE Multilin...
  • Page 411 • = measured load RMS current before overload occurs. • k= IEC 255-8 k-factor applied to I , defining maximum permissible current above nominal current. • = protected element base (nominal) current. GE Multilin L90 Line Current Differential System 5-281...
  • Page 412 -------------- - (EQ 5.31) –   op In When current is less than the dropout level, I > 0.97 × k × I , the element starts decreasing the thermal energy: 5-282 L90 Line Current Differential System GE Multilin...
  • Page 413 30 minutes Busbar 60 minutes 20 minutes Underground cable 20 to 60 minutes 60 minutes The logic for the thermal overload protection element is shown below. Figure 5–155: THERMAL OVERLOAD PROTECTION SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-283...
  • Page 414: Pilot Schemes

    DUTT RX2: MESSAGE Range: FlexLogic operand DUTT RX3: MESSAGE Range: FlexLogic operand DUTT RX4: MESSAGE Range: Self-Reset, Latched, Disabled DUTT SCHEME TARGET: MESSAGE Self-Reset Range: Disabled, Enabled DUTT SCHEME EVENTS: MESSAGE Disabled 5-284 L90 Line Current Differential System GE Multilin...
  • Page 415 (often via different paths) and building appropriate security logic (such as series (AND gate) or 2-out-of-3 voting logic) with FlexLogic. The settings should be associated with the final DUTT RX1(4) (secure) TX signals. GE Multilin L90 Line Current Differential System 5-285...
  • Page 416 Off = 0 DUTT TRIP A Phase DUTT TRIP B TRIP TABLE Selector DUTT TRIP C DUTT TRIP 3P FLEXLOGIC OPERANDS AR FORCE 3P TRIP OPEN POLE OP 837012AD.CDR Figure 5–156: DUTT SCHEME LOGIC 5-286 L90 Line Current Differential System GE Multilin...
  • Page 417 The transmit codes and trip table of the PUTT scheme are identical as those for the direct under-reaching transfer trip scheme. Please refer to Chapter 8: Theory of Operation for more information. GE Multilin L90 Line Current Differential System 5-287...
  • Page 418 FLEXLOGIC OPERANDS GND DIST Z1 PKP PUTT TX1 PUTT TX2 Phase TRANSMIT TABLE Selector PUTT TX3 PUTT TX4 FLEXLOGIC OPERANDS AR FORCE 3P TRIP OPEN POLE OP 837013AD.CDR Figure 5–157: PUTT SCHEME LOGIC 5-288 L90 Line Current Differential System GE Multilin...
  • Page 419 Ground directional overcurrent functions available in the relay can be used in conjunction with the Zone 2 distance element to key the scheme and initiate its opera- tion. This provides increased coverage for high-resistance faults. GE Multilin L90 Line Current Differential System 5-289...
  • Page 420 This setting enables the relay to avoid a permanent lock- up of the transmit/receive loop. • ECHO LOCKOUT: This setting defines the lockout period for the echo logic after sending the echo pulse. 5-290 L90 Line Current Differential System GE Multilin...
  • Page 421 In two-bit applications, must be used. In four-bit applications, POTT RX1 POTT RX2 POTT RX1 , and must be used. POTT RX1 POTT RX2 POTT RX3 POTT RX4 GE Multilin L90 Line Current Differential System 5-291...
  • Page 422 Echo duration and lockout logic SETTI G ECHO TABLE POTT ECHO COND: Phase Custom Selector Off = 0 FLEXLOGIC OPERANDS AR FORCE 3P TRIP OPEN POLE OP 837014AH.C Figure 5–158: POTT SCHEME LOGIC 5-292 L90 Line Current Differential System GE Multilin...
  • Page 423 POTT1 RX2: MESSAGE Range: FlexLogic operand POTT1 RX3: MESSAGE Range: FlexLogic operand POTT1 RX4: MESSAGE Range: Self-Reset, Latched, Disabled POTT1 SCHEME TARGET: MESSAGE Self-Reset Range: Disabled, Enabled POTT1 SCHEME EVENTS: MESSAGE Disabled GE Multilin L90 Line Current Differential System 5-293...
  • Page 424 Negative-Sequence Directional IOC or Neutral Directional IOC. Both of these ele- ments have separate forward (FWD) and reverse (REV) output operands. The forward indication is used (NEG SEQ DIR OC1 FWD or NEUTRAL DIR OC1 FWD). Figure 5–159: POTT1 (GROUND) SCHEME LOGIC 5-294 L90 Line Current Differential System GE Multilin...
  • Page 425 Range: FlexLogic operand HYB POTT RX3: MESSAGE Range: FlexLogic operand HYB POTT RX4: MESSAGE Range: Self-Reset, Latched, Disabled HYB POTT SCHEME MESSAGE TARGET: Self-Reset Range: Disabled, Enabled HYB POTT EVENT: MESSAGE Disabled GE Multilin L90 Line Current Differential System 5-295...
  • Page 426 Generally, this scheme uses an overreaching zone 2 distance element to essentially compare the direction to a fault at all terminals of the line. Ground directional overcurrent functions available in the L90 can be used in conjunction with the zone 2 distance element to key the scheme and initiate operation.
  • Page 427 The transmit codes and trip table of the hybrid POTT scheme are the same as those for the permissive under-reaching transfer trip scheme. Please refer to the description of the PUTT scheme for more information. GE Multilin L90 Line Current Differential System 5-297...
  • Page 428 FLEXLOGIC OPERA DS PH DIST Z4 PKP AR FORCE 3P TRIP GND DIST Z4 PKP OPEN POLE OP 837015AL.CDR PH DIST Z1 PKP GND DIST Z1 PKP Figure 5–160: HYBRID POTT SCHEME LOGIC 5-298 L90 Line Current Differential System GE Multilin...
  • Page 429 If used by this scheme, the selected ground directional overcurrent functions must be enabled, config- ured, and programmed accordingly. In single-pole tripping applications, the scheme uses local fault type identification provided by the phase selector together with information received from the remote terminal. GE Multilin L90 Line Current Differential System 5-299...
  • Page 430 For greater security and to overcome GND DIR O/C REV spurious directional element operation during transients, adding at least 0.5 cycles of pickup delay to the forward direc- tional element is recommended. 5-300 L90 Line Current Differential System GE Multilin...
  • Page 431 In two-bit applications, BLOCK SCHEME RX1 BLOCK SCHEME RX1 must be used. In four-bit applications, BLOCK SCHEME RX2 BLOCK SCHEME RX1 BLOCK SCHEME RX2 BLOCK SCHEME , and must be used. BLOCK SCHEME RX4 GE Multilin L90 Line Current Differential System 5-301...
  • Page 432 GND DIST Z4 PKP DELAY: DIR BLOCK TX INIT TRANS BLOCK RESET DELAY: FLEXLOGIC OPERA DS PH DIST Z1 PKP GND DIST Z1 PKP 837016AF.CDR Figure 5–161: DIRECTIONAL COMPARISON BLOCKING SCHEME LOGIC 5-302 L90 Line Current Differential System GE Multilin...
  • Page 433 BITS: 1 Range: FlexLogic operand DCUB RX1: MESSAGE Range: FlexLogic operand DCUB LOG1: MESSAGE Range: FlexLogic operand DCUB RX2: MESSAGE Range: FlexLogic operand DCUB LOG2: MESSAGE Range: FlexLogic operand DCUB RX3: MESSAGE GE Multilin L90 Line Current Differential System 5-303...
  • Page 434 (for example, digital communication channels utilizing the L90 teleprotection input/outputs). To make the scheme fully operational as a stand-alone feature, the scheme output operands must be configured to inter- face with other relay functions, output contacts in particular.
  • Page 435 LINE END OPEN PICKUP DELAY: This setting defines the pickup value for validation of the line end open conditions as detected by the line pickup logic via the FlexLogic operand. The validated line end open con- LINE PICKUP LEO PKP GE Multilin L90 Line Current Differential System 5-305...
  • Page 436 In two-bit applications, with DCUB RX1 DCUB LOG1 DCUB RX1 DCUB LOG1 with must be used. In four-bit applications, all receive and loss-of-guard signals must be DCUB RX2 DCUB LOG2 used. 5-306 L90 Line Current Differential System GE Multilin...
  • Page 437 ECHO LOCKOUT: Off = 0 Echo duration/lockout logic FLEXLOGIC OPERANDS GND DIST Z4 PKP PHS DIST Z4 PKP GND DIST Z1 PKP PHS DIST Z1 PKP Figure 5–162: DIRECTIONAL COMPARISON UNBLOCKING SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-307...
  • Page 438: Autoreclose

