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Siemens 7sg15 microtapp Operation Manual

Automatic voltage control
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  • Page 1 Reyrolle Protection Devices 7SG15 MicroTAPP Automatic Voltage Control Answers for energy...
  • Page 2 Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.

  • Page 3: Description Of Operation

    Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.

  • Page 4: Table Of Contents

    7SG15 MicroTAPP Description of Operation Contents Introduction............................4 Power system requirements......................4 MicroTAPP Functionality........................4 Inputs............................4 3.1.1 Voltage Measurement......................5 3.1.2 Current Measurement......................5 3.1.3 Status..........................5 Outputs ............................5 Description of operation ........................6 General............................6 Transformers in Parallel ......................8 4.2.1...
  • Page 5 7SG15 MicroTAPP Description of Operation 7.1.2 Control Switches......................21 7.1.3 Relay Healthy ........................21 7.1.4 Voltmeter ......................... 21 7.1.5 Voltage Trace ........................21 7.1.6 Tap Position Indicator (TPI)..................... 21 7.1.7 Instruments ........................22 Data Storage with Date and Time .................... 22 7.2.1...

  • Page 6: Introduction

    7SG15 MicroTAPP Description of Operation Introduction The MicroTAPP voltage control and monitor system is an advanced numeric system based on the widely used SuperTAPP relay. The operational requirements for efficient control of tap changing transformers and protection against abnormal voltage levels is provided in a compact and user friendly design contained within a standard Epsilon case of 4U (177mm) in height and E8 (208mm) or E12 (312mm) in width.

  • Page 7: Voltage Measurement

    7SG15 MicroTAPP Description of Operation 3.1.1 Voltage Measurement The VT input to the relay is measured against the target settings applied via the menu system. The voltage is only used for measurement if the voltage quality is confirmed as satisfactory by the voltage monitor.

  • Page 8: Description Of Operation

    7SG15 MicroTAPP Description of Operation Description of operation General Operate Time Initial Delay Initial Delay IDMTL Initial Delay Relay 80% Volts Deadband Figure 2 The MicroTAPP provides a system, at each point where voltage is regulated, that operates at all times with minimal human intervention and is capable of optimal operation under various power network arrangements.
  • Page 9 7SG15 MicroTAPP Description of Operation Figure 3 The initial delay timer increments (A) until the timer display is full, when a tap-change signal is issued (B). At this time the display resets and the inter-tap delay timer increments, shown by C, while the initial timer is held at the operative value.

  • Page 10: Transformers In Parallel

    7SG15 MicroTAPP Description of Operation The following standard system conditions are catered for with minimal or no adjustment to the MicroTAPP: - Where a transformer is in parallel with other transformers, either within a site or across a network, when set to TAPP mode, the relay operates in order to: - •...
  • Page 11 7SG15 MicroTAPP Description of Operation Voltage IT1load IT2load IT2circ I load IT1circ Figure 4 For explanation of the relay action consider a situation where 2 transformers are operating in parallel at a site. Each MicroTAPP relay receives the same voltage by virtue of the common connection, represented in Figure 5 by ‘A’.

  • Page 12: Negative Reactance Circulating Current Control - Tapp

    7SG15 MicroTAPP Description of Operation Time Upper Band T1 measured voltage System voltage T2 measured voltage Lower Band Figure 5 It is not possible for this method of circulating current control to be used when networks are operated in parallel as the summed load at that site can also contain reactive current flowing between remote transformers.

  • Page 13: Master/Follower Control

    7SG15 MicroTAPP Description of Operation Measurement Error -VXT1 Voltage Figure 7 When conventional negative reactance control is used the transformer current, IT1, is used to produce a voltage – VXT1, which should have no effect on the relay for load current. When the load current power factor is less than unity, as shown, an error voltage is introduced into the circuitry which causes the relay to measure an incorrect higher voltage that results in a tendency to reduce the power system voltage below the required level.

