Treetech PI Technical Manual

Tap position indicator and controller for transformers with on-load tap changer

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TAP POSITION INDICATOR AND

CONTROLLER

Index

Section

Title

Security and Warranty

Operation Philosophy

Operation

III

Project and Installation

Start-up

Troubleshooting

Appendixes

Note: There is a detailed index of each section in the beginning of them.

Technical Manual PI – V1.2

FOR TRANSFORMERS WITH ON-LOAD TAP CHANGER

Technical Manual

MA-005 Rev. 1

16/01/2004

Page i

Page

I – 1

II – 1

III – 1

IV – 1

V – 1

VI – 1

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Page 1 III – 1 Start-up IV – 1 Troubleshooting V – 1 Appendixes VI – 1 Note: There is a detailed index of each section in the beginning of them. Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page i...
Page 2 (Section IV), including the equipment parameterization. TERM OF WARRANTY The Tap Position Indicator and Controller PI shall be warranted by Treetech during 2 (two) years, counting from the acquisition date, exclusively for instances of eventual manufacture defects or quality flaws that can turn the equipment incapable to regular usage.
Page 3 Manual/Automatic Command Modes I - 3 Local/Remote Command Modes I - 3 Index of Pictures Picture Title Page Tap Position Indication and Controller PI I - 2 Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page I - 1...
Page 4 1. Introduction The Tap Position Indicator and Controller PI is a device developed by Treetech to control and to supervise the operation of on-load tap changers (OLTC) in power transformers. Based on microcontrollers, the PI incorporates the functions of several equipment...
Page 5 Automatic/Manual and the commands raise/lower tap, there are three possibilities: a) Local Command, by the PI front keypad; b) Remote Command, by external dry contacts connected to the PI; c) Remote Command, by the serial communication RS485, from a supervisor system.
Page 6 Section II – Operation Index of Subjects Chapter Title Page Local Operation of the PI II – 2 Primary indications in the display II – 2 Local/Remote and Manual/Automatic Selections II – 3 Raise/Lower Tap manual command II – 4 Error Conditions Alarms II –...
Page 7 3. Local Operation of PI The local operation of the PI is done by its front panel, using the P, ↑ and ↓ keys, with the support of the equipment display. 3.1 Primary indications in the display During the system autonomous operation, without the operator intervention by the front keys, the PI display can accomplish one of the following indications: a) Current position of the on-load tap changer associated to it.
Page 8 3.2. 3.2 Local/Remote and Manual/Automatic Selections The Local/Remote and Manual/Automatic selections can be operated in local manner, by the SPS front keyboard, as described below. Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page II - 3...
Page 9 T E C H COMAND. INDIVIDUAL AUTO/REM. MANUAL Procedure Effect Preview If during the previous step the Remote mode was selected, the PI exists the MESTRE + 1 3 T E C H COMAND. INDIVIDUAL programming menu, returning to the AUTO/REM. MANUAL condition described in 3.1...
Page 10 The manual command to Raise and Low the position of the on-load tap changer can be operated in local manner, using the ↑ and ↓ keys of the PI front, as described below. These commands will only be followed if a previous selection of the Local and Manual command modes is done.
Page 11 (C2 cause); • Excessive Electromagnetic interference due to the grounding of the measurement cables shield of the potentiometric position transmitter in more Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page II - 6...
Page 12 Local • The transformer that contains error can only be operated from the on-load Contingency tap changer, as it is not possible to know by the PI what is the real tap position Procedure of the tap changer.
Page 13 III – 14 Mechanical Installation III – 15 Index of Pictures Picture Title Page Topology of PI application III – 3 PI front panel III – 4 Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page III - 1...
Page 14 Contacts connection of Raise/Lower external commands of III – 13 Automatic and Manual operation devices PI signaling contacts III – 13 PI connection diagram III – 14 PI outline dimensions III – 15 Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page III - 2...
Page 15 4. Topology for PI application For each On-Load Tap Changer it is used a unity of the Position Indicator and Controller PI. The serial communication RS485 ports of the PI allow the serial communication of them with an external data acquisition system (supervisor system).
