Operation Procedure of 500kv Subtation (HTOM-E-01)

Revision: Language: Page:

0 En 1/73 HTOM-E-01

Dept:

HEPE Harbin Huitong Electric Power Engineering Co., Ltd.File no.:

Project: Plant section:

747MW GUDDU Combined Cycle Power Project O&M ManualPrepared Checked: Approved:

Form No.:

HTF-0 Operation & Maintenance ManualDate:

2014.3 Operation Manual

747MW (Gross) Combined Cycle Power Plant

Project At GUDDU

Operation & Maintenance Manual

Volume AOperation Procedure of 500kv

Substation

Department：O&M

Content Page：2/73

HTOM-E-01 Rev . O Issue Date: 2013/11/15 2/73

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Operation Procedure of500kV Substation

Page：3/73

Content

CONTENT........................................................................................................3

1 SWITCHING OPERATION........................................................................8

1.1 Normal device state.........................................................................................................8

1.2 General requirements of switching operation.........................................................9

1.3 Operation summarize....................................................................................................10

1.4 reactive voltage regulation..........................................................................................14

2 500KVTRANSFORMER..........................................................................14

2.1 500KV transformer summarizing...............................................................................14

2.2 Inspection of 500kV transformer...............................................................................15

2.3 500KV transformer acceptance check before put into operation.....................17

2.4 500kV transformer running and operation..............................................................18

2.5 500KV transformer operation considerations........................................................20

2.6 500kV transformer abnormal and accident treatment.........................................21

3 HIGH SF6 CB..........................................................................................25

3.1 Inspection of CB.............................................................................................................25

3.2 The circuit breaker acceptance after the overhaul...............................................26

3.3 Operation and control of circuit breaker.................................................................27


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3.4 CB operation consideration items............................................................................27

3.5 CB abnormal treatment................................................................................................27

4 VOLTAGE AND CURRENT TRANSFORMER........................................31

4.1 Summarizing...................................................................................................................31

4.2 inspection of voltage and current transformer......................................................31

4.3 The acceptance items after transformer repair.....................................................32

4.4 The current and voltage transformer operation....................................................32

4.5 The current and voltage transformer operation consideration matters.........33

4.6 The current and voltage abnormal treatment.........................................................33

5 HIGH VOLTAGE ISOLATOR..................................................................35

5.1 Summarizing...................................................................................................................35

5.2 Isolator inspection.........................................................................................................35

5.3 The isolator acceptance after repair.........................................................................36

5.4 Isolator operation...........................................................................................................36

5.5 Isolator operation consideration matters................................................................37

5.6 Isolator abnormal treatment........................................................................................37

6 500KV REACTOR...................................................................................38

6.1 Summarizing...................................................................................................................38

6.2 High voltage reactor......................................................................................................38

6.3 High reactor operation..................................................................................................39

6.4 Reactor operation consideration matters...............................................................40

6.5 High voltage reactor abnormal and accident treatment......................................40


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7 POWER TRAPPER.................................................................................43

7.1 Trapper inspection........................................................................................................43

8 BUSBAR 、FRAMEWORK.....................................................................43

8.1 Summarizing...................................................................................................................43

8.2 Inspection........................................................................................................................44

9 LIGHTNING PROTECTION AND EARTH DEVICE................................44

9.1 Summarizing...................................................................................................................44

9.2 Inspection........................................................................................................................45

9.3 Acceptance item after the overhaul..........................................................................45

9.4 Operation consideration matters...............................................................................46

10 AC SYSTEM IN SUBSTATION.........................................................46

10.1 System configure and operation...............................................................................46

10.2 Station system routine inspection............................................................................47

10.3 Operation..........................................................................................................................48


10.5 Abnormal and accident treatment.............................................................................49

11 SUBSTATION DC SYSTEM..............................................................50

11.1 System configure and operation mode....................................................................50

11.2 Operating provision......................................................................................................50

11.3 DC grounding treatment..............................................................................................51

11.4 Net control system operation procedure................................................................52

12 ACCIDENT TREATMENT.................................................................54


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12.1 General principle of accident treatment..................................................................54

12.2 Line accident treatment................................................................................................55

12.3 Buabar fault and loss treatment................................................................................56

12.4 Resonance overvoltage treatment............................................................................56

13 OPERATION AND MANAGEMENT OF GENERAL RELAY PROTECTION AND AUTOMATIC SAFETY DEVICE...................................57

13.1 Management provisions...............................................................................................57

13.2 Normal inspection..........................................................................................................59

13.3 Operating instructions..................................................................................................60

13.4 Abnormal operation treatment...................................................................................62

14 500KV MAIN TRANSFORMER PROTECTION................................62

14.1 Summarizing...................................................................................................................62

14.2 Panel introducing...........................................................................................................63

14.3 Normal operation...........................................................................................................64

15 HIGH VOLTAGE REACTOR PROTECTION....................................64

15.1 GE reactor protection...................................................................................................64

15.2 panel introduction..........................................................................................................65



15.5 Abnormal judgment and treatment...........................................................................66

16 500KV SHORT LEAD PROTECTION...............................................66

16.1 Summarizing...................................................................................................................66

16.2 Panel introduction.........................................................................................................67


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16.5 Abnormal judgment and treatment...........................................................................68

17 500KV FAULT RECORDER.............................................................68

17.1 Summarizing...................................................................................................................68

17.2 Fault recorder operation provision...........................................................................68

17.3 fault recorder signal......................................................................................................69


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1 Switching operation

1.1 Normal device state

1.1.1Electrical device state as below ：

1 、 Device “running status”: isolator is closed , CB is closed , all electrical circuit is

powered (including PT、arrestor )

2、Device “hot standby status”: isolator is closed , CB is opened .electrical circuit without

CB such as busbar 、PT and so on.

3、Device “Cold standby status”: isolator is opened , CB is opened .

1 ） “ CB cold standby status” take the fuse down for PT related with CB, open the isolator.

2） “Line cold standby status” take the fuse down for PT related with line, open the isolator.

3） “Line cold standby status” take the fuse down for PT related with busbar, open the isolator.

4 ） “ Cold standby status” isolates PT and arrestor with isolator, PT without upside isolator will take down low fuse.

4、 “Maintenance status” related CB and isolator will switch off , connect the ground lead or close earth switch (hang working brand , install temporary barrier).according to

difference device , so called “CB maintenances” or“line maintenances”

1） “CB maintenance” related CB and isolator will switch off, PT switch between CB and line isolator be pulled down .take off CB fuse , connect the ground line (or close

earth switch).

2） “ line maintenance” line CB and isolator will switch off, PT switch between CB and line isolator be pulled down .take off CB fuse , connect the ground line (or close earth

switch).

3） “ transformer maintenance”connect the ground line at trans each side , power off trans cold power supply.


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4）“busbar maintenance” transfer busbar cold standby status to maintenance status , connect the ground line (or close earth switch).

5、“Charging status”energize the equipment without load current , ignore litter excitation current.

1.1.2Equipment status changing be permitted by the center dispatch.

1.1.3Secondary circuit work after safety measure be done by operator at running

equipment.

Close and open CB when CB near busbar be repaired at3/2 configuration, quit CT link

related busbar protection before primary circuit loop closing and put CT link into service

before energizing. Protection engineer take charge CT link when CT link has test link,

operation be in charge of CT link when CT link has test link.

1.2 General requirements of switching operation

1.2.1Items as list not be filled in PTW(permit to work), but write down operational log in

details

1、Accident emergency processing

2 、 Single operation, such as Close and open CB, put low reactor or capacitor into service.