  • Page 14: Location Of Tap-Changer, Hv Or Lv Side

    7SG15 MicroTAPP Description of Operation Power Flow Controlled Network MicroTAPP Figure 8 If a network configuration makes it necessary to change the controlled voltage point, a voltage and current transformer would be required on the other side of the power transformer together with a complex switching arrangement for the tap-changer control system.

  • Page 15: Single Phase Or 3 Phase Units

    7SG15 MicroTAPP Description of Operation The tap spacing is calculated regardless of the tap-changer location: - Vhi* = Highest voltage of the variable voltage winding (voltage as nameplate) Vlo* = Lowest voltage of the variable voltage winding (voltage as nameplate)

  • Page 16: Transformer Switch In

    7SG15 MicroTAPP Description of Operation When the load current is removed from the transformer to be switched out, the remaining relays return to normal tap change control. If the load current is not removed, after a period of time the relays reset to normal operation.

  • Page 17: Circulating Current Compensation

    Reactive current minimisation, an enhanced version of the TAPP patented system as used with the SuperTAPP range of Siemens Protection Devices Ltd equipment. Using this system, widely recognised for its operational advantages, transformers can operate in parallel either at a site or across a network thus giving greater network flexibility.

  • Page 18: At The Voltage Control Relay Panel

    7SG15 MicroTAPP Description of Operation 5.1.2 At the voltage control relay panel A Local/Remote selector switch on the MicroTAPP, when set to Local, disables control from a remote control centre. If the tap change is set to Local at the tap change mechanism, Auto/Manual selection can still be altered and will take effect when the MicroTAPP is enabled.

  • Page 19: Protection

    7SG15 MicroTAPP Description of Operation Protection A comprehensive monitoring of the voltage control system is incorporated that will detect and prevent abnormal power system voltages either from incorrect operation of a tap changing mechanism or from incorrect control signals. Voltage and Current 6.1.1 Measured voltage outside normal range...

  • Page 20: Voltage Transformer Faulty

    7SG15 MicroTAPP Description of Operation Figure 12 Assume that the voltage is approaching the high voltage setting level. If a tap change is issued it will be an instruction to lower the voltage, therefore for safety, the raise output logic can be blocked. The same argument can be applied to the low voltage setting level.

  • Page 21: Load Current

    7SG15 MicroTAPP Description of Operation 6.1.3 Load Current If the true load current is greater than a pre-set limit, the relay system will inhibit tap control outputs to the and generate an over-current alarm, unless the situation is caused by circulating current flowing between transformers, in which case tap changing will be enabled that will reduce the circulating current, see Figure 12.

  • Page 22: Tap Change Incomplete

    7SG15 MicroTAPP Description of Operation For an incorrect tap change, Figure 14, where the mechanism over-runs, or continues to operate, a new control signal AND/OR ‘in progress’ is detected before the internally generated reclaim time has expired. The tap change has not satisfied rule 3 above, and a further tap position change will result in a lockout signal and the TIP LED will flash.

  • Page 23: Other Features

    7SG15 MicroTAPP Description of Operation Other Features Instrumentation and Metering The MicroTAPP gives indications, shown by reference to the general layout in appendix A as follows: - 7.1.1 System ID The relay has provision for input of a control system ID, e.g. "Transformer 1".

  • Page 24: Instruments

    7SG15 MicroTAPP Description of Operation The tap customisation sub-menu is used to change the tap positions as follows:- -5 -4 -3 -2 -1 0 10 11 7.1.7 Instruments Extensive instrumentation is available from the LCD display or a remotely connected PC. Figure 15 shows the general format of the instrument display, the complete range of instrumentation is listed in section 9, Settings and Displays.

  • Page 25: Event Records

    Two fibre optic communication ports are provided. Communication is compatible with the IEC60870-5-x FT 1.2 transmission and application standards. A user friendly software package available on the Siemens Protection Devices Ltd website, Reydisp Evolution, is freely available to allow transfer of the following: •...