    Range: 0.00 to 655.35 s in steps of 0.01 AR 3-P DEAD TIME 2: MESSAGE 1.20 s Range: 0.00 to 655.35 s in steps of 0.01 AR 3-P DEAD TIME 3: MESSAGE 2.00 s 5-308 L90 Line Current Differential System GE Multilin...
  • Page 439 Each of the four programs can be set to trigger up to four reclosing attempts. The second, third, and fourth attempts always perform three-pole reclosing and have independent dead time delays. GE Multilin L90 Line Current Differential System 5-309...
  • Page 440 If two or more shots AR 3P TD INIT AR 3-P DEAD TIME 2 are enabled, the second, third, and fourth shots are always three-phase and start the timers. AR 3-P DEAD TIME 2(4) 5-310 L90 Line Current Differential System GE Multilin...
  • Page 441 The Initiate signal will stop the transfer timer. After the 3-P dead time times out the Close Breaker 1 signal will close first breaker again GE Multilin L90 Line Current Differential System 5-311...
  • Page 442 Breaker 1 if is set to “Yes”. If set to “No” the scheme will be sent to AR TRANSFER 2 TO 1 Lockout by the incomplete sequence timer. 5-312 L90 Line Current Differential System GE Multilin...
  • Page 443 This delay must be longer than the slowest expected trip from any protection not blocked after GE Multilin L90 Line Current Differential System 5-313...
  • Page 444 If all con- CLOSE BKR1 CLOSE BKR2 ditions allowing a breaker closure are not satisfied when this time expires, the scheme goes to “Lockout”. The mini- 5-314 L90 Line Current Differential System GE Multilin...
  • Page 445 AR BUS FLT INIT: This setting is used in breaker-and-a-half applications to allow the autoreclose control function to perform reclosing with only one breaker previously opened by bus protection. For line faults, both breakers must open for the autoreclose reclosing cycles to take effect. GE Multilin L90 Line Current Differential System 5-315...
  • Page 446 However, a FlexLogic operand, AR MODE SWITCH FAIL, is asserted if either simultaneous multiple activa- tions are initiated, or a single activation is initiated but recloser is already in progress. 5-316 L90 Line Current Differential System GE Multilin...
  • Page 447 In addition, the current AR mode is available as FlexLogic Operands because AR Mode equals to 1, 2, 3, and 4 respec- tively so that it can be monitored and logged. GE Multilin L90 Line Current Differential System 5-317...
  • Page 448 5.7 CONTROL ELEMENTS 5 SETTINGS Figure 5–165: SINGLE-POLE AUTORECLOSE LOGIC (Sheet 2 of 3) 5-318 L90 Line Current Differential System GE Multilin...
  • Page 449 OFF = 0 FLEXLOGIC OPERAND BREAKER 1 ONE P OPEN FLEXLOGIC OPERAND BREAKER 2 ONE P OPEN BKR ONE POLE OPEN (To sheet 1) 827833AA.CDR Figure 5–166: SINGLE-POLE AUTORECLOSE LOGIC (Sheet 3 of 3) GE Multilin L90 Line Current Differential System 5-319...
  • Page 450 5.7 CONTROL ELEMENTS 5 SETTINGS Figure 5–167: EXAMPLE RECLOSING SEQUENCE 5-320 L90 Line Current Differential System GE Multilin...
  • Page 451 The DC input voltage is compared to a user-settable threshold. A new contact input state must be maintained for a user- settable debounce time in order for the L90 to validate the new contact state. In the figure below, the debounce time is set at 2.5 ms;...
  • Page 452: Inputs/outputs

    Event Records menu, make the following settings changes: "Breaker Closed (52b)" CONTACT INPUT H5A ID: "Enabled" CONTACT INPUT H5A EVENTS: Note that the 52b contact is closed when the breaker is open and open when the breaker is closed. 5-322 L90 Line Current Differential System GE Multilin...
  • Page 453: Virtual Inputs

    “Virtual Input 1 to OFF = 0” VIRTUAL INPUT 1 ID: (Flexlogic Operand) SETTING Virt Ip 1 VIRTUAL INPUT 1 TYPE: Latched Self - Reset 827080A2.CDR Figure 5–169: VIRTUAL INPUTS SCHEME LOGIC GE Multilin L90 Line Current Differential System 5-323...
  • Page 454: Contact Outputs

    The most dependable protection of the initiating contact is provided by directly measuring current in the tripping circuit, and using this parameter to control resetting of the initiating relay. This scheme is often called trip seal-in. This can be realized in the L90 using the FlexLogic operand to seal-in the contact output as follows: CONT OP 1 ION “Cont Op 1"...
  • Page 455 5.8 INPUTS/OUTPUTS The L90 latching output contacts are mechanically bi-stable and controlled by two separate (open and close) coils. As such they retain their position even if the relay is not powered up. The relay recognizes all latching output contact cards and pop- ulates the setting menu accordingly.
  • Page 456: Virtual Outputs

    Logic equations. Any change of state of a virtual output can be logged as an event if programmed to do so. For example, if Virtual Output 1 is the trip signal from FlexLogic and the trip relay is used to signal events, the settings would be programmed as follows: 5-326 L90 Line Current Differential System GE Multilin...
  • Page 457: Remote Devices

    32 “DNA” bit pairs that represent the state of two pre-defined events and 30 user-defined events. All remaining bit pairs are “UserSt” bit pairs, which are status bits representing user-definable events. The L90 implementation provides 32 of the 96 available UserSt bit pairs.
  • Page 458: Remote Inputs

    5 SETTINGS c) LOCAL DEVICES: DEVICE ID FOR TRANSMITTING GSSE MESSAGES In a L90 relay, the device ID that represents the IEC 61850 GOOSE application ID (GoID) name string sent as part of each GOOSE message is programmed in the ...
  • Page 459: Remote Double-point Status Inputs

    The above operand setting represents a specific DNA function (as shown in the following table) to be transmitted. Table 5–28: IEC 61850 DNA ASSIGNMENTS IEC 61850 DEFINITION FLEXLOGIC OPERAND Test IEC 61850 TEST MODE ConfRev IEC 61850 CONF REV GE Multilin L90 Line Current Differential System 5-329...
  • Page 460: Direct Inputs/outputs

    DIRECT INPUT 1-2 MESSAGE DEFAULT: Off  Range: Off, On DIRECT INPUT 1-8 MESSAGE DEFAULT: Off Range: Off, On DIRECT INPUT 2-1 MESSAGE DEFAULT: Off Range: Off, On DIRECT INPUT 2-2 MESSAGE DEFAULT: Off 5-330 L90 Line Current Differential System GE Multilin...
  • Page 461 L90 communication channel (same for 1-2...1-8) (87L is Enabled) SETTING DIRECT OUTPUT 1-1: FLEXLOGIC OPERAND (same for 1-2...1-8) Fail DIRECT I/P 1-1 Off (Flexlogic Operand) (same for 1-2...1-8) 831024A1.CDR Figure 5–170: DIRECT INPUTS/OUTPUTS LOGIC GE Multilin L90 Line Current Differential System 5-331...
  • Page 462: Resetting