3、Main transformer on-load taps changer single operation

1.2.2 Except for above items, all operations must fill in PTW, including AC and DC

operation 、verification of live part 、connect or disconnect ground lead 、 take down control circuit fuse and so on .

1.2.3 Operator must be done by himself below items

1、Low voltage power supply (AC and DC )operation (not affected primary and secondary equipment normal running)

2、Regular switchover test

3 、 Communication fail or accident handling for doing harm to persons and equipment(report to shift chief operator at once)

1.2.4 During normal switching operation, stop to operate when accident or abnormal

condition happen , handle the accident at once ,then report to dispatcher .

1.2.5 Operator in duty must obey the dispatcher order, not allow refusing or delaying the

work. But mistaken operation task or obvious harm persons(equipment) order will be

refused, report correct suggestions to shift chief operator and leader.


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1.2.6 Electrical equipment protection interlock not be permitted to unlock, if be required

(accident deal 、abnormal operation and so on ),

Protection interlock must be unlock under the authorization of the main shift at the

substation or shift chief operator) .

1.2.7Avoid electrical operation at as follow stage

1、Shifting of duty

2、power grid connection abnormal

3、system peak load

4、thunderstorm 、high wind and so on

5、The related line power load exceed steady limit.

6、Grid accident happen

7、Grid special requirements

1.3 Operation summarize

1.3.1 3/2 connection characteristic

500KV substation take on collecting power load 、reassignment load、 transmitting power and so on. So it is important position in high voltage transmission grid .now 500kv

substation have double busbar with four sections and 3/2 CB connection in the word .

operation advantage in 3/2 CB connection is obvious gradually, so at present 3/2 CB

connection is widely used,

In our site 3/2 CB connection is used, be composed of 3 completed loop , three units

connect to the substation by 340MVA three phase duplex winding transformer, every

generator outlet has GCB. 3 line are placed from west side to east side , its name is

GUDDU、MULTAN、MUZAFFAR GARH.

1、main mode of operation

1）Normal mode of operation.: The two group bus running at the same time, all circuit

breakers and disconnecting switches are closed;

2 ） Power lines: Circuit breakers and string running mode. The power circuit,

considering the reliability of power supply, the maintenance of the line often circuit

breaker closes, will overhaul the line side isolation switch;

3 ） Circuit breaker maintenance operation mode, if any one circuit breaker

maintenance, only the circuit breaker open and then two side isolators open;


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4 ） Bus running mode of maintenance. Disconnect bus circuit breaker and isolating

switch sides. This is equivalent to the single bus allows, low reliability, so should try

to shorten the running time of single busbar

2 、The advantages and disadvantages of 3/2 connection

1）Advantages

A、The high reliability of power supply. Each loop has two sets of circuit breaker power

supply, occurrence of bus fault or circuit breaker failure does not cause the line outage;

B、Flexible operation. Normal operation two group bus and all circuit breakers are put to

work, to form a multi loop power supply mode;

C 、 The operation is convenient, especially for the bus power operation, do not like

the double bus connection to the load when the inverted operation, so the operation is

relatively simple. But the maintenance circuit breaker or

maintenance or overhaul bus lines, as long as relates to the circuit breaker

maintenance, it is necessary to pay attention secondary circuit

(mainly reclosing protection and the failure to start busbar protection &start other line bus

protection& start remote protection trip ).

2）Disadvantages

The secondary wiring is complexity. Especially the CT configuration more. Fault in the

overlapping area, protection action complexity. Moreover, compared with the double

bus, operation experience is not rich enough.

So far, the biggest shortcoming cause the system connection fix, not splitting operation.

Because of the short circuit current exceed the standard, often need to bus are running.

For double bus connection is easy to realize, and 2/3 connection mode can not be

achieved. With the development of power grid scale more and more big, its malpractice

will be more obvious.

3 / 2 circuit breaker connection method has more advantages than disadvantages.

Aiming at the disadvantages of this connection mode, can work in protective relay

selection, based on the selectivity, rapidity, sensitivity, reliability, protective actions to

improve the precision, simplifies the range configuration, to achieve a single protection,

avoid repetition.

1.3.2 Operation sequence

In power system operation, due to the sequential operation knife caused negatively Hara

closing accidents is one of the common malignant disoperation accident. They must be in

accordance with the provisions of the regulations and administrative unit, to ensure that


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the switching operation is correct. Even the accident occurred in the effects of the

accident, also want to limit in the range.

1、Pull load switch damage and anti misoperation measures

Isolator function is the maintenance device which has enough safety distance was

visible, insulating gap is reliable; insure the safety of personnel and equipment, so it does

not have the capacity of load current and short circuit current. In the presence of pulling

load switch, arc forming conductive channel caused by the phase to phase short circuit,

directly endanger the operation life and cause damage to the equipment, a serious threat

to the safe operation of power grid. To avoid this type of accident, working regulation of

power safety in operation is in details as following, accept commands, fill in the operation

(PTW), operation simulation, operation monitoring and so on . In order to prevent

misoperation, high voltage electrical equipment fitted with anti lock device misoperation

(a few special cases approved by the competent department at a higher level, can be

provided with a mechanical lock). The unlocking tool locking device (including key)

should be kept properly, according to the provisions of the use, forbid illegal unlocking.

Mechanical lock is a key to open a lock, the key to the number and safekeeping, easy to

use. The implementation of these measures reduce the accident happens.

2、3/2 CB switching operation

The nineteenth rules of power safe operation stipulated: power off operation sequence

must be in accordance with the circuit breaker (switch) - load isolating switch (Dao Zha) -

- busbar side isolation switch (switch) the sequence of operation, power on operation

should be performed with the reverse order. Based on such a principle, significance in

the 3 / 2 circuit breaker connection does not.

According to the 3 / 2 connection features, it is easy to understand to the line or

transformer is more important than the bus, so, it is necessary to know if the circuit

breaker of both sides of the isolation switch with load pulls gate accident on different

degrees of impact, to determine the switching sequence.

1 ） The bus side circuit breaker (such as circuit breaker 411 or 421 circuit breaker switching operation order)

A、The line or the main transformer power outage process operation. Such as switching off isolator with load, the accident occurred in the line or main transformer ,then tripping

CB on both sides , cut the fault point, ensure the other line, transformer and bus running;

such as the occurrence of load switching off the accident occurred in the side of a bus

trip, all circuit breakers on the bus, causing no voltage bus, threatening the safe

operation of the system. It should be in accordance with the circuit breaker (switch) - line

or transformer isolating switch (switch) - side bus isolation switch (switch) sequence of

operation. Transmission operation should be performed with the reverse order


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B、The line or the main transformer in service, busbar be power off. if pulling the load switch accident occurred in the side of a busbar,trip all circuit breakers on the bus, cut

the fault point, to ensure line and main transformer normal operation; if pulling the load

switch accident occurred in the line or the main transformer, trip CB on both sides of the

line or the main transformer, causing blackouts, endanger the safe operation of electric

network. It should be in accordance with the circuit breaker - busbar side isolator - - line

or transformer isolator sequence of operation. Transmission operation should be

performed with the reverse order.

C、The line or the main transformer in service, busbar side circuit breaker be repaired. If pulling the load switch accident occurred in the line or the main transformer, trips the

circuit breaker on both sides of the circuit or the main transformer, causing power

outages, and affects the safe operation of the system. if pulling the load switch accident

occurred in the side of a busbar, trip all circuit breakers on the bus, cut the fault point,

does not affect the normal operation of line and transformer. It should be in accordance

with the circuit breaker (switch) - - busbar isolator - - line or transformer isolator sequence

of operation. Transmission operation should be performed with the reverse order.