  • Page 26: User Interface

    The MicroTAPP relay fascia includes a 40 character by 8 line, back-lit, liquid crystal display, 5 light emitting diodes and 5 push buttons. Appendix A shows the layout for the E8 case size. Detailed drawings for both the E8 and E12 wiring connector blocks are available from the Siemens Protection Devices Ltd website.
  • Page 27 7SG15 MicroTAPP Description of Operation Note that applying Auxiliary Target Voltages, Circulating Current compensation or Frequency compensation will not adjust the graphical display target voltage. In some cases, therefore, the voltage trace will be outside the band without Raise or Lower operations being initiated.

  • Page 28: Serial Communications Port

    7SG15 MicroTAPP Description of Operation Locked Out The Relay has Locked Out. V out of band The voltage is outside the Dead Band but the Relay is under Manual control and so cannot correct it automatically. V very low The voltage is below 80% of the nominal Primary Voltage.

  • Page 29: Settings And Displays

    7SG15 MicroTAPP Description of Operation Settings and Displays The basic settings/displays flow diagram is shown in Figure 19. This diagram shows the main modes of display, the Settings Mode, Instrument Display Mode and the Fault Data Display Mode. Intuitive operation of the push buttons allows each mode to be entered where further menu options enable settings to be entered.
  • Page 30 7SG15 MicroTAPP Description of Operation NOTE: [101] MicroTAPP 101 only [102] MicroTAPP 102 only System Configuration Active Group 8 Settings Groups are provided. Selects the Group in use. View/Edit Group The Settings Group displayed on the LCD. Status Select Group Mode Configures the "Select Group"...
  • Page 31 7SG15 MicroTAPP Description of Operation Tap Changer Runaway Enables Tap Changer Runaway Detection and Lockout. Detection Tap Pulse Length Duration of Tap Change - Raise or Lower - signals. Tap Changer Scheme Step by Step control prevents repetitive operations in the event of a persistent Raise or Lower signal being applied to the Tap Changer.
  • Page 32 7SG15 MicroTAPP Description of Operation Auxiliary Target 2 Temporary change to target voltage. This adjustment applies as long as the “Select Auxiliary Target 2” input is active. Auxiliary Target 3 Temporary change to target voltage. This adjustment applies as long as the “Select Auxiliary Target 3” input is active.
  • Page 33 7SG15 MicroTAPP Description of Operation Block Raise Command The relay is blocking Raise operations. Can be used to block Raise commands initiated externally to Relay. Block Lower Command The relay is blocking Lower operations. Can be used to block Lower commands initiated externally to Relay.
  • Page 34 7SG15 MicroTAPP Description of Operation Remote Raise Initiate manual Tap Raise operation - Relay must be in Manual and Remote modes. Remote Lower Initiate manual Tap Lower operation - Relay must be in Manual and Remote modes. Remote Auto Switch to Auto operation – Relay must be in Remote mode.

  • Page 35: Instruments

    7SG15 MicroTAPP Description of Operation Clear Delta Tap-change count Resets the maintenance count. Clear Delta Sum of I count Resets the maintenance total. Instruments A comprehensive set of readings are available from the relay. These are accessed as shown in Figure 19 and...

  • Page 36: Relay Hardware

    7SG15 MicroTAPP Description of Operation Relay Hardware MicroTAPP relays are housed in either the Epsilon E8 or E12 case, depending on input/output configurations. The fascia PCB forms the human machine interface (HMI), with pushbuttons for entering settings, an LCD for displaying alphanumeric messages and LEDs for indication.

  • Page 37: Appendix A

    7SG15 MicroTAPP Description of Operation Appendix A ©2013 Siemens Protection Devices Limited Chapter 1 Page 35 of 38...

  • Page 38: Appendix B

    7SG15 MicroTAPP Description of Operation Appendix B MicroTAPP Rear View (E8 case) MicroTAPP Rear View (E12 case) Note that the identification letter at the top of the card, A, B, C, D, E, refers to its position within a particular case.