Page 16 In the picture 4.2 it is shown the PI front panel, composed by: 1) Indicator LED for the command mode Manual selected (in Automatic mode this LED turns off); 2) Indicator LED for the command mode Remote selected (in Local mode this LED turns off);...
Page 17 6. 5.1 Auxiliary power and Ground The PI is capable to operate with auxiliary power in the range from 85 to 265V, in AC or DC, 50 or 60Hz, with consumption lower than 6W. It must be effected the connection of the terminal corresponding to the ground ♦...
Page 18 Figure 5.1 – Shield connection of tap measurement cable The PI performs the automatic compensation of the connection cables resistance from the pontentiometric transmitter to the PI, and to such performance, the three wires must have the same length and size, and the maximum acceptable resistance for each wire is 8Ω.
Page 19 (example for 10Ω Ω Ω Ω /step) 12420 3220,6 12696 3150,6 12972 3083,6 13248 3019,3 13524 2957,7 13800 2898,6 14076 2841,7 14352 2787,1 14628 2734,5 14904 2683,8 15180 2635,0 Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page III - 7...
Page 20 5.3 Analog output of tap changer position The PI has an analog output in current loop for remote indication of the tap changer position. The current output value range can be selected using the programming performed in the front of the PI as shown in one of the following options.
Page 21 ♦ Analog output: terminals 10(-) and 11(+). 5.4 Raise/Lower Tap output contacts The output contacts for the Raise Tap and Lower Tap commands of the PI are directly connected to the command circuit of the corresponding on-load tap changer, and generally will act energizing the Raise/Lower contactors, which energize the driving motor.
Page 22 Raise/Lower Tap output contacts. These contacts have momentary acting, in such manner that for each tap changing command emitted by the PI, they will close a single time for about 0,5 second. For this reason, on-load tap changers with intermediary positions, namely, transition positions that have the same voltage of others adjacent positions, as exemplified in the sub-chapter 5.2.2, must have automatic skipping of the intermediary positions.
Page 23 Observe that the Automatic/Manual auxiliary contact of the SPS shown in the picture 5.3.b is used simultaneously in the circuit of the Raise/Lower Tap external command contacts, as described in the sub-chapter 5.5.3. Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004...
Page 24 Raise/Lower Tap contacts inputs are not obeyed, that it is the Manual and Local combination. For this reason, to avoid that the Automatic and Remote Manual commands be received and followed simultaneously by the PI, it is used the Manual/Automatic auxiliary contact of the PI for the interlocking, as shown in the picture 5.4.
Page 25 It must be carefully observed the correspondence between the raise/lower tap and raise/lower voltage commands. In some applications, raise tap can mean lower voltage and vice versa. The Raise/Lower inputs of the PI always refer to the tap position. Figure 5.4 – Connection of external command contacts Raise/Lower for Automatic and Manual operation devices.
Page 26 5.7 Serial Communication RS485 Each PI has a serial communication port RS485. By this communication channel can be accessed all the information, selections and commands of PI. It must be used a 120Ω termination resistor in each extreme of the communication network.
Page 27 In any of these cases, there must be an anti-condensation system. The PI is appropriate for installation of the built-in type; it can be fixed, for an example, in control cubicle door or front plate. The fixing straps are provided with the PI.
Page 28 IV – 7 Parameter OCS IV – 8 Index of Pictures Picture Title Page Individual resistors (step resistance) of the on-load tap IV – 7 changer potentiometric transmitter Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page IV - 1...
Page 29 • If there is no error indications (see sub-chapter 3.6), enable the tap changers remote command, allowing the command by the PI; • Command manually the OLTC by the corresponding PI, passing by all the tap positions. Observe if there is no inversion between the raise and lower tap commands, and also observe if the tap indication is correct in all the positions and if there is no occurrence of tap reading errors (E08);...
