y25-029-0 training for o&m manual for excitaion system

8/12/2019 Y25-029-0 Training for O&M Manual for Excitaion System

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Sr.: REV.: Description Drawing No. Date Remark

CLIENTE:

ELLICA MONTE REDONDO S.A.

CONTRACTOR:

DONGFANG ELECTRIC CORPOATION LTD.

PROJECT: LAJA HYDROELECTRIC PLANT PROJECT, CHILE

DRAWING TITLE

NES5100 Excitation System

Operation and Maintenance Manualfor Chile LAJA Hydroelectric Plant

DESIGNED Huang Weiping 2012-5-13 Manufacture

CHECKED Zhu Hongchao 2012-5-13NARI Technology Development Ltd.

Company

TRANSLATED

APPROVED He Qianchao 2012-5-13DEC file No: Y25 -029-0

SCALE AS SHOWN Pages 32 (Inc. this page)


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Catalogue

1 Purpose...........................................................................................................................................2

2 Applicable Position ........................................................................................................................2

3 Brief Introduction of NARI excitation system...............................................................................2

3.1 Introduction.........................................................................................................................2

3.2 Hardware.............................................................................................................................2

3.2.1 The components of NES5100 excitation system:.....................................................2

3.2.2 NES5100 excitation system includes five cabinets:.................................................2

3.3 Software ..............................................................................................................................3

4 Excitation system configuration.....................................................................................................3

4.1 NES5100 AVR configuration:..........................................................................................4

4.1.1 AVR Card .................................................................................................................4

4.1.2 Power Supply ...........................................................................................................6

4.1.3 AVR control mode....................................................................................................74.1.4 Protection .................................................................................................................8

4.2 SCR cabinet configuration ..................................................................................................9

4.2.1 SCR bridge...............................................................................................................9

4.2.2 synchronizing transformer .......................................................................................9

4.3 Deexcitation OVP cabinet configuration .......................................................................10

5 Excitation system start, stop and operation..................................................................................10

5.1 Local operation .................................................................................................................10

5.1.1 AVR button instruction...........................................................................................10

5.1.2 HMI software .........................................................................................................12

5.2 Excitation checking before starting...................................................................................16

5.3 Start excitation ..................................................................................................................16

5.3.1 AVR mode selection ...............................................................................................16

5.3.2 Main AVR controller selection ...............................................................................16

5.3.3 Start excitation .......................................................................................................16

5.4 On line operation...............................................................................................................17

5.5 Stop excitation...................................................................................................................17

5.6 Inspection and notice items during AVR operation ...........................................................17

6 Maintenance and Troubleshooting ...............................................................................................18

6.1 Maintenance......................................................................................................................186.1.1 Introduction............................................................................................................18

6.1.2 Working Condition during Operation ....................................................................18

6.1.3 Quarterly Maintenance...........................................................................................19

6.1.4 Yearly Maintenance (During Planned Shutdown)..................................................19

6.2 How to Find Failure ..........................................................................................................20

6.3 Summary of Failure Signals..............................................................................................20

6.4 Troubleshooting ................................................................................................................22

6.4.1 Principles for Troubleshooting...............................................................................22

6.4.2 Guideline for Replacement of Boards....................................................................22

6.4.3 Troubleshooting .....................................................................................................23


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NES5100 Excitation System

Operation and Maintenance Manual

1 Purpose

This Manual described the operation procedure of NES5100 regulator, introducedsafety points for attention and operation features of regulator, which can instructtechnicians for successful execution of regulator operation and maintenance.

2 Applicable PositionsOperation technicians and maintenance technicians

3 Brief Introduction of NARI excitation system

3.1 Introduction

The NES5100 excitation system from China NARI is new generation digitalexcitation system in the world. The system provides DC field current to controlgenerator voltage and keep it constant. The AC power source is from excitationtransformer. The generator voltage and current all go to AVR as signal feedback.

The field voltage and current are target controlled values. NES5100 excitationsystem consists of signal measurement module, control module, SCR (Siliconcontrolled rectifier) module, protection loop and etc.. In the excitation system, theinput current from excitation transformer goes to three phase full-controlled SCRBridge. SCR Bridge creates and controls the output DC field current. For loadrejection and deexcitation, excitation system can provide rapid response.Excitation system control SCR Bridge by firing pulse. The firing pulse created bydigital controller in AVR. AVR has two redundant channels as channel A and

channel B. Two channels have own firing loop and auto following function,guarantee smooth switching between two channels.