  • Page 39: Appendix C

    7SG15 MicroTAPP Description of Operation Appendix C CANH CANL External Link for Line CAN GND Termination - only fitted on Relay at end of Can-bus Terminating Resistor is internal to Relay Digital wiper Analogue see note 3 see note 2...

  • Page 40: Appendix D

    7SG15 MicroTAPP Description of Operation Appendix D Overall Dimensions and panel drilling for Epsilon E8 case Overall Dimensions and panel drilling for Epsilon E12 case ©2013 Siemens Protection Devices Limited Chapter 1 Page 38 of 38...

  • Page 41: The Copyright And Other Intellectual Property Rights In This Document, And In Any Model Or Article Produced From It (And

    Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.
  • Page 42 7SG15 MicroTAPP Performance Specification Contents General................................3 Characteristics..............................3 Auxiliary energising quantities ........................4 Status Inputs ..............................5 Output Contacts ............................. 5 Thermal withstand ............................6 Accuracy................................. 6 Environmental withstand ..........................7 ©2010 Siemens Protection Devices Limited Chapter 2 Page 2 of 8...

  • Page 43: General

    7SG15 MicroTAPP Performance Specification 1. General These are preliminary performance specification. 2. Characteristics 2.1 Energising Quantities Single-phase current (any phase) and 3-phase voltages will be measured at 50 or 60Hz. Measured Quantity Nominal Values Measured Range AC Voltage 110V RMS...

  • Page 44: Auxiliary Energising Quantities

    7SG15 MicroTAPP Performance Specification No. of transformers 1 to 16 step 1 Initial Assumed System Power Factor 0.85 to 1.0 step 0.01 leading and lagging 2.5 Coupling The coupling level is entered as the nameplate impedance of the transformer. If the coupling is set other than zero then the transformers’...

  • Page 45: Status Inputs

    7SG15 MicroTAPP Performance Specification 4. Status Inputs Nominal Operating Range 30/34 V AC or DC 18 to 37.5 V 48/54 V AC or DC 37.5 to 60 V 110/125 V AC or DC 87.5 to 137.5 V 220/250 V AC or DC 175 to 280 V 4.1 Electricity Association ESI48-4...

  • Page 46: Thermal Withstand

    7SG15 MicroTAPP Performance Specification 6. Thermal withstand 6.1 CT Inputs 3.0 x I continuous 3.5 x I 10 min 100A 1 sec 2500A 1 cycle 6.2 VT Inputs 250Vrms continuous 7. Accuracy 7.1 Accuracy Reference Conditions Settings All settings Auxiliary Supply...

  • Page 47: Environmental Withstand

    7SG15 MicroTAPP Performance Specification Operating time variation ≤ 5% 7.3.3 Harmonic Content Harmonic Content Frequencies to 350Hz Setting Variation ≤ 5% Operating time variation ≤ 5% 7.3.4 Auxiliary Supply (DC) Allowable superimposed A.C. component ≤ 12% of D.C. level Allowable breaks/dips in supply (collapse to zero ≤...
  • Page 48 7SG15 MicroTAPP Performance Specification Radio Frequency Interference - IEC 60255-2-3 Class III 20MHz to 1000MHz, 10V/m variation ≤ 5% 8.8 Fast Transient - IEC 60255-22-4 Class IV 4kV 5/50ns, 2.5kHz repetitive variation ≤ 3% 8.9 Vibration (Sinusoidal) - IEC 60255-21-1 Class I Vibration response, 0.5gn...

  • Page 49: The Copyright And Other Intellectual Property Rights In This Document, And In Any Model Or Article Produced From It (And

    Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.
  • Page 50 [102] Advanced Control Menu ...................... 5 Voltage Control Menu........................5 Output Config Menu ........................6 Status Config Menu........................7 Communications Menu......................... 8 Data Storage Menu ........................8 TAP-Changer Maint. Menu......................8 ©2012 Siemens Protection Devices Limited Chapter 3 Page 2 of 8...