D 、 The line or transformer power outage, the circuit breaker closing loop operates. If closing load switch accident occurred in the short lead side, trip the circuit breaker both

sides, does not affect the safe operation of the system. If happening with closing load

switch occurred in the bus side, causing no voltage bus, this time turning into a single

bus bar operation mode, reducing the operational reliability. It should be in accordance

with the side of a busbar isolator, short lead side isolator - - CB sequence of operation.

The operation should be performed with the reverse order.

2）The intermediate circuit breaker switching operation sequence

A、The line or the main transformer in service on one side of intermediate circuit breaker, the line or the main transformer on the other sides of intermediate circuit breaker to

power off. Such as load switching off accident running in the line or main transformer

side, resulting in tripping CB on both sides of the line or the main transformer . Such as

load switching off the accident occurred in plan power outage area, Circuit breaker cut

fault on both sides of the line, does not affect the safe operation of power grid. It should

be in accordance with the circuit breaker , power cut side isolator - run side isolator the

sequence of operation, power outage operation should be performed with the reverse

order.

B 、 The line or main transformer in service on both sides of the intermediate circuit breaker , intermediate circuit breaker to maintenance operation. The operation sequence

be considered circuit load switching off accidents on both sides of CB, which impact on

the grid level. In accordance with the circuit breaker, the isolator that has an small impact


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on the grid, the isolator that has big impact on the grid sequence of operation.

Transmission operation should be performed with the reverse order

1.3.3 500KV line operation

1、When shutdown, first open the intermediate circuit breaker, and then open the busbar side circuit breaker, then disconnect the outage line side 11DS (21DS or 31DS) switch,

and then close the busbar side circuit breaker, finally close the intermediate circuit

breaker. when energizing, operating sequence in reverse order.

2、 Switching on or off reactor operation will be performed before getting a shift chief-operator command.

1.3.4 Two systems will be in parallel by synchronization device, two systems require

following conditions.

1、Phase sequence is same

2、Frequency is same, if not , the frequency difference is less than 0.5Hz

3、Voltage angle is same or similar , the voltage angle difference is not more than 20

degree, the voltage value difference is not more than 10％.

1.3.5 Closing loop operation will require below items by synchronization device.

1、two side voltage phase sequence is same

2、Two side voltage value allowances is not more than 10％ normally, not more than

20％

3、Two side voltage angle difference is not more than 20 degree.

4、After synchronization, check load indicator.

1.4 reactive voltage regulation

1.4.1 The 500kV operating voltage should be controlled according to the voltage curves.

Staff on duty should be monitored to ensure that the 500kV voltage, operating in an

acceptable range. Found that the voltage exceeds qualified range should report timely,

adjust value length.

1.4.2 The system needs to adjust the 500kV main transformer tap position before

receiving chief-operator command; according to the voltage curve , operator find voltage

abnormal conditions, then report to chief-operator about voltage and main transformer

tap position ,getting an order, then to go on operating , after be done , report to chief-

operator .


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1.4.3 If the chief-operator get an order from dispatch about reactor, the chief-operator

inform operator operating reactor; normally according to the voltage curve , operator find

voltage abnormal conditions, then report to chief-operator about voltage and main

transformer tap position ,getting an order, then to go on operating , after be done , report

to chief-operator .

2. 500KVtransformer

2.1 500KV transformer summarizing

2.1.1 The 500kV power distribution station transformer is a three-phase integral, neutral

point earth directly, OLTC installed on the high voltage side, connection mode is YN D11,

the forced oil circulation air cooling mode (ONAN 66%, ONAF85%, OFAF100%) .

2.1.2 Transformer working is under rated conditions, meanwhile, operated according to

the stabilization limit issued by dispatcher.

2.1.3 Running voltage of transformer is not more than corresponding tap- changer rated

voltage 105％

2.1.4 The top oil and the coil oil of transformer must be monitored during 500KV

transformer working, the cooling function is the forced oil circulation cooling transformer.

the top oil should not exceed 85℃

2.1.5The transformer is in the normal load or the accident overload operation, operation

time shall not exceed the transformer manufacturers relevant provisions.

2.1.6 When the transformer has high severity defect(such as cooling system is not

normal, serious oil leakage, local overheating phenomenon, dissolved gas analysis

results abnormal) or insulation weakness, transformer should not have overload

operation.

2.2 Inspection of 500kV transformer

2.2.1 Transformer normal inspection

Transformer body &bushing

1）The oil and the coil temperature of the transformer is normal, indicating the correct thermometer.

2）Oil level in transformer oil conservator should be normal, accord with oil level and oil temperature curve.

3 ） The oil level and oil of bushing should be normal, bushing no external damaged crack, no serious pollution, no traces of discharge and other abnormalities


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4）Transformer sound evenly, no sound

5 ） The positions of the transformer oil conservator, sleeve and flange, valve, oil pipe, gas relay, no oil leakage

6 ） Transformer connecting lead is normal, each connection point no overheat phenomenon

7）Gas relay is filled with oil, no gas

8）Pressure release device intact, no oil injection marks and action indication.

9）Respirator intact, oil cup oil, color normal, smooth breathing (bubble turning oil). Silica gel on a single color, wet silica gel is less than 2/3 (standard in grid). For a variety of

color with silica gel, silica gel is not more than 3/4.

10) The control box and a terminal box shall seal well, no water or moisture, temperature

dehumidifier automatic long-term run.

2、cooling system

1）The cooler control box power switch, the switch should be in the correct position, the signal is displayed correctly, without overheating.

2）Put some cooler group into running properly, and adapt to the load and temperature.

3 ） Fan and pump in normal operation, no abnormal sound, oil flow meter indicating normal.

4）No oil leakage at the cooler body 、 a butterfly valve、 pipe joints and other parts

3、On-load tap changer

1）The control switch in the control box is in correct position, tap position display is the same as indication of machinery, no abnormal signal.

2 ） The mechanism box sealing is good, the motor power supply switch should be closed.

3）OLTC oil level is normal, adapt to oil level and oil temperature curve

4）No oil leakage at load switch tank 、 the flange、valve and pipe,

5）Online oil filtering device combination filter pressure gauge indicates the correct, no

oil leakage at flange、valve cover 、cover joint point, work mode switch position is correct.

2.2.2 Special inspections

1、Transformer be special inspected in the following cases.

1）The new or overhaul 、renovation transformer will be put into 72 hours


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2）Transformer protection act and trip

3）Transformer has serious defects

4）Abrupt climate change (such as when the wind, fog, snow, hail, cold, etc.)

5）The thunderstorm season, especially after the thunderstorm

6）High temperature season, the peak load period

7）Transformer overload or excessive voltage operation

2、Transformer special inspection items

1）Porcelain should no discharge phenomenon after light went out, connection point has no overheat

2 ） During high wind, there are no debris and lead swing on transformer body and surrounding,.

3）After the thunderstorm ,check porcelain no traces of discharge, the action of arrester

4）During fog, check porcelain on flashover phenomenon.

5）On heavy snow day, check connection point no melt

6）When temperature change, check oil level and lead sag.

Mutation temperature should sag condition check oil level and lead

7 ） Transformer overload or excessive voltage operation, at least inspected once per hour, with particular attention to the connection point temperature and overheating, and

has no sound and oil level etc.

2.3 500KV transformer acceptance check before put into operation

2.3.1 Transformer acceptance check

1、Qualified installation and test, transformer can be put into operation

2、No sundries inside transformer, wire joint should be fastened.

3、On load voltage regulating switch should be operated in a cycle before operation, check the normal action. Each phase switch position is in conformity with the

requirements, tap display consistent with the machinery indication

4 、 Cooling device main and backup power supply change over test correctly, cooler running well , oil flow indication correctly.