3.2 Hardware

3.2.1 The components of NES5100 excitation system:

Controller and I/O module Signal measurement module HMI


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Power supply module RCR module R/C absorption module Deexcitation protection module

Electrical breakers

3.2.2 NES5100 excitation system includes five cabinets:

One AVR control (NES5100 voltage regulator) cabinet, for excitation control,monitoring and I/O communication.

Two Rectifier cabinets, consists of SCR module, electrical breakers, fan andSynchronizing transformer etc.. . SCR module consists of SCR bridges, RC

absorption loop and pulse loop.

One Deexcitation OVP cabinet, for protecting generator and excitation

system. One excitation transformer, for offering power to SCR module.

3.3 Software

NES5100 uses ARM as microprocessor to execute control code. The softwareconsists of all required system function block. The definition of function block andparameter configuration is all running in read only memory, variants are allrunning in RAM.The application software of NES5100 which is NES5100 HMI software isinstalled in HMI computer. AVRs function, parameters can be configured byNES5100 HMI software. The various function blocks have specific function, forexample, logic gate, PID controller, parameter sampling. There are five controlmode can be selected: Auto mode (voltage loop), Manual mode (current loop),Power Factor mode, Var mode and Open loop (fixed angle). There is protectionfunction block includes over excitation limit, under excitation limit, V/Hz limit andetc.. During the normal operation, the function block can be checked by NES5100HMI software, the AVR status also can be monitored by HMI.

4 Excitation system configurationsExcitation system: For Self-shunt excitation system


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Excitation system type NARI NES5100 digital AVR.

4.1 NES5100 AVR configuration:

4.1.1 AVR Card

NES5100 AVR has two independent and redundant controller as channel A andchannel B. Two channels have own firing loop and auto following function,guarantee smooth switching between two channels. Each channel has 8pluggable cards.

Figure 4-1: 8 cards in one channel

See Table 4-1 for name of boards:

Board

No.Board name

Function

EX01Pulse powerboard

EX01 pulse power board has double power source:

AC220V (or AC110V), DC220V (or DC110V)

input;

+24v output for pulse amplification board

EX02System powerboard

EX02 system power board has double power source:

AC220V (or AC110V), DC220V (or DC110V)

input;

+5V 12V and +24V output for digital board;EX03 CPU board EX03 CPU board is the central control board, with the


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Fig4-2 AVR Front View

Q1 is AC power supply switch of Channel A, Q2 is DC power switch of Channel A, Q3 is AC power supply switch of Channel B, Q4 is DC power supply switch of Channel B, Q5 is AC power supply switch of industrial computer, Q6 is DC power supply switch of DI relay, Q11 is AC power supply switch of Aux circuit, Q12 is AC power supply switch of Heater, Q21, Q22 is DC power supply switch of Control circuit, QM1, QM2, QM3, QM4 is AC power supply switch of Fan, SA1 is +24v power switch of the first rectifiers pulse,

SA2 is +24v power switch of the second rectifiers pulse.


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4.1.3 AVR control mode

There are 5 AVR control mode. Each one can be selected as required.

Auto Mode AVR Use generator voltage as target value, adjustand keep generator voltage constant.

Manual Mode FCR Use excitation current as target value, adjustand keep excitation current constant.

Power Factor Mode Use power factor as target value, adjust andkeep power factor constant.

Var Mode Use Mvar as target value, adjust and keepMvar constant

Fixed angle (Openloop)

Use firing angle as target value.This mode only for commissioning and onlycan be set in HMI.

4.1.4 Protection

NES5100 have a lot of protection function, main protection functions are listed asfollows:

Under excitation limit(UEL)

If the MVar exceed the UEL limit line in PQdiagram, The UEL will be active in 0.06s,generator voltage will be raise until MVarreturn to normal scope.The UEL set point is set according togenerator PQ character.

Over excitation limit(OEL)

If the MVar exceed the OEL limit line in PQdiagram, The OEL will be active in 5s,generator voltage will be lower until MVarreturn to normal scope.The OEL setpoint is set according togenerator PQ character.

V/Hz limit(VEL)

If the V/Hz ratio exceeds the limit line, TheVEL will be active in 0.06s, AVR will controlV/Hz within 1.06.

PT disconnectIf main channel report PT disconnect, mainchannel will switch to following channel, Automode will switch to Manual mode in main


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channel.