    GOOSE ANALOG 1 PU: This setting specifies the per-unit base factor when using the GOOSE analog input FlexAna- log values in other L90 features, such as FlexElements. The base factor is applied to the GOOSE analog input FlexAn- alog quantity to normalize it to a per-unit quantity. The base units are described in the following table.
  • Page 463: Iec 61850 Goose Integers

    = maximum primary RMS value of all the sources related to the +IN and –IN inputs BASE (Max Delta Volts) The GOOSE analog input FlexAnalog values are available for use in other L90 functions that use FlexAnalog values. 5.8.12 IEC 61850 GOOSE INTEGERS ...
  • Page 464: Transducer Inputs And Outputs

    –20 to +180 MW; in this case the value would be “–20” and the DCMA INPUT H1 MIN VALUE DCMA INPUT H1 MAX value “180”. Intermediate values between the min and max values are scaled linearly. VALUE 5-334 L90 Line Current Differential System GE Multilin...
  • Page 465: Rtd Inputs

    1.5 pu. FlexElement operands are available to FlexLogic for further interlocking or to operate an output contact directly. Refer to the following table for reference temperature values for each RTD type. GE Multilin L90 Line Current Differential System 5-335...
  • Page 466 168.47 280.77 233.97 16.00 172.46 291.96 243.30 16.39 175.84 303.46 252.88 16.78 179.51 315.31 262.76 17.17 183.17 327.54 272.94 17.56 186.82 340.14 283.45 17.95 190.45 353.14 294.28 18.34 194.08 366.53 305.44 18.73 5-336 L90 Line Current Differential System GE Multilin...
  • Page 467: Dcma Outputs

    – MAX VAL MIN VAL MAX VAL < 0.1 pu. The resulting characteristic is illustrated in the following figure. DRIVING SIGNAL MIN VAL MAX VAL 842739A1.CDR Figure 5–171: DCMA OUTPUT CHARACTERISTIC GE Multilin L90 Line Current Differential System 5-337...
  • Page 468 The CT ratio is 5000:5 and the maximum load current is 4200 A. The current should be monitored from 0 A upwards, allow- ing for 50% overload. The phase current with the 50% overload margin is: 5-338 L90 Line Current Differential System GE Multilin...
  • Page 469 1.27 kV – • ±0.5% of reading For example, under nominal conditions, the positive-sequence reads 230.94 kV and the worst-case error is 0.005 x 230.94 kV + 1.27 kV = 2.42 kV. GE Multilin L90 Line Current Differential System 5-339...
  • Page 470: Testing

    TEST MODE FORCING: MESSAGE The L90 provides a test facility to verify the functionality of contact inputs and outputs, some communication channels and the phasor measurement unit (where applicable), using simulated conditions. The test mode is indicated on the relay face- plate by a Test Mode LED indicator.
  • Page 471: Force Contact Inputs

    Following a restart, power up, settings TEST MODE FUNCTION upload, or firmware upgrade, the test mode will remain at the last programmed value. This allows a L90 that has been placed in isolated mode to remain isolated during testing and maintenance activities. On restart, the TEST MODE FORCING setting and the force contact input and force contact output settings all revert to their default states.
  • Page 472: Force Contact Outputs

    PUSHBUTTON 1 FUNCTION input 1 to initiate the Test mode, make the following changes in the menu:   SETTINGS TESTING TEST MODE “Enabled” and “ ” TEST MODE FUNCTION: TEST MODE INITIATE: 5-342 L90 Line Current Differential System GE Multilin...
  • Page 473: Channel Tests

    Range: 0.000 to 9.999 kA in steps of 0.001 PMU 1 IA TEST MESSAGE MAGNITUDE: 1.000 kA Range: –180.00 to 180.00° in steps of 0.05 PMU 1 IA TEST MESSAGE ANGLE: –10.00° GE Multilin L90 Line Current Differential System 5-343...
  • Page 474 In test mode, the following actions take place: a. The Data Invalid / Test Mode bit (bit 15 in the STAT word) is set. b. The Sim bit in all output datasets is set. 5-344 L90 Line Current Differential System GE Multilin...
  • Page 475: Actual Values

     COMM STATUS See page 6-10.  REMAINING CONNECT  ACTUAL VALUES  87L DIFFERENTIAL See page 6-14.  METERING  CURRENT  SOURCE SRC 1 See page 6-15.   SOURCE SRC 2  GE Multilin L90 Line Current Differential System...
  • Page 476  PMU RECORDS See page 6-25.   MAINTENANCE See page 6-26.   ACTUAL VALUES  MODEL INFORMATION See page 6-27.  PRODUCT INFO   FIRMWARE REVISIONS See page 6-27.  L90 Line Current Differential System GE Multilin...
  • Page 477 The state displayed will be that of the remote point unless the remote device has been established to be “Offline” in which case the value shown is the programmed default state for the remote input. GE Multilin L90 Line Current Differential System...
  • Page 478: Remote Double-point Status Inputs

    Range: On, Off, VOff, VOn, IOn, IOff  CONTACT OUTPUTS Cont Op 1  Range: On, Off, VOff, VOn, IOn, IOff Cont Op 2 MESSAGE  Range: On, Off, VOff, VOn, IOn, IOff Cont Op xx MESSAGE L90 Line Current Differential System GE Multilin...
  • Page 479: Virtual Outputs

    The present state of the programmed remote devices is shown here. The message indicates ALL REMOTE DEVICES ONLINE whether or not all programmed remote devices are online. If the corresponding state is "No", then at least one required remote device is not online. GE Multilin L90 Line Current Differential System...
  • Page 480: Channel Tests

    Range: n/a, FAIL, OK VALIDITY OF CHANNEL MESSAGE CONFIGURATION: n/a Range: n/a, FAIL, OK PFLL MESSAGE STATUS: n/a The status information for two channels is shown here. A brief description of each actual value is below: L90 Line Current Differential System GE Multilin...
  • Page 481: Digital Counters

      PATH: ACTUAL VALUES STATUS SELECTOR SWITCHES Range: Current Position / 7  SELECTOR SWITCHES SELECTOR SWITCH 1  POSITION: 0/7 Range: Current Position / 7 SELECTOR SWITCH 2 MESSAGE POSITION: 0/7 GE Multilin L90 Line Current Differential System...
  • Page 482: Flex States

    The RTC Sync Source actual value is the time synchronizing source the relay is using at present. Possible sources are: Port 1 PTP Clock, Port 2 PTP Clock, Port 3 PTP Clock, IRIG-B, SNTP, and None. L90 Line Current Differential System GE Multilin...
  • Page 483: Iec 61850 Goose Integers

    UINT INPUT 16 MESSAGE The L90 Line Current Differential System is provided with optional IEC 61850 communications capability. This feature is specified as a software option at the time of ordering. Refer to the Ordering section of chap- ter 2 for additional details.
  • Page 484: Remaining Connection Status

    Range: 0 to 4 MODBUS TCP (max 4) MESSAGE Range: 0 to 2 DNP (max 2) MESSAGE Range: 0 to 2 IEC-104 (max 2) MESSAGE Range: 0 to 4 PMU TCP (max 4) MESSAGE 6-10 L90 Line Current Differential System GE Multilin...
  • Page 485: Metering Conventions