Page 30 9. Parametering To ensure the correct operation of the PI, several parameters must be settle in the it, which will provide the equipment the necessary information for its operation. Its front keyboard can perform the adjustments, with the display assistance, or by the serial communication port available to the user.
Page 31 MANUAL general, the current tap position) 9.1 Parameter ADR It is the PI address in the serial communication with a supervisory system. As general rule, each device connected to the same communication network must have a single address, without repetition.
Page 32 Adjustment range: 2 to 50. 9.3 Parameter IDC It is the tap indication type adopted for presentation in the PI display, that generally follows the same indication type used in the proper on-load tap changer. There are four indication options, shown in the following table.
Page 33 It is the resistance by step of the on-load tap changer potentiometric transmitter (in other words, each individual resistor value, shown in the picture 9.1). Adjustment range: 4.7 to 20Ω. Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page IV - 6...
Page 34 • During the CMT time counting, after the emission of a tap change command, the PI indicates in its display that the tap change is in progress by presenting the symbols ∧∧∧ or ∨∨∨ (raising or lowering tap changer, respectively).
Page 35 Adjustment: 1 to 100 seconds. 9.7 Parameter OCS It is the selection of the value range of current in loop analog output of the PI, for remote indication of the on-load tap changer position. The sub-chapter 5.3 presents details of the operation mode of the current output.
Page 36 V – 2 10.2 Raise/Lower tap commands V – 2 10.3 Local and remote indication of tap position V – 3 10.7 Error indication E08 V – 4 Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page V - 1...
Page 37 10. Troubleshooting If difficulties or troubles appear in the operation the PI, we suggest you to consult the possible causes and simple solutions presented below. If this information is not sufficient to solve the difficulties, please get in contact with Treetech's technical assistance or its authorized agent.
Page 38 10.3 Local and Remote Tap position indications • The indication of the tap position in the front panel of the PI does not correspond to the real position of the tap changer Probable Causes...
Page 39 10.4 Error Indication E08 – Tap position reading error To easy the tap reading error diagnostic, it is convenient to consult in the PI the cause of the reading error and the tap position that it was at the moment of the error occurrence.
Page 40 Fix the poor contact in the cables or in position transmitter cursor or in the the potentiometric transmitter cursor connection cables from it to the PI Error in the adjustment of the TAP Correct the adjustment of the TAP and/or RES parameters of the PI...
Page 41 Transmitter of Potentiometric Position of Magnetic type VI – 5 Registers Map VI – 6 General Information VI – 6 Read and Write Registers VI – 6 Read Only Registers VI – 7 Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page VI - 1...
Page 42 Maximum Switching Voltage: 250 Vdc/Vac Maximum Current of Conduction: 2.0 A Serial communication portal: 1 (one) RS485 for connection to supervisory system Communication Protocol: Modbus RTU (slave) Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page VI - 2...
Page 43 Prompt Electric Transients (IEC 61000-4-4) Severity Level: Test in the Power input: Test in the inputs/outputs: Climatic Assay(IEC 60068-2-14) Temperature Range: -10 a +70ºC Test timing: 6 hours Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page VI - 3...
Page 44 Current output for tap remote 0-1, 0-5, 0-10, 0-20 or 4-20mA, with bipolar output option (-/+); Thus, during the PI purchase it is not necessary to inform none of the data above described, because the user parameterizes the device according to its use.
Page 45 Appendix E – Registers Map The information described in this appendix permit that all the measurements, selections, commands and adjustments of the PI be performed by the serial communication port RS485. The utilization of this serial communication is optional. E.1 General Information...
Page 46 Internal use Internal use Internal use 0=idle Select Automatic mode 1=go to Auto/Bank 0=idle Select Manual mode 1=go to Manual/Ind. Phase Invert Local/Remote selection 0=idle 1=invert Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page VI - 6...
Page 47 Internal use Internal use Internal use Internal use Internal use Internal use 0=inactive Tap measuring error E08 1= error E08 Internal use Internal use Internal use Internal use Technical Manual PI – V1.2 MA-005 Rev. 1 16/01/2004 Page VI - 7...