Forced Excitation limit(FEL)

Forced excitation limit allow AVR keepworking in short time when excitation currentis twice as much as rating. The more

excitation current the less time keepexcitation.

No-load Over Voltageprotection

In no-load operation, the generator voltagemore than 130% rating, protection will beactive in 0.06s. Excitation will be stopimmediately.

Low frequency andloss excitationprotection

AVR detect generator voltage and frequency.If frequency is too low to exceed limit, Lowfrequency and loss excitation protection willbe active.

4.2 Rectifier cabinet configuration

4.2.1 Thyristor bridge

Circuit breaker:3-pole separate AC circuit breaker and 2-pole separate DCcircuit breaker.

Power source: excitation transformer , 420VAC 50Hz three phases output: 210V DC voltage,710A DC current

2*100% Thyristor bridge Two redundant bridge (cabinet) with RC absorption

module. If one bridge fault, the other one can keep AVR normal working. Pulse transformers: used for transforming spring pulse.

4.2.2 Synchronizing transformer

Power source: excitation transformer , 420VAC 50Hz three phases

Transformer model: 200VA,50Hz,650V/150V,Y/D-1.output rating: 97VAC,three phases.

Transformers: Two redundant transformers, one is used for channel A, andthe other one for channel B. If one with fault, it will not influence the othernormal channel.


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4.3 Deexcitation OVP cabinet configuration

Circuit breaker (4 pole): disconnect the rectifier and rotor. Non-linear resistor: the deexcitation fleetly equipment.

Initial excitation option an initial excitation is necessary which is activated for

around 410 seconds when the normal excitation is activated. The initial

excitation can be fed from the power station battery or from the 3AC

400V station service switchgear. Control circuit: this circuit is major used for controlling Breaker.

5 Excitation system start, stop and operation

5.1 Local operation

5.1.1 AVR button instruction

The basic local control of AVR by buttons in front of AVR panel:


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Fig 5-1 AVR front view

Table5-1 AVR buttons :

Button Function Note

S1 Excitation Raise

To raise generator voltage in Auto mode;To raise rotor current in Manual mode;To raise PF in PF mode;To raise MVar in Var mode.


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5.1.2 HMI software

NES5100 HMI software is developed by NARI company. The software installed inHMI computer.We can do following thing through AVR HMI:

Reading electrical values of generator, field and bus line Reading status of excitation system Reading Error log and locate fault and do diagnosis.

AVR commissioning Setting AVR parameters

Fig5-2 AVR HMI display

S2: Excitation Lower

To lower generator voltage in Auto mode;To lower rotor current in Manual mode;To lower PF in PF mode;To lower MVar in Var mode.

S3:

Excitation On To start excitation to build generator voltage to

100%.

S4: Excitation OffTo stop excitation to lower generator voltageto 0.

QK1: PSS Enable Enable PSS function (Optional)

QK2: A/B ActiveSwitch main channel between channel A andB.

QK3: HMI Enable Power switch of HMI computer


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In the top of the window shows state indication and parameter readings. Left ofthe window is optional tag. Center of the window is topology of excitation system.

Table 5-2 HMI

Function Icon Indication Note

Channel

Normal (Green)

Communication is normal

COMUNICATION

STATE Channel Fault

(Red)

Communication with fault

Waiting Excitation is offEXCITATION

STATE No-load/On-line Excitation is on

Voltage-loop Auto Mode (AVR)

Current-loop Manual Mode FCR

PF Power Factor Mode

Var Var Mode

1

State

Indication

CONTROL

MODE

Fixed-angle Open-loop Mode

TRIGGER

ANGLE

Degree Normal range 20 -150 .

POWER

FACTOR

Displays the power factor

of generator.

GENERATOR

FREQUENCY

Hz Displays the measured

value of terminal

frequency of generator.

STATOR

VOLTAGE

% Displays the measured

value of generator unit

stator voltage (PT).

VOLTAGE

SETTING

% Displays the given value

of generator unit stator

voltage.

2

ParametersReading

ACTIVE POWER

MW Displays the measured

value of the active power

of generator.


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ROTOR

CURRENT

A Displays the measured

value of generator rotor

current.

CURRENT

SETTING

A Displays the given value

of generator rotor current.

REACTIVE

POWER

MVar Indicates the measured

value of the reactive

power of generator.