5、Neutral point , shell, core connect to earth and reliable

6、valves of each part of transformer is in correct position.


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7、Oil level of the transformer body, OLTC, bushing indicating normal.

8、The valve between gas relay and oil conservator is in open position, gas relay filled with oil, secondary wire no corrosion.

9、Silicone no damp in respirator, oil amount in oil cup is proper, oil color is normal.

10、Transformer temperature indicating is correct on the local and remote.

11 、 The control box and a terminal box is sealed well, no moisture, temperature dehumidifier automatic run.

12、No alarm signal.

13、The new or overhaul、oil filter and renewing the oil of transformer should be put into cooler and remind maintainer release air inside oil before put into service .

2.3.2 Inspections before put into service.

1、Transformer protection should be put into normal, no abnormal action signal

2、Three phase tap position is same, tap display accordance with machinery indicator

3、Cooling system power supply is in service, cooler work function meet the requirement.

4、No external sundries, no left ground lead.

2.4 500kV transformer running and operation

2.4.1 The general operation principle

2.4.1.1 500kV transformer power on or off, it should begin to power on or off from 500KV

side.

2.4.1.2 Check and adjust the charging side bus voltage and transformer tap positions,

ensure that the charging voltage does not exceed the specified value before 500kV

transformer will charged.

2.4.1.3 Transformer coil temperature should be consistent, if the three-phase

temperature had obvious difference, should be timely check and handle.

2.4.1.5 During 500kV transformer normal operation, fire water spray device outlet valve

should be closed, to prevent disoperation; if fire, to open the valve and fight the fire; the

instruction should be placed on the site.

2.4.2 Cooling system

2.4.2.1During the transformer normal operation , cooling system two power supplies

come from IA/IIA PC section and be powered on, one is working ,the other is standby ,

check cooler work normal or not after two power supply changer over.


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2.4.2.2 Forced oil cooling transformer operation not allowed to outage all cooler

2.4.2.3Before forced oil circulation transformer put into operation, first manually open all

the cooler operation for a period of time, exhaust the residual air ;after main transformer

shutdown, should let the cooler to run to main transformer coil temperature below 60 ,℃

then shut off the cooler.

2.4.3 on-load tap changer device

2.4.3.1 The two transformers is in parallel operation, the tap voltage should be almost

consistent, tap position of the same type of transformer must be consistent.

2.4.3.2 On-load tap changer device controlled by the dispatch and make a record.

2.4.3.3 The voltage regulating operation must be done step by step, watch the voltage

and the current normal, tap position and action indicator changing will comply with the

voltage regulating.

2.4.3.4 On-load tap changer of paralleling transformer

1 、 For the design of a combination OLTC operation, when the parallel operation of transformers can be used on combination mode, should choose a "master", the other

"follower".

2 、 When combination mode transformer maintenance, relieve debugging mode, after maintenance, put into service.

3、The transformer is not on debugging mode, voltage mode selection "alone".

4、Transformer regulate the voltage on "alone" mode, two transformer operate in turn, transformer tap position difference should not exceed 1.

2.4.3.5Slide, timeout or mechanism anomaly occur on OLTC operation, press the "stop"

button or pull the motor power supply, stop voltage operation, report shift-operator and

dispatch, check and deal with.

2.4.3.6 Load voltage regulating switch (OLTC) is equipped with online oil filtering device,

used to clean and dry the OLTC oil. The normal operation of the oil filter should be set to

"automatic" mode, namely it start automatically when you start running OLTC. In order to

prevent the transformer OLTC is not used for a long time, it caused impurity at the bottom

of the tank. so quarterly the oil filter should be tested in manual function.

2.4.3.7 In the following cases, OLTC is prohibited:

1、OLTC light gas relay alarm.

2、OLTC oil quality not meet the standards

3、OLTC oil level abnormal


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4 、 Transformer overload, not suitable for voltage operation; overload 1.2 times, no allowed voltage operation.

2.4.3.8 There are two kinds of operation mode on OLTC, one is remote mode(ECS) ,the

other is local mode(mechanism box).

Normally remote operation is selected; select switch in mechanism box is in remote

position. In case of abnormal conditions or maintenance, local operation is selected

2.4.4 Gas relay protection

2.4.4.1 During operation, heavy gas relay act. when the transformer differential protection

is disable ,not permit to change heavy gas protection configure.

2.4.4.2During operation, the follow working must authorized by the dispatch, which heavy

gas protection is put into alarm, after work completed, heavy gas protection is put into

trip.

1、oil filter, refueling or discharge oil on transformer body.

2、Gas relay check and test on transformer body .

3 、 The oil level indication rise on transformer body, if necessary, open ventage or discharge oil valve, check respirator.

4、The replacement of a transformer oil submersible pump

5、replace the transformer oil filter adsorbent .

6 、 Before exchange respirator silicone or check respirator , make sure that respirator work well, otherwise put heave gas protection into alarm.

2.4.4.3 The follow OLTC working will authorize by the dispatch during transformer

running period. After put heave gas protection into alarm, begin to work. when the

working is over, put heave gas protection into trip.

1、The OLTC fueling 、oil drainage

2、Oil filter device maintenance

3、Gas relay check or test

4、The oil level indication rise on OLTC body, if necessary, open ventage or discharge oil valve, check respirator.

5 、 Before exchange respirator silicone or check respirator , make sure that respirator work well, otherwise put heave gas protection into alarm.

2.5 500KV transformer operation considerations


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2.5.1 Main transformer cooler power circuit has three-phase power monitoring function,

make sure that backup power change over automatically when any phase of main power

supply is lost , otherwise make a plan.

2.5.2 Do not allow magnetic objects close to the oil flow meter

2.5.4 Transformer maintenance and CB need loop closing operation; this time

transformer protection is disable, after maintenance, put transformer protection into

service.

2.5.5 Oil immersed natural cooling / air cooled transformer, cooler stop working, the load

and run time should be in accordance with the provisions of the manufacturing plant.

when the cooling system failure, the top oil temperature not higher than 65 , allowing℃

operation with rated load

2.5.6 For forced oil circulated air-cooled transformer, when the cooling system fail ,

remove all cooler , allow to run 20 min with rated load .if the top temperature do not

reach 75 in 20 min, allow up to 75 ,but the time do not exceed 1 hour, if the top oil℃ ℃

reach 75 ,report to shift-operator and dispatch stop running .℃

2.5.7 When the transformer temperature reach the setting, auxiliary cooler do not start

automatically, immediately start by hand.

2.5.8Cooling system control switch trip, try to switch it on , if trip again ,not allowed to

change big switch or short circuit directly.

2.5.9 Transformer fire extinguish apparatus is normally in manual position.

2.6 500kV transformer abnormal and accident treatment

2.6.1 Abnormal and accident treatment general principle

1、One of the following circumstances transformers should immediately be outage

1）Transformer noise big, uneven, crackles.

2）Transformer serious oil leak, oil conservator no oil indication

3）Pressure release device oil injection or smoke

4）The bushing has serious oil leak and discharge phenomena

5 ） In the normal cooling, load, voltage condition, transformer top oil temperature, coil temperature exceeds the limit and to continue to rise

6）Transformer smoke and fire


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2、One of the following transformer circumstances should strengthen the supervision and inspection, determine the cause, and immediately report to the dispatcher and chief-

operator, take corresponding measures

1）transformer has abnormal noise

2） In the load, cooling condition, under normal conditions, the transformer temperature rising

3）Outgoing line joint overheat

4）Transformer oil leakage, oil conservator oil surface indicating decreased slowly.