    WATTS = Negative VARS = Positive PF = Lead PF = Lag PF = Lead Current UR RELAY 827239AC.CDR S=VI Generator Figure 6–1: FLOW DIRECTION OF SIGNED VALUES FOR WATTS AND VARS GE Multilin L90 Line Current Differential System 6-11...
  • Page 486 -- - V   -- - V   -- - V   -- - V   -- - V   The above equations apply to currents as well. 6-12 L90 Line Current Differential System GE Multilin...
  • Page 487 The power system voltages are phase-referenced – for simplicity – to VAG and VAB, respectively. This, however, is a relative matter. It is important to remember that the L90 displays are always referenced as specified under SETTINGS ...
  • Page 488: Differential Current

    The metered current values are displayed for all line terminals in fundamental phasor form. All angles are shown with respect to the reference common for all L90 devices; that is, frequency, source currents, and voltages. The metered pri- mary differential and restraint currents are displayed for the local relay.
  • Page 489: Sources

    RMS In: MESSAGE 0.000 SRC 1 PHASOR Ia: MESSAGE 0.000 0.0° SRC 1 PHASOR Ib: MESSAGE 0.000 0.0° SRC 1 PHASOR Ic: MESSAGE 0.000 0.0° SRC 1 PHASOR In: MESSAGE 0.000 0.0° GE Multilin L90 Line Current Differential System 6-15...
  • Page 490 SRC 1 RMS Vab: MESSAGE 0.00 SRC 1 RMS Vbc: MESSAGE 0.00 SRC 1 RMS Vca: MESSAGE 0.00 SRC 1 PHASOR Vab: MESSAGE 0.000 0.0° SRC 1 PHASOR Vbc: MESSAGE 0.000 0.0° 6-16 L90 Line Current Differential System GE Multilin...
  • Page 491 REACTIVE PWR MESSAGE b: 0.000 SRC 1 REACTIVE PWR MESSAGE c: 0.000 SRC 1 APPARENT PWR MESSAGE 3: 0.000 SRC 1 APPARENT PWR MESSAGE a: 0.000 SRC 1 APPARENT PWR MESSAGE b: 0.000 GE Multilin L90 Line Current Differential System 6-17...
  • Page 492 DMD IA DATE: MESSAGE 2001/07/31 16:30:07 SRC 1 DMD IB: MESSAGE 0.000 SRC 1 DMD IB MAX: MESSAGE 0.000 SRC 1 DMD IB DATE: MESSAGE 2001/07/31 16:30:07 SRC 1 DMD IC: MESSAGE 0.000 6-18 L90 Line Current Differential System GE Multilin...
  • Page 493 If the 87L function is enabled, then dedicated 87L frequency tracking is engaged. In this case, the relay uses the METERING   value for all computations, overriding the value. TRACKING FREQUENCY TRACKING FREQUENCY SOURCE FREQUENCY GE Multilin L90 Line Current Differential System 6-19...
  • Page 494: Sensitive Directional Power

    FREQUENCY RATE OF MESSAGE CHANGE 3: 0.00 Hz/s FREQUENCY RATE OF MESSAGE CHANGE 4: 0.00 Hz/s The metered frequency rate of change for the frequency rate of change elements is shown here. 6-20 L90 Line Current Differential System GE Multilin...
  • Page 495: Flexelements

    MESSAGE 0.000 The L90 Line Current Differential System is provided with optional IEC 61850 communications capability. This feature is specified as a software option at the time of ordering. Refer to the Ordering section of chap- ter 2 for additional details.
  • Page 496: Wattmetric Ground Fault

    PMU 1 I1: MESSAGE 0.0000 kA, 0.00° PMU 1 I2: MESSAGE 0.0000 kA, 0.00° PMU 1 I0: MESSAGE 0.0000 kA, 0.00° PMU 1 FREQUENCY: MESSAGE 0.0000 Hz PMU 1 df/dt: MESSAGE 0.0000 Hz/s 6-22 L90 Line Current Differential System GE Multilin...
  • Page 497: Transducer Inputs And Outputs

    RTD INPUT xx  -50 °C Actual values for each RTD input channel that is enabled are displayed with the top line as the programmed channel ID and the bottom line as the value. GE Multilin L90 Line Current Differential System 6-23...
  • Page 498: Records

    If all 1024 event records have been filled, the oldest record will be removed as a new record is added. Each event record shows the event identifier/sequence number, cause, and date/time stamp associated with the event trigger. Refer to the  menu for clearing event records. COMMANDS CLEAR RECORDS 6-24 L90 Line Current Differential System GE Multilin...
  • Page 499: Oscillography

     RECORDING The number of triggers applicable to the phasor measurement unit recorder is indicated by the value. NUMBER OF TRIGGERS The status of the phasor measurement unit recorder is indicated as follows: GE Multilin L90 Line Current Differential System 6-25...
  • Page 500: Breaker Maintenance

    BKR 1 ARCING AMP  menu for clearing breaker arcing current records. The COMMANDS CLEAR RECORDS BREAKER OPERATING TIME defined as the slowest operating time of breaker poles that were initiated to open. 6-26 L90 Line Current Differential System GE Multilin...
  • Page 501: Product Information

    6.5PRODUCT INFORMATION 6.5.1 MODEL INFORMATION   PATH: ACTUAL VALUES PRODUCT INFO MODEL INFORMATION Range: standard GE Multilin order code format;  MODEL INFORMATION ORDER CODE LINE 1: example order code shown  L90-E00-HCH-F8F-H6A Range: standard GE Multilin order code format...
  • Page 502 6.5 PRODUCT INFORMATION 6 ACTUAL VALUES 6-28 L90 Line Current Differential System GE Multilin...
  • Page 503: Commands And

    The states of up to 64 virtual inputs are changed here. The first line of the display indicates the ID of the virtual input. The second line indicates the current or selected status of the virtual input. This status will be a state off (logic 0) or on (logic 1). GE Multilin L90 Line Current Differential System...
  • Page 504: Clear Records

    The complete date, as a minimum, must be entered to allow execution of this command. The new time (if entered) and date will take effect at the moment the ENTER key is clicked. The timescale of the entered time should be local time, including daylight time where and when applicable. L90 Line Current Differential System GE Multilin...
  • Page 505: Relay Maintenance

    Various self-checking diagnostics are performed in the background while the L90 is running, and diagnostic information is stored on the non-volatile memory from time to time based on the self-checking result. Although the diagnostic information is cleared before the L90 is shipped from the factory, the user may want to clear the diagnostic information for themselves under certain circumstances.
  • Page 506 PMU and not to the absolute UTC time. Therefore a simple IRIG-B genera- tor could be used instead. Also, the test set does not have to support GPS synchronization. Any stable signal source can L90 Line Current Differential System GE Multilin...
  • Page 507: Security

    Operator Logoff: Selecting ‘Yes’ allows the Supervisor to forcefully logoff an operator session. • Clear Security Data: Selecting ‘Yes’ allows the Supervisor to forcefully clear all the security logs and clears all the operands associated with the self-tests. GE Multilin L90 Line Current Differential System...
  • Page 508: Targets Menu

    The critical fail relay on the power supply module is de-energized. • All other output relays are de-energized and are prevented from further operation. • The faceplate In Service LED indicator is turned off. • event is recorded. RELAY OUT OF SERVICE L90 Line Current Differential System GE Multilin...
  • Page 509 Contact Factory (xxx) • Latched target message: Yes. • Description of problem: One or more installed hardware modules is not compatible with the L90 order code. • How often the test is performed: Module dependent. • What to do: Contact the factory and supply the failure code noted in the display. The “xxx” text identifies the failed mod- ule (for example, F8L).
  • Page 510 • What to do: Verify that all the items in the GOOSE data set are supported by the L90. The EnerVista UR Setup soft- ware will list the valid items. An IEC61850 client will also show which nodes are available for the L90.
  • Page 511 How often the test is performed: Upon initiation of a contact output state change. • What to do: Verify the state of the output contact and contact the factory if the problem persists. GE Multilin L90 Line Current Differential System...
  • Page 512 Description of problem: The ambient temperature is greater than the maximum operating temperature (+80°C). • How often the test is performed: Every hour. • What to do: Remove the L90 from service and install in a location that meets operating temperature standards. UNEXPECTED RESTART: Press “RESET” key •...
  • Page 513 Brick. Where multiple UR-series devices have self-test errors, look for common causes. GE Multilin L90 Line Current Differential System 7-11...
  • Page 514 Brick output failing to respond to an output command can only be detected while the command is active, and so in this case the target is latched. A latched target can be unlatched by pressing the faceplate reset key if the command has ended, however the output may still be non-functional. 7-12 L90 Line Current Differential System GE Multilin...
  • Page 515: Security