In system topology, there

are the schematic

diagram of system

connection, and visual

graphic marks. If a graphic

clicked is highlighted or

brightened, it shows that

the internal related data of

this graphic may be

observed.

What displayed in the

parameter window on theinterface is the parameter

run at the present section.

Here, the parameter is

only displayed, but not to

be revised.

We can set all parameters

in setting window.

Check the fault history in

Err Log. Any date can be

checked in history.

The list shows limit, alarm

and fault.

3

Function

Block

MONITER UNIT

Exit the HMI software.


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5.2 Excitation checking before starting

1. Verify insulation breaker of PT and CT, check the PT and CT terminal is wellconnected.

2. Turn all AVR power breakers on, check the voltage is OK.3. Verify AVR cards with no fault, HMI display is normal, communication

between DCS and AVR is OK.4. Open and close field breaker once time to verify field breaker is normal

5.3 Start excitation

NES5100 can be started from local or remote. Normally AVR should be startedfrom remote, while local operation mode is usually used for test .

5.3.1 AVR mode selection

1) Auto mode (Voltage-loop). AVR normal running all use Auto mode.2) Manual mode (Current-loop). Not recommend to use this mode in normalrunning. If AVR PT failure is detected, will switch from Auto mode to Manual mode

3 Var mode (VAR control). If adjustment is over, may cause over excitation and

under excitation. So not recommend to use this mode in normal running

4 Power Factor mode. Normally dont use this mode, if use this mode, voltage of

generator and bus line should be monitored to avoid over or under voltage.Operator also can change AVR mode manually from DCS AVR control window.

5.3.2 Main AVR controller selection

When AVR is running, Channel A and B are redundant. When channel A work asmaster, channel B will be following as backup. If Channel A is down, mainchannel will switch to channel B smoothly. Operator also can change mainchannel manually at site. See Fig 5-1

5.3.3 Start excitation

1. Close circuit breaker QS1, QS2, QS3, QS4, and field circuit breaker FMK.2. After the generator achieves the rating speed, operate excitation on button


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at site or DCS, the generator voltage will be raised to the reference value.3. Operator can adjust generator voltage and MVar by Raise and Lower button

manually at site or DCS as required.

5.4 On l ine operation

Operator can adjust MVar though Raise and Lower button at site or DCS

5.5 Stop excitation

Whatever AVR work in Auto mode or Manual mode, AVR can be stopped asnormal by following step:1. Press excitation off button from Local (AVR) or Remote (DCS).2. The generator voltage will drop down in a short time.3. After generator voltage achieves zero, operator can open field circuit breaker

FMK.

Emergency stop:Operator can open field circuit breaker FMK directly when emergency, AVR start

de-excitation, lower generator voltage to zero immediately.

5.6 Inspection and notice items during AVR operation

1. Check temperature in excitation system room, the temperature should be

under 40 , air conditioner is normal.

2. Check AVR status, no alarm, no abnormal displayed on AVR cards.

3. Operator should monitor generator voltage and MVar very carefully. Adjustgenerator voltage and MVar in time to avoid over voltage or under voltage.

4. If AVR report alarm, the problem should be solved in time. If cause is not clear,check in local, or contact technical department.

5. AVR can reset alarm itself if problem is cleared away. Error history is saved inErr Log. The curve can be saved automatically for analysis.


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6.1.3 Quarterly Maintenance

Quarterly maintenance is primarily visual check.

Comparison between measured value (under working condition ): Observe

measured value of two channels and compare the measured value with displayvalue indicated by control room; engineer should compare measured value ofvoltage and reactive power with their display value. If no reference value isavailable for comparison with measured value, engineer must use previouslymeasured value to estimate accuracy of measured value .

Detect redundant regulator circuit (under working condition or )

Engineer can change set value of regulator by increasing or reducing excitation;standby channel should automatically track operating channel; engineer mayobserve tracking results through monitoring interface.

Switch between operating mode or operating channel (under working

condition )

Engineer should perform switch between operating modes or operating channels;field current and generator stator voltage should not obviously change. This alsoverifies whether pulse trigger circuit is normal.If switch is performed stably, then all standby circuits can be considered normal.On the contrary, if switch between channels cause significant change in workingcondition, then engineer should find the reason for failure by referring to FailureFinder.

After test is completed, operator should switch manual mode

into automatic mode.