3、After transformer heave gas relay and differential protection trip together, no allow to power on by force without unidentified reason and treatment.

4、After transformer gas relay or differential protection trip, check no exterior obvious fault and gas analysis is qualified, if necessary, try to power on.

5、After transformer backup protection trip, going on exterior check, only identify the fault and do the effective isolation, try to power on.

6、Transformer trip because for internal fault, stop all cooler as soon as possible , avoid that the free carbon produce metal particles entering normal area.

2.6.2 Diagnosis and treatment of abnormal situation

1、transformer overload

1 ） Make a record that load starting time 、 load value and prevailing circumstances temperature

2）Put cooler into service by hand.

3 ） The overload situation report to dispatcher, take measures to decrease the load. According to the provisions of the transformer load limit value, monitor and control load

amplitude and time of normal overload and accident overload.

4）For load transformer special inspection, check the cooling system and the connection point has no overheat

5）Special person shall be assigned to closely monitor the load and temperature load transformer, if the overload operation time has exceeded the allowed value, operator

should immediately report dispatcher to reduce transformer load to rated load.

2、Transformer overheat

1) Check if the thermometer, transducer failure, report chief-operator and treatment.


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2) Check whether the cooler fault or the cooling efficiency reducing, all cooler should put

into service.

3) Check whether the reason is overload or not, deal with it according to the transformer

provisions.

4) No reason rise, report to dispatcher and shift-operator ,then check and treatment.

3、Oil level high or low

1) The reason of high level

a) Oil level indicator fault

b)；Oil conservator capsule rupture

c) Respirator blocked

d) Temperature rapid rise

2) The reason of low level

a) Oil level indicator fault

b) Oil conservator capsule rupture

c) Transformer oil leakage

3) The oil level is too high or too low, immediately report dispatcher and shift-operator, in

time deal with it to prevent heavy gas protection malfunction

4、Cooler fault

1）A single set of cooler is in trouble in the operation, should immediately start standby cooler and deal with the fault of cooler, report shift-operator, contact the maintenance

treatment

2 ） All Cooler stop, should immediately report the shift-operator and dispatcher, designate a person to monitor, record the load and temperature of the transformer, and

immediately try to restore the cooler operation as soon as possible. The transformer shall

be continuously monitor, operation time and the top oil temperature exceeds the

specified value, should be immediately report dispatcher to stop transformer.

Groups of cooler stop, found that general power switch tripping, try to power on. If you

fail, all cooler is out of service, and then close the general power switch, and then put the

cooler one by one, find the point of failure.

5、Pressure release device action.

1) Check gas inside gas relay and analyze action reason.


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2) Check whether respirator pipe is smooth or not

3) Check whether each accessory oil leakage or not .

4) Check whether body case is normal or not

5) Secondary circuit fault

Report shift-operator and dispatcher, inform maintenance personnel to take the body oil

and gas analysis. When the relief valve is in pressure recovery, reset the button by hand.

6、Gas protection action

1) Light gas action may have the following reasons

a) After respirator and cooler put into service, Oil filter、refuel 、change oil, air entering transformer body.

b) The oil level is lower because of oil temperature drop and oil leakage.

c) Light fault inside transformer.

d) Secondary circuit or gas relay fault.

e) Negative pressure air entering the transformer body is caused by oil pump inlet pipe

joints leak

2) After light gas act, not allow to put heavy gas into alarm, immediately check gas relay

and take gas for chromatographic analysis, find out the reason and eliminate at once.

3) Light gas alarm or heavy gas trip because of gas occurring inside gas relay,

immediately take gas for analysis. Otherwise, gas colors disappear .

Gas identification table

Number gas property burning test fault nature

a colorless, tasteless no combustible air

b yellow nonflammable woodiness fault

c light grey combustible paper fault

d grey or black inflammable oil or core fault

7、Differential protection action

1) The reasons of differential protection tripping


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a 、Transformer internal fault

b、Transformer CT body malfunction

c、Differential protection secondary circuit fault or maloperation.

2) Differential protection action and treatment

a、Each side of the transformer differential CT has no flashover or breakdown traces, transformer bushing is good

b、Transformer oil level、oil temperature is normal.

c、 Check whether gas protection and pressure release valve act or not ,check whether gas relay is full of oil or not;

d 、Check whether the differential relay and secondary circuit is normal or not .

e、Check whether all line protection act or not

f 、The differential protection trip, immediately report shift-operator and dispatcher, then find out the reasons , go on transformer body test without secondary circuit fault, after

the test result is normal , transformer is put into service again.

8、Transformer backup protection action

1) Check whether line backup protection within the protection scope is act or not;

2) Equipment porcelain part within the protection scope has no flashover and damage

3) Check whether protection device is normal or not .

If transformer differential、gas protection no action , check and deal with fault point, if grid is requested, try to power on transformer again without going on transformer test.

9、 Transformer fire

If transformer fire, immediately open CB of transformer every side and cooler AC power

supply, start water spray, report chief-operator, take measures to put out a fire. If fire is

on the top of transformer, open the valve at the bottom of transformer; if fire happen

inside internal transformer, not allows discharging oil in order to avoid transformer

serious explosion.

Attach : Oil immersed forced oil circulate cooling transformer accident overload

permission running time (h: min)

Overload multiple Environment temperature ( )℃

0 10 20 30 40


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1.1 24:00 24:00 24:00 14:30 5:10

1.2 24:00 21:00 8:00 3:30 1:35

1.3 11:00 5:10 2:45 1:30 0:45

1.4 3:40 2:10 1:20 0:45 0:15

1.5 1:50 1:10 0:40 0:16 0:0.07

1.6 1:00 0:35 0:16 0:08 0:05

1.7 0:30 0:15 0:09 0:05 +

3. High SF6 CB

3.1 Inspection of CB

3.1.1 Circuit breaker routine inspection items

1 、 Wire connection part has on overheating, moderate curvature, no broken wire and regular infrared temperature measurement.

2、Insulated porcelain sleeve surface clean, no damage or discharge, no abnormal sound

3、Circuit breaker actual switching position consistent with mechanical, electrical position indication.

4、SF6 CB pressure is normal.

5、Operating mechanism pressure is normal, spring circuit is normal.

6、The select switch in the mechanism box and control cabinet should be in the "remote" position, the power switch is in the on position

7、Thermostatic dehumidifying device is on automatic position.

8、The seal is intact on control box, electrical components should be clean and intact, and the box door closes tightly, no dampness.


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3.1.2 The special inspection of circuit breaker:

1、CB trip.

2、New installment or maintenance .

3、high temperature season、severe weather，peak load .

4、CB operating mechanism frequent energy storage.

5、The circuit breaker has serious defect

3.2 The circuit breaker acceptance after the overhaul

1、Test items all in readiness, test data meet the requirements

2、Cleaning equipment, no temporary short-circuit wiring and other remnant.

3、Porcelain clean, no damage crack, circuit breaker and its operating mechanism, the lead firm fixation, metal parts without corrosion or mechanical damage, shell grounding

wire welding firm.

4、Phase color signs are right.

5、The mechanism box sealing is good, the secondary terminal arranged in neat rows, joint shall be fastened, no loosening. The secondary terminal block and the auxiliary

switch insulation clean and firm, the auxiliary switch should be in the corresponding

position.

6、SF6 CB pressure is normal.

7、Energy storage mechanism normal work

8、Circuit breaker position and alarm signal should be the correct action.

9、Anti disoperation device is complete, good.

10、Closing or opening operation act right on remote or local place.