    To add user accounts: Select the Security > User Management menu item to open the user management window. Enter a username in the User field. The username must be 4 to 20 characters in length. GE Multilin L90 Line Current Differential System...
  • Page 516: Modifying User Privileges

    The EnerVista security management system must be enabled To modify user privileges: Select the Security > User Management menu item to open the user management window. Locate the username in the User field. L90 Line Current Differential System GE Multilin...
  • Page 517 The user is not granted write access to functions that are not checked, even if the Update Info field is checked. Admin The user is an EnerVista UR Setup administrator, therefore receiving all of the administrative rights. Exercise caution when granting administrator rights. Click OK to save the changes. GE Multilin L90 Line Current Differential System...
  • Page 518: Cybersentry

    (Administrator, Engineer, Supervisor, Observer, Operator) as login names and the associated passwords are stored on the UR device. As such, when using the local accounts, access is not user-attributable. L90 Line Current Differential System GE Multilin...
  • Page 519 > Product Setup > Security, accessible from the top-level menu. NOTE No password or security information are displayed in plain text by the EnerVista software or UR device, nor are they ever transmitted without cryptographic protection. GE Multilin L90 Line Current Differential System...
  • Page 520: Security Menu

    This setting must following (Shared) Secret meet the CyberSentry password password requirements. section for requirements RADIUS Authentication method used by RADIUS EAP-TTLS EAP-TTLS EAP-TTLS Administrator Authentication server. Currently fixed to EAP-TTLS. Method L90 Line Current Differential System GE Multilin...
  • Page 521 Change Text The specified role protected. All RADIUS users are password- following following Me1# and Administrator, protected. password password except for section for section for Supervisor, where requirements requireme it is only itself GE Multilin L90 Line Current Differential System...
  • Page 522 |--------------- Supervisory see table notes see table notes |--------------- Display Properties Clear relay records |--------------- (settings) |--------------- Communications |--------------- Modbus user map |--------------- Real Time Clock |--------------- Oscillography |--------------- Data Logger |--------------- Demand L90 Line Current Differential System GE Multilin...
  • Page 523 |--------------- Analogs IEC61850 GOOSE |--------------- Integers |------------ Transducer I/O |------------ Testing |------------ Front Panel Labels Designer |------------ Protection Summary Commands |------------ Virtual Inputs |------------ Clear Records |------------ Set date and time User Displays GE Multilin L90 Line Current Differential System...
  • Page 524 Remote user IDs must reside on an external RADIUS server, and must be provided with the requisite user role (see the fol- lowing example). Users are specified in the RADIUS server configuration file for users. Roles are specified in the RADIUS server dictionary. Example: In the file ‘users’: exampleusername User-Password == "examplepassword" 8-10 L90 Line Current Differential System GE Multilin...
  • Page 525: Theory Of Operation

    The second major technical consideration is the restraint characteristic, which is the decision boundary between situations that are declared to be a fault and those that are not. The L90 uses an innovative adaptive decision process based on an on-line computation of the sources of measurement error. In this adaptive approach, the restraint region is an ellipse with variable major axis, minor axis, and orientation.
  • Page 526: Removal Of Decaying Offset

    Since the sampling clocks are synchronized, the time stamp is simply a sequence number. L90 Line Current Differential System GE Multilin...
  • Page 527: Disturbance Detection

    CT saturation is detected (see CT Saturation Detection for details); is an adaptive restraint term (see Online Estimate Of Measurement Error for details) LOC_ADA_A The squared restraining current is calculated as a sum of squared local and all remote restraints: GE Multilin L90 Line Current Differential System...
  • Page 528: Ground Differential Element

    The line ground differential function allows sensitive ground protection for single-line to-ground faults, allowing the phase differential element to be set higher (above load) to provide protection for multi-phase faults. The L90 ground differential function calculates ground differential current from all terminal phase currents. The maximum phase current is used for the restraint.
  • Page 529: Clock Synchronization

    In all cases, an estimate of phase error is computed and used to automatically adapt the restraint region to compensate. Frequency tracking is provided that will accommodate any fre- quency shift normally encountered in power systems. GE Multilin L90 Line Current Differential System...
  • Page 530: Frequency Tracking And Phase Locking

    GPS (Global Positioning System) to compensate for the channel delay asymmetry. This feature requires a GPS receiver to provide a GPS clock signal to the L90. With this option there are two clocks as each terminal: a local sampling clock and a local GPS clock.
  • Page 531: Frequency Detection

    Current measurements can generally provide the most accurate information, but are not always available and may contain large errors during faults or switching transients. Time stamped messages are GE Multilin L90 Line Current Differential System...
  • Page 532 256 to the round trip and add 128 to the phase angle. Also, if the above equations are computed using integer values of time stamps, a conversion to phase angle in radians is required by multiplying by  / 32. L90 Line Current Differential System GE Multilin...
  • Page 533 ( T1 T2 T2 T1 ) i -3, i-2, i -1, δ θ Calculate 1, 1. Speed up Slow down 831729A2.CDR Figure 9–2: ROUND TRIP DELAY AND CLOCK OFFSET COMPUTATION FROM TIME STAMPS GE Multilin L90 Line Current Differential System...
  • Page 534: Phase Locking Filter

    T = the time between execution of the filter algorithm repeat = time constant for the primary phase locked loop phase = time constant for the frequency locked loop frequency 9-10 L90 Line Current Differential System GE Multilin...
  • Page 535: Matching Phaselets

    A 6 Mhz clock with a 16-bit hardware counter is adequate, provided the method is used for achieving the 32-bit resolu- tion that is described in this document. • An 8-bit time stamp is adequate provided time stamp messages are exchanged once per cycle. • A 4-bit message sequence number is adequate. GE Multilin L90 Line Current Differential System 9-11...
  • Page 536: Online Estimate Of Measurement Errors

    1_A k   1_ADA_A 1_MAG_A Another source of the measurement errors is clock synchronization error, resulting in a clock uncertainty term. The L90 algorithm accounts for two terms of synchronization error corresponding to: • Raw clock deviation computed from time stamps. There are several effects that cause it to not track exactly. First, the ping-pong algorithm inherently produces slightly different estimates of clock deviation at each terminal.
  • Page 537: Ct Saturation Detection

    For short transmission lines the charging current is a small factor and can therefore be treated as an unknown error. In this application the L90 can be deployed with- out voltage sensors and the line charging current is included as a constant term in the total variance, increasing the differ- ential restraint current.
  • Page 538: Differential Element Characteristics

    The L90 incorporates an adaptive differential algorithm based on the traditional percent differential principle. In the tradi- tional percent differential scheme, the operating parameter is based on the phasor sum of currents in the zone and the restraint parameter is based on the scalar (or average scalar) sum of the currents in the protected zone - when the operat- ing parameter divided by the restraint parameter is above the slope setting, the relay will operate.
  • Page 539: Relay Synchronization

    9.1 OVERVIEW The major difference between the L90 differential scheme and a percent differential scheme is the use of an estimate of errors in the input currents to increase the restraint parameter during faults, permitting the use of more sensitive settings than those used in the traditional scheme.
  • Page 540: Operating Condition Characteristics