  • Page 51: System Config Menu

    C 0 to 1000 @ step of 1, 1500 ms (milliseconds) 1010 to 10,000 @ step of 10, 10,100 to 60,000 @ step of 100 Tap-changer Scheme C Basic or Step-by-Step Basic ©2012 Siemens Protection Devices Limited Chapter 3 Page 3 of 8...

  • Page 52: Network Config Menu

    85 to 115 @ step of 0.1 94 % (% of nominal voltage) Auxiliary Target 3 85 to 115 @ step of 0.1 103 % (% of nominal voltage) ©2012 Siemens Protection Devices Limited Chapter 3 Page 4 of 8...

  • Page 53: 102] Advanced Control Menu

    75 to 125 @ steps of 1 95 % (% of nominal voltage) Overload Blocking Level 80 to 200 @ steps of 5 100 % (% of Transformer Capacity) ©2012 Siemens Protection Devices Limited Chapter 3 Page 5 of 8...

  • Page 54: Output Config Menu

    C RL 1 to RL 5 (to RL 13) NONE NOTE: the available settings in this Menu will be dependant upon the number of hardware output relays fitted. * These operations also result in a Lockout. ©2012 Siemens Protection Devices Limited Chapter 3 Page 6 of 8...

  • Page 55: Status Config Menu

    NOTE: the available settings in this Menu will be dependant upon the number of hardware status inputs fitted. * These inputs are positive edge triggered. All other inputs are level dependant. ** These operations may be configured as edge or level triggered. ©2012 Siemens Protection Devices Limited Chapter 3 Page 7 of 8...

  • Page 56: Communications Menu

    10 to 1000 @ step of 10, 2000 to 99,000 @ step of 1000 Clear Delta Tap Change Count NO or YES Clear Delta Sum of I^2 Count NO or YES ©2012 Siemens Protection Devices Limited Chapter 3 Page 8 of 8...

  • Page 57: The Copyright And Other Intellectual Property Rights In This Document, And In Any Model Or Article Produced From It (And

    Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.
  • Page 58 7SG15 MicroTAPP Communications Interface Contents Introduction..........................3 Connections..........................3 Physical Characteristics ......................3 Fibre Optic Cable ........................4 Connection Methods ........................4 Relay Settings ..........................4 Transmission Method ......................... 4 Communications Menu....................... 4 Fibre Optic Data ......................... 5 Launch Power (dBm)........................5 Receiver Sensitivity (dBm) ......................

  • Page 59: Introduction

    7SG15 MicroTAPP Communications Interface 1 Introduction The MicroTAPP relay has provision for communication either locally to a computer or remotely to an operations centre. The Communication Interface, Figure 1, incorporates the following ports: • A pair of fibre optic ST connectors for transmit and receive communications to a substation SCADA or integrated control system (Com 1).

  • Page 60: Fibre Optic Cable

    7SG15 MicroTAPP Communications Interface 2.2 Fibre Optic Cable The modular II relay is optimised to use either a 50/125 µm or 62.5/125 µm glass fibre optic cable. Fibre-optic transmission distances vary with transmitter, receiver and type of fibre. The tables at the end of this section show the achievable distances between Reyrolle devices.

  • Page 61: Fibre Optic Data

    7SG15 MicroTAPP Communications Interface The sigma units 1 & 3 contain switches to switch between Light off and Light on. On Sigma 4 this is achieved with a jumper connection, jumper OFF is light off. This setting has no effect on the electrical Com2 port.

  • Page 62: Distances

    7SG15 MicroTAPP Communications Interface 4.4 Distances These figures are based on manufacturers’ data and may be subject to change without notice. No account is taken of minimum distances. With certain fibres, it is possible to overload the receivers thus causing errors. All distances are in metres, and are maximum figures, allowing for LED degradation.
  • Page 63 7SG15 MicroTAPP Communications Interface 50/125 µm glass DESTINATION SOURCE Argus Argus Modular I Modular II Sigma 1 Sigma 3 Sigma 3 Sigma 4 Sigma (ST) Argus (p) Argus Modular I Modular II Sigma 1 Sigma 3 (p) Sigma 3 (ST)
  • Page 64 7SG15 MicroTAPP Communications Interface Control System Sigma 3 (SG3-101) Serial optical link Laptop computer Figure 2 - Fibre Optic Ring Connection using Sigma 3 Note, each Serial Optical Link consists of two fibres, a transmit and a receive Control System...