11、Circuit breaker in local control cabinet wire fastening, no looseness, the temperature in the cabinet control device work properly.

12、Three-phase inconsistent protection act correctly, time setting requirements

3.3 Operation and control of circuit breaker

3.3.1 The circuit breaker is provided with remote control and local control function.

Normally use the "remote control" mode of operation, only if CB cannot be live, CB

should "in local control" operation. The local control circuit is latched with S104 and

isolator normally closed contact.


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3.3.2 Check the circuit breaker control circuit and the operation mechanism, namely CB

is with operation conditions. Before CB is Switched on, check relay protection in service

in accordance with the provisions.

3.3.3 Monitor the voltage, current, power meter indication and circuit breaker state during

the CB running period.

3.3.4 After operate CB, check CB status indication 、the meter indication and three-phase mechanical indicating correct.

3.3.5 Circuit breaker is powered on, as a result of relay action, immediately stop the

operation, report to shift-operator, strictly prohibited to power on again without checking.

3.3.6Circuit breaker trip, immediately go on external check, and make the circuit breaker

trip record. When CB fault trip times has reached allowance number, report to shift-

operator, required to stop the reclosing protection.

3.4 CB operation consideration items

3.4.1CB control function switch to remote position in local LPCC cubicle, S104 switch to

maintenance position, after this, CB is controlled on control room.

3.4.2 If CB control function switch to local position, cut off protection and tripping or

closing circuit of automatic device, local position alarm signal and control loop break

signal is coming.

3.5 CB abnormal treatment

3.5.1The following cases happens on CB, immediately report to shift-operator , stop CB

operation

1、Porcelain sleeve has serious breakage and discharge phenomena

2、Gas in SF6 CB serious leakage, lower than closure pressure

3 、 The pressure in CB operating mechanism is reduced, locking closing and opening operation.

4、Circuit breaker internal crackles or oil smoke

5、Circuit breaker lead severe overheat

6、Other serious defects

3.5.2 Circuit breaker SF6 low pressure alarm come, the circuit breaker can still run,

immediately report to shift-operator, arrange to supplement SF6 gas . When SF6 low

pressure blocking signal come, locking circuit breaker operation, immediately report to

shift-operator for circuit breaker outage treatment, treatment principles. See items at

3.5.4


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3.5.3 When closing locking happen in CB, go to site and check, immediately report to

shift-operator. If the circuit breaker is in the off position, the circuit breaker switches to

maintenance position. If the circuit breaker is in the closing position, the circuit breaker is

isolated and send a person to deal with . Circuit breaker has closing locking because of

closing spring energy storage failing , so check storage motor and energy storage spring

travel switch , try to restore. As a result of motor damage or AC power lost , CB can not

be electric energy storage, if necessary, energy storage by hand.

3.5.4 When opening locking happen in CB, go to site and check, report to shift-operator.

If the circuit breaker is in the off position, the circuit breaker switches to maintenance

position. If the circuit breaker is in the closing position, open the isolator on both side of

CB, otherwise, cut all power supply related to CB, isolator operation should be in remote

control mode.

3.5.5Three phase inconsistent happen in 500KV CB, inconsistent protection act ,if the

action result is mistaken, try to restore three phase operation , if fail , immediately open

CB, report shift-operator.

3.5.6 when three phase inconsistent and closing &opening locking happen , immediately

report shift-operator to change operation mode, treatment principle refer to 3.5.3 and

3.5.4.

3.5.7Three phase inconsistent phenomenon

1、When CB closing operation , only two phase closed , immediately close CB again , still two phase closed , open CB at once, report shift-operator , if CB closing operation , only

one phase is closed, immediately open CB, report shift-operator to stop operation.

2、When CB opening operation, only two phase opened , not allow to close , immediately open CB again, if failed ,report shift-operator to arrange person to deal with it , if CB

opening operation , only one phase opened ,try to restore three phase operation , after

that ,report shift-operator.

3.5.8CB inspections with refusing to close

1、Check whether remote conditions are required or not

2、Check whether SYN switch and SYN conditions is required or not .

3、Check protection action signal and reset the relay.

4、Check whether mechanism SF6 pressure is normal or not.

5、Check whether the operating power is good or not.

6、Check whether the control circuit and closing coil is normal or not.

After check, above items is normal, try to close again, if fail, report shift-operator.


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3.5.9 CB inspections with refusing to open.

1、Check whether remote conditions are required or not

2、Check whether mechanism SF6 pressure is normal or not.

3、Check whether the operating power is good or not.

4、Check whether the control circuit and opening coil is normal or not.

After check, above items is normal, try to close again, if fail, report shift-operator.

3.5.10 “CB energy storage fail signal or heater power supply fail signal come , go to site

and check the reasons to deal with it ,after that , try to power on again, if fail , report shift-

operator ,

3.5.12 When CB occur in explosion or gas serious leakage, approach CB from safety

side, if necessary, wear protecting poison mask and safety clothing .

Circuit breaker parameter

Items GL317XD

Standard IEC

Ur Rated voltage (average) KV 500

Ir Rated current A 4000

Fr Rated frequent HZ 50

Ip Withstand current (peak) KA 173

Ik Withstand current (average) KA 63

U

d

Rated insulation level

(above sea level)

Rated short time power frquence

withstand voltage(average)

Phase to earth ,phase to phase KV 860


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U

p

Gap KV 900

Rated The lightning impulse withstand

voltage (peak)

Phase to earth ,phase to phase KV 1800

Gap KV 1675

Is

c

Rated short-circuit breaking current KA 63

Rated closing, opening current KA 173

Full break time ms 50±2

Rated operating procedure CO-15s-CO,O-0.3s-CO-3min-

CO

Main circuit resistant (new contact) µ Without high voltage connection

in arc cubicle

SF6 GAS

GL317XD

Allowance min temperature -30℃

(-22F)

-25℃

(-13F)

20 (68F)absolute pressure℃

Pre (insulated absolute pressure)

0.75MPa

(108.8p.s.i)

0.85MPa

(123.2p.s.i)

20 (68F),101.3KPa relative℃

pressure

Pre insulated relative pressure0.65MPa

(94.3p.s.i)

0.75MPa

(108.8p.s.i)


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Pre insulated alarm relative

pressure

Pre insulated min relative

pressure

0.54MPa(Pme+0.03MPa)

(78.3p.s.i)

0.64MPa(Pme+0.02MPa)

(92.8p.s.i)

0.51MPa

(74p.s.i)

0.61MPa

(88.5p.s.i)

Three CB weight 97.5KG 111.6kg

SF6 GAS density

Pre

Pae

Pma

49.59kg/m3

41.66kg/m3

39.55 kg/m3

57.04 kg/m3

48.8 kg/m3

46.6 kg/m3

4. Voltage and current transformer

4.1 Summarizing

4.1.1 Current transformer external insulation material is made of porcelain. The inner

insulating medium is oil, so adopt the kind of type CT.

4.1.2 Current transformer installation is similar to circuit breaker installment.

4.1.3 Voltage transformer has PT and CVT type.

4.1.4 in our substation , three CVT is used in line/ main transformer , single CVT is used

in BUSBAR.

4.2 inspection of voltage and current transformer

4.2.1 Routine inspection

1、wire connection part without overheating, lead radian moderate, regularly check on pile head by infrared thermometer.

2、Internal part abnormal

3、The terminal box door seal intact closed tight, no dampness inside the box.