6.1.4 Yearly Maintenance During Planned Shutdown)

After removing dust, tightening terminal screw and detecting insulation, performthe following check:

Calibrate external control signals (under working condition ): find input

signal source and simulate contact action according to drawings; see if circuit isnormal by observing indicator lamp on digital board, relevant interface in


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Synchronous frequency B-phase

failure

Synchronous frequency C-phase

failureSynchronous phase A-phase failure

Synchronous phase B-phase failure Synchronous phase

failureSynchronous phase C-phase failure

Synchronous phase

sequence failureSynchronous phase sequence failure

+A-phase pulse alarm

-C-phase pulse alarm

+B-phase pulse alarm

-A-phase pulse alarm

+C-phase pulse alarm

-B-phase pulse alarm

Pulse read-back failure

Pulse failure

Pulse count failure

Ethernet communication failure

485 communication failure

UART communication failure

CAN1 communication failure

Communication failure

CAN2 communication failure

A/D failure

FPGA failure

SPI failure

TC2 interrupt failure



Main task failure

EX03 board hardware

and software failure

TC4 task failure


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UART task failure

Update task failure

USB task failure

Power source detection failure

Field flashing failure

PT line broken failure

No-load load switch close failure

Loaded load switch open failure

Electrical circuit failure

and functional failure

Power cabinet failure

Table 6-1: Failure Signals Note: indicates that this channel can be detected.

6.4 Troubleshooting

Repair engineers must follow safety instruction contained in

Chapter 1.

6.4.1 Principles for Troubleshooting

Under most circumstances, user can locate failure and perform timelytroubleshooting by reading failure information recorded in failure log module inmonitoring software.If failure in hardware or software of excitation regulator is not caused by anexternal reason, operator can attempt to restart excitation regulator. If operatorcan remove failure by restarting excitation regulator, then system will work again.If operator can not remove failure by doing so and failure signal keeps appearing,then operator may attempt to replace board.

6.4.2 Guideline for Replacement of Boards

If you intend to replace board, you must be aware that the board is printed circuit

board, and that electrostatic discharge from CMOS components may causepersonal injury.


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Rubbing synthetic fibre may result in electrostatic discharge.

When operator operates circuit board, operator must follow the followinginstruction in order to avoid electrostatic discharge:

Mount antistatic rubber on test bed beside the cabinet, and connect ground

wire to the framework of the cabinet.

Touch a paint-free space in the cabinet before touching circuit board so that

you can perform electrostatic discharge.

Store the standby board in their original package.

Please carefully read the abovementioned instructions before replacing boards.Procedure for replacement is as follows:1. Disconnect the electrical power to regulator;2. Pull out board that needs replacing with special tools;3. Disassemble circuit board;4. Make sure that model of new circuit board is the same as faulted circuit boardor make sure that new circuit board is compatible with faulted circuit board;5. Compare identification code of jumper, components (variable resistance,built-in program or data chip with that of faulted board and make sure that theyare the same; otherwise you can not ensure that new circuit board worksnormally.

Our spare parts have been tested in our factory; jumper has been

set and program has been downloaded; operator can directly

replace worn parts with our spare parts.

6.4.3 Troubleshooting

This section tells user how to remove failure listed in Table 7-1. User can performtroubleshooting by using the methods described in Troubleshooting or completeFailure Description Form and send it to Electrical Control Branch, NARI GroupCorporation so that technicians can analyze the location of failure.

6.4.3.1 Stator Frequency Failure


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Failure inquiry

During the commissioning or operation of excitation regulator, if alarm signalappears or alarm indicator lamp on EX03 board flashes, operator can make an

inquiry of the type of failure by reading Failure Log in monitoring software.If a record of Stator frequency failure is available, check to see if it is Statorfrequency * phase failure and determine whether the alarm is given by aregulator or not.

Troubleshooting procedure is as follows:

Check to see if voltage source meets requirements in the process of

commissioning, and if voltage signal is correct by using test device to test voltageat terminal or other locations;

If voltage source signal is correct, then operator must check EX04 board and

EX03 board; If a set of regulator fails, operator may replace EX04 board andEX03 board of both regulators so as to determine which board fails;

6.4.3.2 Stator Phase Failure

Failure inquiry

During the commissioning or operation of excitation regulator, if alarm signalappears or alarm indicator lamp on EX03 board flashes, operator can make aninquiry of the type of failure by reading Failure Log in monitoring software.If a record of Stator phase failure is available, check to see if it is Stator phase *phase failure and determine whether the alarm is given by a regulator or not.