  • Page 65: The Copyright And Other Intellectual Property Rights In This Document, And In Any Model Or Article Produced From It (And

    Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.
  • Page 66 7SG15 MicroTAPP Application Guide Contents Introduction ............................. 3 Voltage Standards .......................... 3 Wiring Diagrams ..........................4 Application of TAP change control ....................4 MT1-102 Advanced Relay - Application Guide ................9 Network Control ..........................10 Voltage Transformers ........................12 Current Transformers ........................13 Wiring Configurations ........................

  • Page 67: Introduction

    7SG15 MicroTAPP Application Guide 1 Introduction The comprehensive design of the MicroTAPP relay simplifies the design of a tap change control system allowing a large reduction in the external wiring normally required. Application of the relay for voltage control of the most complex networks is easily accomplished.

  • Page 68: Wiring Diagrams

    7SG15 MicroTAPP Application Guide If use of LDC is considered as LOAD Drop Compensation it can be employed in a practical way to increase the network utilisation. Using the data from Table 1 as an example, a modified basic level setting of -4% and an LDC setting of 8% is applied to the AVC.
  • Page 69 7SG15 MicroTAPP Application Guide 4.1 TAPP Method – System Power Factor Setting The TAPP method uses the “System Power Factor” setting applied to the relay with which to calculate the circulating current compensation. This setting is also used to normalise the line drop compensation applied, so that it is not affected by any circulating current and only relates to the load power factor.
  • Page 70 7SG15 MicroTAPP Application Guide MicroTAPP Figure 1 4.3 Parallel Transformers When transformers are operated in parallel at a site use of the MPPC link between each voltage control relay enables accurate LDC at all times. Figure 2 shows the general MPPC arrangement for a multiple transformer site.
  • Page 71 7SG15 MicroTAPP Application Guide The actual level of LDC for each of the two bus-bar groups will be proportional to the load on each of the respective bus-bars and these levels will be maintained (by virtue of the MPPC) at the correct level even if one transformer is taken out of service in either of the groups.
  • Page 72 7SG15 MicroTAPP Application Guide 4.5.1 Generator Types 4.5.1.1 Synchronous Synchronous generator control systems can control the generator terminal voltage and the power factor of load. The generator control can be set to run in power factor or voltage control mode. In either case the excitation is adjusted to hold either of these parameters within limits.

  • Page 73: Mt1-102 Advanced Relay - Application Guide

    7SG15 MicroTAPP Application Guide 5 MT1-102 Advanced Relay - Application Guide The advanced MicroTAPP relay (MT1-102) is available for applications where MW and MVar power flow is more dynamic, for instance when applied to Generator step up Transformers or at embedded generation sites. It has features that allow widely fluctuating loads to be accommodated on industrial supplies.

  • Page 74: Network Control

    7SG15 MicroTAPP Application Guide In a situation where a load fluctuates wildly, such a when running large motors or furnaces intermittently, automatic voltage control can result in an excessive number of tap change operations caused by the impedance drop through the transformer. In this instance the menu selection ‘transformer voltage drop compensation’ can be disabled.
  • Page 75 7SG15 MicroTAPP Application Guide relay. The preparation sequence is shown in Figure 8. On receipt of a switch-out signal (A), the nominated MicroTAPP will immediately tap down until its measured power factor is unity and send a warning signal to other relays in the same group.

  • Page 76: Voltage Transformers

    7SG15 MicroTAPP Application Guide Status Input CB aux. switch MicroTAPP MicroTAPP C1+2 Summed Load Figure 9 When the compensator is switched in, reactive current will flow through the LDC CT in the ‘wrong direction’ causing the apparent power factor to change. If reactive circulating current control is used for control of parallel transformers, the change in power factor will tend to make T2 operate at a higher voltage.