4、oil immersed porcelain mode current transformer

a、Porcelain sleeve should be clean, no damage, crack and discharge

b、Oil level and oil color normal, no oil leakage


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5、Electromagnetic type voltage transformer(PT).

a、Porcelain sleeve should be clean, no damage, crack and discharge

b、Oil level and oil color normal, no oil leakage

4.2.2 Special inspection

a、After tripping

b、After new operation、maintenance test.

c、High temperature season, the severe weather, the peak load

d、Existing defects.

4.3 The acceptance items after transformer repair

4.3.1Test items, test data meet the requirements

4.3.2 Cleaning equipment, no temporary short-circuit wiring and other legacy

4.3.3 Porcelain clean, no damage crack, wire fixation, metal parts without corrosion or

mechanical damage, shell grounding wire welding firm

4.3.4 Phase color symbol obvious 、right.

4.3.5 Terminal box sealing is good, the secondary terminal arranged in neat rows, joint

shall be fastened, no loosening, no clear

4.3.6 Oil level is normal, no leakage, oil level gauge glass should be complete and clean

4.4 The current and voltage transformer operation

4.4.1 The current transformer operation

1、Secondary circuits no open

2 、 The secondary circuit operation sequence “close first , then open (link ) ”, disable corresponding protection before operation.

a、Put into operation: first put the connection piece, after remove the short piece

b、Out of operation: first put a short piece, after removing the connecting piece

c 、 The changing busbar operation mode in fixed connecting busbar protection configure: first put the connection piece, then removing the original connection piece.

3、On circuit breaker opening position, the secondary circuit operation sequence “close first , then open (link ) ”,

a、Put into operation: first put the connection piece, after remove the short piece


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b、Out of operation: first put a short piece, after removing the connecting piece

c 、 The changing busbar operation mode in fixed connecting busbar protection configure: first put the connection piece, then removing the original connection piece.

4.4.2 The voltage transformer operation

1、Secondary circuit no short-circuit

2、he operation sequence “ when put into service ,first operate on high voltage side, then operate on low voltage side ; When out of service, operate in reverse order.

3、When one of double busbar stop running , secondary circuit should be open.

4.5 The current and voltage transformer operation consideration matters

4.5.1 After new CT operation or CT secondary wire changed, phase check should be

done.

4.5.2。After new PT operation or PT secondary wire changed, taking load should be done

4.5.3 When people work at CT circuit on 3/2 CB connection protection configure, remind

staff to take safety measures for avoiding disoperation.

4.5.4 When the CVT is connected with the carrier equipment, second grade grounding

switch should be in open position, if required to work ,close grounding switch before the

dispatch permits. disable related high frequency protection before closing. If the CVT is

not connected with carrier equipment CVT, secondary grounding switch should be

closed.

4.6 The current and voltage abnormal treatment

4.6.1 The follows cases happen ,report the dispatcher ,quit CT and PT out of service .

1、Lead connection parts serious overheat.

2、Inside abnormal noise.

3、PT high voltage fuse continuous break

4、Smoke or peculiar smell.

4.6.2 Silicon rubber insulation SF6 CT

1、Silicone rubber surface has serious cracks, discharge ablation;

2、SF6 gas leakage .

4.6.3Porcelain oil immersed type CT

the porcelain sleeve has serious breakage and discharge phenomena；


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Serious oil leakage , no oil indicator

4.6.4 Electromagnetic type PT

1、the porcelain sleeve has serious breakage and discharge phenomena；

2、Serious oil leakage , no oil indicator.

3、Secondary voltage abnormal

4.6.5Capacitance type transformer (CVT)

1、the porcelain sleeve has serious breakage and discharge phenomena；

2、Slight leakage of oil

3、Secondary voltage abnormal

4.6.6CT secondary open circuit judgment

1、Current no display, power meter display diminishing.

2、CT break signal send out.

3、CT interior abnormal noise.

After CT secondary circuit is open, check whether measurement circuit or protection

circuit is open, and immediately report to the dispatcher and shift-operator, transfer load

or power off. In case of emergency, stop the circuit breaker, then report to shift leader.

4.6.7 The voltage transformer abnormalities may develop into failure, treatment principles

are as follows

1、Not allow to open primary switch in local place.

2、Not allow to secondary paralleling.

3、Not allow to busbar protection out of service.

4、Primary switch will open by remote operation , if not isolation by primary switch , CB should be cut ,then isolate the voltage transformer.

4.6.8 Secondary voltage disappear treatment

Voltage transformer Secondary switch tripped , check and find no fault point ,allowed to

try one time, if the secondary switch again tripped , not allowed to do it, report shift-

operator, disable the relevant protection and deal with it .

5. High voltage isolator

5.1 Summarizing


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5.1.1High voltage isolator (hereinafter referred to as the "switch") should not cut the load

current and fault current, but the practical operation allows for cutting small current loop.

5.1.2 the follow operations will be permitted.

1、When power system is not connected to ground, open or close the voltage transformer .

2、Open or close arrester without thunderstruck

3、Without approval, in test case, not pulling bus charging current with 500kV knife

4、Open or close circuit breaker or isolator bypass current.

5、Open or close 3/2 connection busbar loop current.

6、Open or close the neutral switch of transformer without system grounding fault.

7、Open or close on load auxiliary transformer without system grounding fault 。

8、Open or close low reactor without system grounding fault.

Note: 1, the above equipment is long-term disabled, not allow opening or closing switch

without the test.

2, If the equipment is abnormal or fault, not allow to operate in local place. .

5.2 Isolator inspection

5.2.1 Isolator routine inspection

1、Porcelain clean, no damage, crack, no traces of discharge.

2、Closing or open status is in place,close contact is good, no overheat

3、Equalizing voltage ring shall be level and firm, the arm is without deformation, offset.

4、Lead wire should be no loose, the severe wobble, burn off phenomenon, wire clamp no cracking phenomenon.

5、The positioning screw not falls off.

6 、 mechanical position indicating correct, three-phase consistent; control panel, monitoring screen, the protection screen consistent with the actual location.

7、The operating mechanism box, terminal box shall be sealed well, no humidity.

8 、 The select switch in mechanism box should be in the "remote" position; the motor power supply switch should be closed

9、Temperature dehumidifier device in mechanism box and terminal box should be in the automatic position.


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10、Check temperature regularly by infrared thermometer

5.3 The isolator acceptance after repair

5.3.1 Test items, test data meet the requirements

5.3.2 Anti misoperation device is complete, good.

5.3.3 Appearance inspection.

a、Cleaning equipment, no temporary short-circuit wiring and other legacy.

b、Porcelain clean, no damage crack, metal parts no corrosion or mechanical damage.

c、Isolator and its operating mechanism, the lead firm, pile head clamp is with drainage hole.

d、Phase color symbol is obvious and right.

e、mechanism box, terminal box sealing is good, the secondary terminal arranged in neat rows, joint shall be fastened, no loosening, no clear.

5.3.4 Operation test and check

1、 The isolator is operated well in the remote control and manual operation. Operation mechanism should be flexible, smooth, no jamming and other abnormal situations. three-

phase synchronization requirement is up to standard.

2、 The auxiliary contact switchover correctly, closing and opening position indicator is consistent with the actual indicator.

3、Isolator with arcing contacts is operated from open to close, arc contacts should first touch, then main contacts touch; from close to open, contacts touch sequence is on the

contrary.

4、When closing, dynamic and static contact touch closely , the contact surface should be clean, smooth

5.4 Isolator operation

5.4.1 Operation sequence of isolator

When power cut, open the CB first, and then open not power side isolator, open power

side isolator at last; when power on, the operation sequence is on the contrary.

5.4.2 During isolator operation, check the circuit breaker is in the off position, not allow to

close or open the isolator with on load.

5.4.3 Before isolator is closed, check the grounding switch open, disconnect all the

ground wire, and prohibit closing the grounding switch with ground wire.