    9.2OPERATING CONDITION CHARACTERISTICS 9.2.1 DESCRIPTION Characteristics of differential elements can be shown in the complex plane. The operating characteristics of the L90 are fundamentally dependant on the relative ratios of the local and remote current phasor magnitudes and the angles of as shown in the Restraint Characteristics figure.
  • Page 541 9 THEORY OF OPERATION 9.2 OPERATING CONDITION CHARACTERISTICS Figure 9–7: RESTRAINT CHARACTERISTICS GE Multilin L90 Line Current Differential System 9-17...
  • Page 542: Trip Decision Example

    Current differential section of chapter 5. The following figure shows how the L90 settings affect the restraint characteristics. The local and remote currents are 180° apart, which represents an external fault. The breakpoint between the two slopes indicates the point where the restraint area is becoming wider to override uncertainties from CT saturation, fault noise, harmonics, etc.
  • Page 543 9 THEORY OF OPERATION 9.2 OPERATING CONDITION CHARACTERISTICS loc pu OPERATE RESTRAINT BP=8, P=2, S1=30%, S2=50% BP=4, P=1, S1=30%, S2=50% BP=4, P=1, S1=20%, S2=40% OPERATE rem pu 831725A1.CDR Figure 9–8: SETTINGS IMPACT ON RESTRAINT CHARACTERISTIC GE Multilin L90 Line Current Differential System 9-19...
  • Page 544: Distance Elements

    (SIRs). The filter controls underestimation of the fault voltage magnitude to less than 1% of the nominal and prevents cer- tain phase angle anomalies that can be encountered under heavy CVT noise and high SIRs. 9-20 L90 Line Current Differential System GE Multilin...
  • Page 545: Distance Characteristics

    The limit angle of the comparator is adjustable enabling the user to shape the characteristic as a mho or a lens as shown in the figures below.The memory-polarized mho characteristic has an excellent directional integrity built-in as explained in the Memory polarization section. GE Multilin L90 Line Current Differential System 9-21...
  • Page 546 B ground element: I j  Z + I_0  K0  Z + I  K0M  Z – V (j  I_0 or j  I_2C)  e • C ground element: I 9-22 L90 Line Current Differential System GE Multilin...
  • Page 547 + I_0  K0  Z  K0M  Z  Z + I_0  K0  Z  K0M  Z C ground element: – V The blinders apply to the Quad characteristic only. GE Multilin L90 Line Current Differential System 9-23...
  • Page 548 COMP LIMIT I  Z Directional V_1M DIR COMP LIMIT I  Z I  Z Right Blinder – V 90° I  Z I  Z Left Blinder – V 90° 9-24 L90 Line Current Differential System GE Multilin...
  • Page 549: Memory Polarization

    The memory-polarized mho has an extra directional integrity built-in as illustrated below. The self-polarized mho character- istic is shifted in the reverse direction for a forward fault by an amount proportional to the source impedance, and in the for- ward direction for a reverse fault. GE Multilin L90 Line Current Differential System 9-25...
  • Page 550: Distance Elements Analysis

    Mutual zero-sequence compensation may raise concerns regarding directional integrity on reverse faults in the situation when the relay gets ‘overcompensated’. This problem does not affect the L90 because its ground distance elements use zero-sequence and negative-sequence currents in extra directional comparators. Both the currents are from the protected line and are not affected by any compensation as the latter applies only to the reach defining comparators: the mho, reac- tance and blinder characteristics.
  • Page 551 Zero-sequence directional difference angle = | 19.8° – 0.0° | = 19.8°  75° • Negative-sequence directional difference angle = | 19.8° – 0.0° | = 19.8°  75° • Fault-type comparator difference angle = | 19.8° – 19.8° | = 0.0°  50° • GE Multilin L90 Line Current Differential System 9-27...
  • Page 552 = 1.37 V 19.8°  Z + I_0  K0  Z  K0M  Z = 87.6 V –109.2° – V  Z + I_0  K0  Z = 91.5 V –93.0° 9-28 L90 Line Current Differential System GE Multilin...
  • Page 553 Fault-type comparator difference angle = | 19.8° – 19.8° | = 0.0°  50° • All six comparators and the overcurrent supervision are satisfied. The Quad Phase A ground element will operate for this fault. GE Multilin L90 Line Current Differential System 9-29...
  • Page 554: Phase Distance Applied To Power Transformers

    The L90 provides for any location of the VTs and CTs with respect to the involved power transformer and the direction of any given zone.
  • Page 555 ------ - 2I BC_21P BC_21P   ------ - 2I CA_21P CA_21P   ------ - I AB_21P AB_21P   ------ - I BC_21P BC_21P   ------ - I CA_21P CA_21P GE Multilin L90 Line Current Differential System 9-31...
  • Page 556: Example

    Normally, in order to respond to the fault shown in the figure, a distance relay shall be applied at the relaying point X. The relay input signals at this location are shown in the following table. 9-32 L90 Line Current Differential System GE Multilin...
  • Page 557 X, the relay shall be set to 0.687  85° secondary in order to reach to the fault shown in the figure. When installed at H, the relay shall be set to 2.569  88.4° to ensure exactly same coverage. See Chapter 9: Application of Settings for more information on setting calculations. GE Multilin L90 Line Current Differential System 9-33...
  • Page 558: Single-pole Tripping

    Initiate breaker failure protection for phases A, B and C, either individually or as a group. • Notify the open pole detector when a single pole operation is imminent. • Initiate either single or three pole reclosing. 9-34 L90 Line Current Differential System GE Multilin...
  • Page 559 If the fault was permanent appropriate protection elements would detect it and place a trip request for the trip output ele- ment. As the is still asserted, the request is executed as a three-pole trip. AR FORCE 3-P TRIP GE Multilin L90 Line Current Differential System 9-35...
  • Page 560 The response of the system from this point is as described above for the second trip, except the recloser will go to lockout upon the next initiation (depending on the number of shots programmed). 9-36 L90 Line Current Differential System GE Multilin...
  • Page 561: Phase Selection

    9.5 SINGLE-POLE TRIPPING 9.5.2 PHASE SELECTION The L90 uses phase relations between current symmetrical components for phase selection. First, the algorithm validates if there is enough zero-sequence, positive-sequence, and negative-sequence currents for reliable analysis. The comparison is adaptive; that is, the magnitudes of the three symmetrical components used mutually as restraints confirm if a given com- ponent is large enough to be used for phase selection.
  • Page 562: Communications Channels For Pilot-aided Schemes