  • Page 77: Current Transformers

    7SG15 MicroTAPP Application Guide Errors in the controlled voltage will be directly related to errors in the measured voltage and so these should be minimised by using the most accurate VTs available. As a guide the measuring accuracy of the VTs should be matched to the tap step resolution as a minimum requirement.

  • Page 78: Wiring Configurations

    7SG15 MicroTAPP Application Guide 9 Wiring Configurations Diagrams located at the end of this section show typical arrangements for tap change control schemes. Inputs to the relay and outputs for indications and control are user programmable. Tables 5, 6 and 7 give examples of the I/O allocation for a complete control system as shown in the example scheme with the inclusion of other features not shown on the diagrams.
  • Page 79 7SG15 MicroTAPP Application Guide 9.1 Voltage Transformers Either a 3 phase or single phase voltage transformers can be used for voltage measurement. A 3 phase VT is preferable so that the level and voltage quality of all phases can be monitored. Figure 10 shows the relay connections for a 3 phase VT.
  • Page 80 7SG15 MicroTAPP Application Guide 9.3 Inputs The standard status inputs to the relay are rated for AC or DC voltages and have a range of 18V to 110V. When used at higher voltages up to 250V AC or DC, a series dropper resistor must be used as shown in the application diagrams at the end of this section.
  • Page 81 7SG15 MicroTAPP Application Guide MicroTAPP position Switch +12V supplied by MicroTAPP Figure 13 9.6 Transfer Tap Positions As described in the first section of this manual some tap changers have special positions which operate to re- arrange the winding configuration but do not alter the voltage. When at these positions a single tap change control will result in more than one tap change operation which must be recognised for correct operation of the runaway prevention system.
  • Page 82 7SG15 MicroTAPP Application Guide If an MPPC failure is detected when the relay is in circulating current mode (the "MPPC Failure Detection" setting in the "System Config" Menu must be set to "Enabled" for this to occur), the relay will automatically switch to TAPP mode.
  • Page 83 7SG15 MicroTAPP Application Guide ©2011 Siemens Protection Devices Limited Chapter 5 Page 19 of 21...
  • Page 84 7SG15 MicroTAPP Application Guide ©2011 Siemens Protection Devices Limited Chapter 5 Page 20 of 21...
  • Page 85 7SG15 MicroTAPP Application Guide ©2011 Siemens Protection Devices Limited Chapter 5 Page 21 of 21...

  • Page 86: The Copyright And Other Intellectual Property Rights In This Document, And In Any Model Or Article Produced From It (And

    Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.
  • Page 87 External Connections ........................4 Earthing............................4 Relay Dimensions ........................4 Fixings............................5 Crimps ............................. 5 Panel Fixing Screws ........................ 5 Communications ........................5 Ancillary Equipment ........................5 Precautions ..........................5 ©2012 Siemens Protection Devices Limited Chapter 6 Page 2 of 5...
  • Page 88 If the LCD appears to be blank, but the Protection Healthy LED is correctly illuminated, the LCD contrast requires adjustment. To do this: • Hold down the RIGHT-most key. • Then hold either the LEFT-most key (contrast raise) or the SECOND LEFT-most key (contrast lower). CHANGE CONTRAST ©2012 Siemens Protection Devices Limited Chapter 6 Page 3 of 5...
  • Page 89 'daisy chain' together the case (safety) earths of all the Relays installed in a panel to prevent earth current loops posing a risk to personnel. 7 Relay Dimensions The relay is supplied in an Epsilon case. Diagrams are provided elsewhere in this manual. ©2012 Siemens Protection Devices Limited Chapter 6 Page 4 of 5...
  • Page 90 If the fibre optic cables are anchored using cable ties, these ties must be hand tightened – under no circumstances should cable tie tension tools or cable tie pliers be used. ©2012 Siemens Protection Devices Limited Chapter 6 Page 5 of 5...