Procedure for troubleshooting is as follows:

Open oscilloscope in monitoring software, and check to see if waveform of

Stator voltage signal is correct and if Stator voltage phase is normal;

If waveform of Stator voltage signal is incorrect, check voltage signal at

voltage terminal 1001 according to drawings, and check to see if wiring is corrector terminal is loosened;

If wiring is correct, check to see if voltage source meets requirements in the

process of commissioning; Check to see if voltage signal is correct by using testdevice to test voltage at terminal or other locations in the process of operation;


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EX03 board; If a set of regulator fails, operator may replace EX04 board andEX03 board of both regulators so as to check to see which board fails;

If oscilloscope module indicates that waveform of Stator voltage is correct,

operator should check to see which board fails by step ;

6.4.3.3 Synchronous Frequency Failure

Failure inquiry

During the commissioning or operation of excitation regulator, if alarm signalappears or alarm indicator lamp on EX03 board flashes, operator can make an

inquiry of the type of failure by reading Failure Log in monitoring software.If a record of synchronous frequency failure is available, check to see if it issynchronous frequency * phase failure and determine whether the alarm isgiven by a regulator or not.


Check to see if synchronous voltage source meets requirements in the

process of commissioning; Check to see if voltage signal is correct by using testdevice to test voltage at terminal or other locations in the process of operation;


EX03 board; If a set of regulator fails, operator may replace EX05 board andEX03 board of both regulators so as to check to see which board fails;

6.4.3.4 Synchronous Frequency Phase Failure

Failure inquiryDuring the commissioning or operation of excitation regulator, if alarm signalappears or alarm indicator lamp on EX03 board flashes, operator can make aninquiry of the type of failure by reading Failure Log in monitoring software.If a record of synchronous phase failure is available, check to see if it issynchronous phase * phase failure and determine whether the alarm is given bya regulator or not.




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synchronous voltage signal is correct and if synchronous voltage phase iscorrect;

If waveform of synchronous voltage signal is incorrect, check voltage signal at

synchronous voltage terminal 1005 according to drawings, and check to see ifwiring is correct or terminal is loosened; And then check to see if signal terminalof synchronous transformer is loosened;

If wiring is correct, check to see if synchronous voltage source meets

requirements in the process of commissioning; Check to see if voltage signal iscorrect by using test device to test voltage at terminal or other locations in theprocess of operation;

If synchronous voltage source signal is correct, then operator must check

EX05 board and EX03 board; If a set of regulator fails, operator may replaceEX05 board and EX03 board of both regulators so as to check to see which boardfails;

If oscilloscope module indicates that waveform of synchronous voltage is

correct, operator should check to see which board fails by step ;

6.4.3.5 Synchronous Phase Sequence Failure

Failure inquiry

During the commissioning or operation of excitation regulator, if alarm signalappears or alarm indicator lamp on EX03 board flashes, operator can make aninquiry of the type of failure by reading Failure Log in monitoring software.Correct value of synchronous phase sequence should be 635H.

If a record of synchronous phase sequence failure is available, check to see if aset of regulator fails or both sets of regulators fail.



synchronous voltage signal is correct and if synchronous voltage phase iscorrect.

If waveform of synchronous voltage signal is incorrect, check voltage signal atsynchronous voltage terminal 1005 according to drawings, and check to see if


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wiring is correct; And then check to see if signal terminal of synchronoustransformer inside power cabinet is loosened;

If wiring is correct, check to see if synchronous voltage source meets

requirements in the process of commissioning; Check to see if voltage signal iscorrect by using test device to test voltage at terminal or other locations in theprocess of operation;

If synchronous voltage source signal is correct, then operator must check

EX05 board and EX03 board; If a set of regulator fails, operator may replaceEX05 board and EX03 board of both regulators so as to check to see which boardfails;

If oscilloscope module indicates that waveform of synchronous voltage is

correct, operator should check to see which board fails by step ;

6.4.3.6 Pulse Signal Alarm

Failure inquiry

During the commissioning or operation of excitation regulator, if alarm signal

appears or alarm indicator lamp on EX03 board flashes, operator can make aninquiry of the type of failure by reading Failure Log in monitoring software.If a record of pulse signal alarm is available, check to see if a set of regulator failsor both sets of regulators fail.