    DESCRIPTION In the L90 relay pilot-aided schemes transmit a code representing the type of fault determined by the local phase selector according to the scheme logic. At a receiving terminal the local and remote data is combined to determine the action to be performed.
  • Page 563 BIT PATTERN RECEIVED REMOTE DETERMINATION LOCAL DETERMINATION OF TRIP OUTPUT OF FAULT TYPE FAULT TYPE AG Fault Trip Phase A (A+N/G) BG Fault Trip Phase B (B+N/G) CG Fault Trip Phase C (C+N/G) GE Multilin L90 Line Current Differential System 9-39...
  • Page 564 Table 9–18: BLOCKING SCHEME TRANSMIT CODES FOR 2-BIT CHANNELS PHASE SELECTOR DETERMINATION BIT PATTERN TRANSMITTED FLEXLOGIC™ OPERANDS OF FAULT TYPE ASSERTED TX1 STOP TX2 STOP AG, BC, BCG BG, CA, CAG CG, AB, ABG, 3P CG, AB, ABG, 3P, Unrecognized 9-40 L90 Line Current Differential System GE Multilin...
  • Page 565 DIR BLOCK TRIP C AG, BC, BCG BG, CA, CAG CG, AB, ABG, 3P, Unrecognized AB, ABG, 3P, Unrecognized DIR BLOCK TRIP 3P AG, BC, BCG BC, BCG Unrecognized BG, CA, CAG CA, CAG Unrecognized GE Multilin L90 Line Current Differential System 9-41...
  • Page 566 The TX1, TX2, TX3, TX4, RX1, RX2, RX3 and RX4 operands are used. Table 9–23: PERMISSIVE SCHEME TRANSMIT CODES FOR 4-BIT CHANNELS PHASE SELECTOR BIT PATTERN TRANSMITTED DETERMINATION OF FAULT TYPE AB, ABG, BC, BCG, CA, CAG, 3P, Unrecognized 9-42 L90 Line Current Differential System GE Multilin...
  • Page 567 BG, AB, ABG, BC, BCG, 3P, Trip Phase B Unrecognized MULTI-P CG, BC, BCG, CA, CAG, 3P, Trip Phase C Unrecognized MULTI-P BC, BCG Trip Three Phases CA, CAG AB, ABG MULTI-P Unrecognized GE Multilin L90 Line Current Differential System 9-43...
  • Page 568 BG, AB, ABG, BC, BCG, 3P, DIR BLOCK TRIP B Unrecognized MULTI-P CG, BC, BCG, CA, CAG, 3P, DIR BLOCK TRIP C Unrecognized MULTI-P BC, BCG DIR BLOCK TRIP 3P CA, CAG AB, ABG MULTI-P Unrecognized 9-44 L90 Line Current Differential System GE Multilin...
  • Page 569 AG, AB, ABG, CA, DCUB TRIP B CAG, 3P, unrecognized MULTI-P CG, BC, BCG, CA, DCUB TRIP C CAG, 3P, unrecognized MULTI-P BC, BCG DCUB TRIP 3P CA, CAG AB, ABG MULTI-P 3P or unrecognized GE Multilin L90 Line Current Differential System 9-45...
  • Page 570: Permissive Echo Signaling

    For the directional comparison unblocking scheme, the echo is performed in the same manner as the Hybrid POTT echo, but by applying additionally the following logic for both the Rx (received) and LOG (loss-of-guard) for each channel: ECHO = LOG AND RX NOTE 9-46 L90 Line Current Differential System GE Multilin...
  • Page 571: Pilot Scheme / Phase Selector Coordination

    In other cases, it is not recommended to delay the local trip decision. GE Multilin L90 Line Current Differential System 9-47...
  • Page 572: Cross-country Fault Example

    9.5.6 CROSS-COUNTRY FAULT EXAMPLE Assume a single pole operation application where L90 relays are used to protect a two terminal line, (terminals T1 and T2) using phase and ground distance zone 1, 2 and 3 elements in a permissive over-reaching transfer trip scheme. The perfor- mance of the system with one- two and four-bit communications channels is outlined for a mid-line phase A-to-ground fault and a co-incident phase B-to-ground fault just behind terminal T2.
  • Page 573: Overview

    9 THEORY OF OPERATION 9.6 FAULT LOCATOR 9.6FAULT LOCATOR 9.6.1 OVERVIEW The L90 uses two methods to determine fault type and fault location • A multi-ended fault location algorithm using synchronized currents and voltage measurements from all line terminals. •...
  • Page 574 A similar set of equations is applied to determine whether the fault is between the tap and the local terminal or between the tap and remote terminal 1. Next, having all the data prepared, the following universal equation is used to calculate the fault location. 9-50 L90 Line Current Differential System GE Multilin...
  • Page 575 RELAY 2 TO TAP RELAY 3 TO TAP 21.29  80.5° 36.50  80.5° 16.73  80.5° Impedance Length 70 km 120 km 55 km The three relays are connected as shown below. GE Multilin L90 Line Current Differential System 9-51...
  • Page 576 Relay 3: 1.2775 pu 56.917° – When subjected to the expanded Clarke transform in the previous sub-section, the local voltages yield the following values (in per-unit values of the nominal primary phase-to-ground voltage): 9-52 L90 Line Current Differential System GE Multilin...
  • Page 577 Note that the correct value of the tap voltage is equal for all three relays. This is expected since the per-unit base for the composite voltages is equal for all three relays. The three relays calculate the differences as follows (refer to the previous sub-section for equations). GE Multilin L90 Line Current Differential System 9-53...
  • Page 578 The actual fault location in this example was 50.00km from relay 2 as shown below. channel 1 channel 1 Relay 1 Relay 2 50 km 70 km 120 km channel 2 channel 2 Relay 3 channel 1 channel 2 831812A1.CDR Figure 9–17: ACTUAL FAULT LOCATION 9-54 L90 Line Current Differential System GE Multilin...
  • Page 579: Single-ended Fault Locator

    Im() represents the imaginary part of a complex number. Solving the above equation for the unknown m creates the following fault location algorithm:     Im V --------------------------------------- - (EQ 9.60)      Im Z I where * denotes the complex conjugate and Apre GE Multilin L90 Line Current Differential System 9-55...
  • Page 580 -- - V (EQ 9.68) SYS0   Z -- - V SYS0 where Z is the equivalent zero-sequence impedance behind the relay as entered under the fault report setting menu. SYS0 9-56 L90 Line Current Differential System GE Multilin...
  • Page 581 Since the fault locator algorithm is based on the single-end measurement method, in three-terminal config- uration the estimation of fault location may not be correct at all three terminals especially if fault occurs NOTE behind the line's tap respective to the given relay. GE Multilin L90 Line Current Differential System 9-57...
  • Page 582 9.6 FAULT LOCATOR 9 THEORY OF OPERATION 9-58 L90 Line Current Differential System GE Multilin...
  • Page 583: Application Of Settings

    CTs. Ideally, CTs selected for line current differential protection should be based on the criteria described below. If the available CTs do not meet the described criteria, the L90 will still provide good security for CT saturation for external faults.
  • Page 584: Calculation Example 2

      0.008   ---------------------------------- - 4.71 0.75 0.52 291.89 V (< 300 V, which is OK) (EQ 10.9) ratio of 300:1 The CT will provide acceptable performance in this application. 10-2 L90 Line Current Differential System GE Multilin...
  • Page 585: Current Differential (87l) Settings

    10.2CURRENT DIFFERENTIAL (87L) SETTINGS 10.2.1 INTRODUCTION Software is available from the GE Multilin website that is helpful in selecting settings for the specific appli- cation. Checking the performance of selected element settings with respect to known power system fault parameters makes it relatively simple to choose the optimum settings for the application.
  • Page 586: Ct Tap

    For relay 1, channel 1 communicates to relay 2 and channel 2 communicates to relay 3 • For relay 2, channel 1 communicates to relay 1 and channel 2 communicates to relay 3 10-4 L90 Line Current Differential System GE Multilin...
  • Page 587 This satisfies the equality condition indicated earlier. During on-load tests, the differential current at all terminals should be the same and generally equal to the charging current if the tap and CT ratio settings are chosen correctly. GE Multilin L90 Line Current Differential System 10-5...
  • Page 588: Breaker-and-a-half

    Assume a breaker-and-the-half configuration shown in the figure below. This section provides guidance on configuring the L90 relay for this application. The L90 is equipped with two CT/VT modules: F8F and L8F. CTs and VTs are connected to L90 CT/VT modules as follows: –...
  • Page 589 CURRENT DIFF SIGNAL to “SRC 1” and to “SRC 2”. SOURCE 1 CURRENT DIFF SIGNAL SOURCE 2 For distance and backup overcurrent, make the following settings changes (EnerVista UR Setup example shown): GE Multilin L90 Line Current Differential System 10-7...
  • Page 590 10 APPLICATION OF SETTINGS For breaker failure 1 and 2, make the following settings changes (EnerVista UR Setup example shown): For synchrocheck 1 and 2, make the following settings changes (EnerVista UR Setup example shown): 10-8 L90 Line Current Differential System GE Multilin...
  • Page 591: Distributed Bus Protection