  • Page 91: The Copyright And Other Intellectual Property Rights In This Document, And In Any Model Or Article Produced From It (And

    Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.
  • Page 92 Signal Inputs ..........................4 Automatic Voltage Control ....................... 4 Protection..........................5 Operational Service........................6 Off-Load Testing ........................6 On-Load Tests ......................... 8 Operational Settings ......................10 System Power Factor Settings ....................10 ©2012 Siemens Protection Devices Limited Chapter 7 Page 2 of 10...

  • Page 93: Introduction

    This document details the key testing that should be carried out. Other confirmation tests should be undertaken prior to service, depending on any additional functions incorporated into the design. ©2012 Siemens Protection Devices Limited Chapter 7 Page 3 of 10...

  • Page 94: Insulation

    Prior to despatch full accuracy, function and endurance testing is carried out to confirm correct operation of the relay, further on-site accuracy testing is unnecessary. Final checks for operation can be carried out when the transformer is energised. ©2012 Siemens Protection Devices Limited Chapter 7 Page 4 of 10...

  • Page 95: Protection

    Customised Tap Physical tap 11 and 12 must be changed to tap 10 and the positions above altered to indicate the actual position as shown below. Physical Tap Customised Tap ©2012 Siemens Protection Devices Limited Chapter 7 Page 5 of 10...

  • Page 96: Operational Service

    Decrease the basic setting for a lower voltage so that the relay indicates ‘high’. Confirm that the ‘lower’ contactor is operated Return the setting to balance ©2012 Siemens Protection Devices Limited Chapter 7 Page 6 of 10...
  • Page 97 C26 on the relay. In this case the voltage monitor will block any raise control signals. Set basic control to force MicroTAPP relay to raise voltage. Confirm ‘raise’ control signals are blocked. ©2012 Siemens Protection Devices Limited Chapter 7 Page 7 of 10...

  • Page 98: On-Load Tests

    Confirm that basic balance point agrees with the power system voltage level. Note: If the voltage set point does not appear to be correct the VT/CT phase angle selection may be incorrect. ©2012 Siemens Protection Devices Limited Chapter 7 Page 8 of 10...
  • Page 99 Carry out procedure for a 2 transformer substation on T1 and T2 Carry out procedure for a 2 transformer substation on T2 and T3 Carry out procedure for a 2 transformer substation on T3 and T4 ©2012 Siemens Protection Devices Limited Chapter 7 Page 9 of 10...

  • Page 100: Operational Settings

    System Power Factor Setting applied to all of the relays. An example of this is covered in 4.1 of the Applications Guide. ©2012 Siemens Protection Devices Limited Chapter 7 Page 10 of 10...

  • Page 101: The Copyright And Other Intellectual Property Rights In This Document, And In Any Model Or Article Produced From It (And

    Limited. No part of this document shall be reproduced or modified or stored in another form, in any data retrieval system, without the permission of Siemens Protection Devices Limited, nor shall any model or article be reproduced from this document unless Siemens Protection Devices Limited consent.
  • Page 102 7SG15 MicroTAPP Maintenance Contents Introduction ..........................3 Tests ............................3 Basic Level Set-Point ........................3 Load Drop Compensation (LDC) Set-Point .................. 3 Alarms............................3 Completion ........................... 3 ©2013 Siemens Protection Devices Limited Chapter 8 Page 2 of 3...
  • Page 103 With the tap changer disabled alter the basic setting to allow the relay to read low. Check operation of alarm contacts. 6 Completion On completion of tests all settings can be returned to normal. ©2013 Siemens Protection Devices Limited Chapter 8 Page 3 of 3...
  • Page 104 Printed in Fürth Printed on elementary chlorine-free bleached paper. All rights reserved. Trademarks mentioned in this document are the property of Siemens AG, its affili- ates, or their respective owners. Subject to change without prior notice. The information in this document contains general descriptions of the technical options available, which may not apply in all cases.

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