Measure value of small pulse by opening square waveform and pulse

detection in monitoring software; correct pulse value of various kinds ofphase is following:

+A -A +B -B +C -C

130 40 96 06 192 12

If value of phase pulse is incorrect, engineer should check to see if signal

wiring is correct or loosened;

If wiring circuit is correct, engineer should check to see if EX03 board or EX08

board fails and determine the source of failure by replacing board one by one.


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6.4.3.7 Pulse Read-back Failure

Failure inquiry

During the commissioning or operation of excitation regulator, if alarm signal

appears or alarm indicator lamp on EX03 board flashes, operator can make aninquiry of the type of failure by reading Failure Log in monitoring software.If a record of pulse read-back failure is available, check to see if a set of regulatorfails or both sets of regulators fail.The principle for pulse read-back detection is as follows: pulse from EX08 boardflows through pulse read-back circuit and is sent to FPGA after level translation;FPGA checks to see if pulse read-back is correct by judging whether pulsereturned is identical with pulse sent.


Engineer should check to see if EX03 board or EX08 board fails, and if the failurecan be removed by resetting EX03 board.If engineer fails to remove the failure, he may determine the source of failure byreplacing board one by one.

6.4.3.8 Pulse Count Failure

Failure inquiry

During the commissioning or operation of excitation regulator, if alarm signalappears or alarm indicator lamp on EX03 board flashes, operator can make aninquiry of the type of failure by reading Failure Log in monitoring software.If a record of pulse count failure is available, check to see if a set of regulator failsor both sets of regulators fail.The principle for pulse count is as follows: pulse from EX08 board flows through

pulse read-back circuit and is sent to FPGA after level translation. FPGA checksto see if pulse count is correct by judging whether pulse returned is identical withpulse sent.


Engineer should check to see if EX03 board or EX08 board fails, and if the failurecan be removed by resetting EX03 board.If the failure can not be removed, then determine the source of failure by

replacing board one by one.


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A/D failure

FPGA failure

SPI failure




Main task failure

TC4 task failure

UART task failure

Update task failureUSB task failure E

X 0 3 b o a r d

h a r

d w a r e a n

d s o

f t w a r e

f a i l u r e

Power source detection failure

Table 6-3: EX03 Board Hardware and Software Failure List


Engineer should check EX03 and check to see if the failure can be removed byresetting EX03 board.If the failure can not be removed, engineer should determine the source of failureby replacing board one by one.

6.4.3.12 PT Disconnected Failure

Failure inquiry

During the commissioning or operation of excitation regulator, if PTDisconnected Failure alarm signal appears or alarm indicator lamp on EX03board flashes, operator can make an inquiry of the type of failure by readingFailure Log in monitoring software.

PT Disconnected signal means that PT1 used by A channel or PT2 used by Bchannel fails.If failure in current operating channel happens, the regulator will automaticallyactivate standby channel.


PT failure is usually caused by PT three-phase imbalance. If PT failure


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happens to A channel, engineer should check to see if PT1 three-phase voltageat terminal block is balanced;

If PT1 three-phase voltage at terminal block is unbalanced, then PT

Disconnected failure may be caused by external reason; Engineer should checkto see PT1 high side fuse is working normally or terminal connection is loosened;

If PT three-phase voltage is balanced, then PT Disconnected failure may be

caused by internal reason. Engineer should check to see if internal connection ofPT1 signal is loosened or check EX04 board and EX03 board.

Engineer should check EX04 board and EX03 board; if a set of regulator fails,

then engineer can determine which board fails by replacing EX04 board andEX03 board of both sets of regulators one by one;If PT failure happens to B channel, remove the failure by following theabovementioned steps.6.4.3.13 Power Cabinet Failure

Failure inquiry

During the commissioning or operation of excitation regulator, if power cabinetfailure alarm signal appears or alarm indicator lamp on EX03 board flashes,operator can inquire about which power cabinet fails by reading Failure Log inmonitoring software.


Power cabinet failure comprises power cabinet blower failure, power maincircuit fuse break, power cabinet resistance-capacitance absorption fuse break.Specific form of power cabinet failure depends on failure signal setting of powercabinet.Check to see if failure indicator lamp on power cabinet flashes, and checkrelevant circuit. If power cabinet failure does happen, check relevant digital boardaccording to the design of drawings; if digital board is failure-free, operator shouldcheck EX03 board.

If engineer fails to remove the failure or there is a lack of spare

parts, please call us at our hot line!

y25-029-0 training for o&m manual for excitaion system

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