    CT cable length. In other cases, there are no CTs available on the line side of the line to be protected. Taking full advantage of L90 capability to support up to 4 directly- connected CTs, the relay can be applied to protect both line and buses as shown below.
  • Page 592: Channel Asymmetry Compensation Using Gps

    If GPS is enabled at all terminals and the GPS signal is present, the L90 compensates for the channel asymmetry. On the loss of the GPS signal, the L90 stores the last measured value of the channel asymmetry per channel and compensates for the asymmetry until the GPS clock is available.
  • Page 593: Compensation Method 2

    Create FlexLogic™ similar to that shown below to switch the 87L element to Settings Group 2 (with most sensitive set- tings) if the L90 has a valid GPS time reference. If a GPS or 87L communications failure occurs, the L90 will switch back to Settings Group 1 with less sensitive settings.
  • Page 594 Set the 87L element with different differential settings for Settings Groups 1 and 2 as shown below Enable GPS compensation when the GPS signal is valid and switch to Settings Group 2 (with more sensitive settings) as shown below. 10-12 L90 Line Current Differential System GE Multilin...
  • Page 595: Distance Backup/supervision

    LV fault. For this system configuration, a 3-ter- minal L90 should be utilized; the third terminal is then fed from CT on the high side of the tapped transformer.
  • Page 596: Phase Distance

    The current supervision alone would not prevent maloperation in such circumstances. It must be kept in mind that the fuse failure element provided on the L90 needs some time to detect fuse fail conditions. This may create a race between the instantaneous zone 1 and the fuse failure element. Therefore, for maximum security, it is recommended to both set the current supervision above the maximum load current and use the fuse failure function.
  • Page 597: Ground Distance

    To avoid extremely large reach settings, the L90 has the ability to implement any element so that it is reverse looking, which then can provide a back up for the longest line terminated on the local bus. This strategy can be beneficial if the reduced reach helps discrimination between the load and fault conditions, but must be implemented at both ends of the protected line.
  • Page 598 To avoid extremely large reach settings the L90 has the ability to implement any element, so that it is reverse looking. This strategy can be beneficial if the reduced reach enhances the discrimination between the load and fault conditions.
  • Page 599: Protection Signaling Schemes

    10 APPLICATION OF SETTINGS 10.5 PROTECTION SIGNALING SCHEMES 10.5PROTECTION SIGNALING SCHEMES 10.5.1 OVERVIEW The L90 includes six common pilot-aided schemes: • direct under-reaching transfer trip (DUTT) • permissive under-reaching transfer trip (PUTT) • permissive over-reaching transfer trip (POTT) • hybrid permissive over-reaching transfer trip (Hybrid POTT) •...
  • Page 600: Hybrid Pott Scheme (hyb-pott)

    This situation is encountered when it is desired to account for the zero sequence inter-circuit mutual cou- pling. This is not a problem for the ground distance elements in the L90 which do have a current reversal logic built into their design as part of the technique used to improve ground fault directionality.
  • Page 601: Directional Comparison Blocking

    Typically, the output operand should be pro- grammed to initiate a trip, breaker fail, and auto-reclose, and drive a user-programmable LED as per user application. GE Multilin L90 Line Current Differential System 10-19...
  • Page 602: Directional Comparison Unblocking

    This loss-of-guard output should be connected to a contact input of the L90. The power line carrier should also provide an output contact when the permissive frequency is received. This output should be wired to any other contact input of the L90.
  • Page 603 The permissive key carrier signals through must still be assigned to the DCUB TX1 DCUB TX4 tripping/operating logic, and to output contacts as per the usual L90 logic/output assignments. GE Multilin L90 Line Current Differential System 10-21...
  • Page 604: Series Compensated Lines

    It is strongly rec- ommended to use a power system simulator to verify the reach settings or to use an adaptive L90 feature for dynamic reach control.
  • Page 605: Ground Directional Overcurrent

    Net inductive reactance from relay through far-end busbar = 10 – 4 = 6 ; the offset cannot be higher than 6 . • It is recommended to use 3.5  offset impedance. • GE Multilin L90 Line Current Differential System 10-23...
  • Page 606: Description

    The L90 protection system could be applied to lines with tapped transformer(s) even if the latter has its windings connected in a grounded wye on the line side and the transformer(s) currents are not measured by the L90 protection system. The fol- lowing approach is recommended.
  • Page 607: Lv-side Faults

    LV busbars of all the tapped transformers. This may present some challenges, particularly for long lines and large transformer tapped close to the substations. If the L90 system retrofits distance relays, there is a good chance that one can set the distance elements to satisfy the imposed. If more than one transformer is tapped, partic- ularly on parallel lines, and the LV sides are interconnected, detailed short circuit studies may be needed to determine the distance settings.
  • Page 608: Instantaneous Elements

    10.8.1 INSTANTANEOUS ELEMENT ERROR DURING L90 SYNCHRONIZATION As explained in the Theory of Operation chapter, two or three L90 relays are synchronized to each other and to system fre- quency to provide digital differential protection and accurate measurements for other protection and control functions.
  • Page 609: Phase Distance Through Power Transformers

    10.9.1 PHASE DISTANCE PROTECTION a) DESCRIPTION Phase distance elements of the L90 could be set to respond to faults beyond any three-phase power transformer. The relay guarantees accurate reach and targeting for any phase fault. Moreover, the current and voltage transformers may be located independently on different sides of the transformer.
  • Page 610: Example

    PHS DIST Z1 XMFR VOL CONNECTION: "Dy1" PHS DIST Z1 XMFR CUR CONNECTION: The settings are: "2.60" PHS DIST REACH: "89" PHS DIST RCA: "Yd11" PHS DIST XMFR VOL CONNECTION: "None" PHS DIST XMFR CUR CONNECTION: 10-28 L90 Line Current Differential System GE Multilin...
  • Page 611: Commissioning

    G.703, and RS422. The speed is 64 Kbaud in a transparent synchronous mode with automatic synchronous character detection and CRC insertion. The Local Loopback Channel Test verifies the L90 communication modules are working properly. The Remote Loopback –4 Channel Test verifies the communication link between the relays meets requirements (BER less than 10 ).
  • Page 612: Clock Synchronization Tests

    “OK” ACTUAL VALUES STATUS CHANNEL TESTS CHANNEL 1(2) STATUS:    “n/a” ACTUAL VALUES STATUS CHANNEL TESTS REMOTE LOOPBACK STATUS:    “OK” ACTUAL VALUES STATUS CHANNEL TESTS PFLL STATUS: 11-2 L90 Line Current Differential System GE Multilin...
  • Page 613: Current Differential

    • Restore the communication circuits to normal. Download the UR Test software from the GE Multilin website (http://www.GEindustrial.com/multilin) or contact GE Multilin for information about the UR current differential test program which allows the user to simulate different operating conditions for verifying correct responses of the relays during commissioning activities.
  • Page 614: Local-remote Relay Tests

    These phasors and differential currents can be monitored at the ACTUAL VAL-   menu where all current magnitudes and angles can be observed and con- METERING 87L DIFFERENTIAL CURRENT clusions of proper relay interconnections can be made. 11-4 L90 Line Current Differential System GE Multilin...
  • Page 615: Parameter Lists

    SRC 1 Igd Angle Amps Source 1 differential ground current angle 6208 SRC 2 Ia RMS Amps Source 2 phase A current RMS 6210 SRC 2 Ib RMS Amps Source 2 phase B current RMS GE Multilin L90 Line Current Differential System...
  • Page 616 SRC 4 Ia RMS Amps