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5.4.4 before closing grounding switch, check the corresponding switch open, and then

close it after confirming no power.

5.4.5 After switch is operated , check auxiliary contact switchover right , busbar

protection 、line protection 、monitor system indicator is correct.

5.5 Isolator operation consideration matters

5.5.1The control power of isolator is in service for long-term; if the mechanism box、the operation box and the terminal box have bad sealing, water enter into box, the power

supply should be cut , if necessary , put the power supply temporarily.

5.5.2 For the horn shaped static contact switch, closing or opening operation in winter

must check the horn mouth without frozen or snow, only allowed the closing operation,

prevent support porcelain crooked or down, cause accidents.

5.5.3 When the switch with on load should be opened quickly, do not allow the midway to

close. When the switch with on load should quickly close, do not allow the midway to

open.

5.5.4Switch electric operation failure, it is strictly prohibited to unlock, you must identify

the cause, confirm the correct operation, and get shift-operator approval to unlock

operation.

5.6 Isolator abnormal treatment

5.6.1 The following cases happen in isolator, report shift-operator, outage and deal with

it.

1、The support or rotating porcelain damage or discharge

2、Dynamic and static contact or connection part overheat or damage

3、Isolator in the operation process, not pull to open or close is not in place;

4、Operation connecting rod fracture, support porcelain fracture

5.6.2 Switch electric operating failure, first check the device name number, check the

corresponding circuit breaker and switch state, to determine whether the switch operation

conditions are satisfied, it is strictly prohibited to operation without lock. In confirmation

of correct operation, check the operation power and motor power supply is normal, check

whether the motor thermal relay and power open phase protection relay action or not,

then try to recover, if the fault can not be eliminated or not abnormal, immediately

reported shift-operator , inform maintenance for processing. if necessary, apply for

unlocking operations, including manual operation.


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5.6.3 During the operation, find the switch contact is bad, pile head cracking phenomena,

immediately measure by infrared temperature, and report shift-operator to reduce load or

outage, strengthen surveillance before outage.

5.6.4 If the electric operation process stop because of a power outage or failure and the

switch arc occur, in order to avoid contact continuous arc and switch auxiliary contacts

indeterminacy state affected the protection, the operator should try to immediately close

or open the switch by manual, after this, report shift-operator, check and deal with it.

6. 500KV reactor

Line reactor parameter

Rate capacity 111.3/3MVA Rate voltage 550/3kV

Rate current 116.8A Resistance 2718.7Ω/phase

Phase num Single Cooling function ONAN

Temperature rise Oil 50℃ Manufactured by Hitachi,Ltd. Tokyo

JapanCoil 55℃

6.1 Summarizing

6.1.1Reactor is the large capacity inductance coil and connected in the 500kV line , it is

the role of compensating high voltage transmission line capacitance and absorb the

reactive power, prevent voltage rise due to power grid light load.

6.1.2 Three single-phase reactor is compound of three reactor, connection mode is for

star, and the neutral point grounding is via small resistor.

6.2 High voltage reactor

6.2.1 Reactor routine inspection

1、The oil temperature and the temperature of the coil is normal, indicating the correct thermometer.

. 2、The oil level of oil conservator in three high voltage reactor and neutral point reactor is normal, accord with the oil level and oil temperature curve .

3 、 The oil level, oil color should be normal, external bushing no damaged crack, no serious pollution, no traces of discharge and other abnormalities.


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4、The three-phase high voltage reactor and neutral point reactor inner voice even, no sound.

5、Oil conservator, sleeve and flange, valve, oil pipe, gas relay, no oil leakage

6 、 The connecting wire is without exception, each connection point no overheating phenomenon.

7、Gas relay is filled with oil, no gas

8、Pressure release device intact, no injection marks and action indication.

9、Respirator intact, oil cup oil and oil color is normal, breathing is smooth (bubble turning oil). For single color Silica gel, wet silica gel is less than 2/3 . For a variety of color silica

gel, wet silica gel is not more than 3/4.

Reactor current basic balance

the control box and a terminal box shall seal intact, no water moisture, temperature

dehumidifier is on automatic mode for long-term time.

6.2.2Reactor special inspection is as following.

1、The new operation or after overhaul.;

2、Reactor protection trip or alarm.

3、Line protection trip or alarm.

4、Reactor has serious defects

5、High temperature season, climate changes (such as wind, fog, snow, hail, cold, etc.)

6、The thunderstorm season, especially after the thunderstorm;

7、Reactor over voltage operation.

6.3 High reactor operation

6.3.1 Continuous operation under reactor 105% rated voltage.

6.3.2 The temperature rise is as follows under reactor 105% rated voltage.

coil average temperature rise 60℃

top oil temperature rise 55℃

coil max temperature 73℃

oil tank max temperature 73℃


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In order to prevent reactor insulation and oil degradation rate, top oil temperature is often

more than 85 .℃

6.3.3 Reactor is not allowed without arrester.

6.3.4 The following works of reactor should first obtain shift-operator agreement; the

heavy gas protection is put into alarm, and then begins to work, after the end of the work,

heavy gas protection is switching to tripping.

a、Oil filter、refuel and oil discharge .

b、Gas relay check and test.

c、he oil level gauge of oil surface is abnormal rise, in order to ascertain the reason ,it is necessary to open the gas or oil discharge valve, check the respirator work

d、Make sure respirator is smooth before exchange respirator or disconnect respirator, otherwise put gas protection in signal position.

5、Replace reactor sorbent.

6.3.5 Reactor has three states ,such as operation 、cold standby 、maintenance .various state defined in the follow table.

state condition of satisfaction

running reactor switch is closing

cold standby reactor switch is opening

maintenance reactor switch is opening , reactor grounding switch is closing.

6.4 Reactor operation consideration matters

1、Closing or opening reactor shall be carried out on the line ground conditions, if line not grounding, make sure the line no voltage and cold standby for 15 min to close or open

switch.

2、 High voltage reactor or the point reactor maintenance, and circuit breaker need to run again, disable its protection tripping outlet, after maintenance, it recover.

6.5 High voltage reactor abnormal and accident treatment.

6.5.1The follow cases happen in reactor, report shift-operator to outage.

a、The three-phase reactor body and a neutral point reactor sound abnormal, uneven, crackles;


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b、The three-phase reactor body and a neutral point reactor have serious oil leakage, oil conservator on oil indication

c、Pressure release device injection or smoke;

d、The bushing has serious broken oil and discharge phenomena;

e、In the normal cooling、voltage and temperature, coil temperature exceeds the limit and continue to rise;

f、。Smoke and fire

6.5.2 Reactor oil level too high or too low

1、Oil level too high reasons

a、 Oil level indicator fault.

b、Oil conservator capsule fracture.

c、Respirator block

d、Reactor temperature rise

2、Oil level too low reasons

a、 Oil level indicator fault.

b、Oil conservator capsule fracture.

c、Reactor oil leakage.

The oil level is too high or too low, immediately report to shift-operator, the timely

processing. During processing operation, prevent heavy gas protection malfunction

6.5.3 Pressure release device action

1、check gas analysis and action reasons.

2、The pipe of respirator is smooth.

3、Check whether every accessory oil leakage or not

4、Check whether device cover is abnormal or not.

5、Secondary circuit fault .

Report shift-operator, inform maintenance personnel to take the body oil and gas

analysis. When the relief valve pressure recover, reset action bar by hand.

6.5.4 High reactor over temperature

a、Check if the thermometer and transducer fail or not, report shift-operator.


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b、Check whether overvoltage happen or not.

c 、 Unknown reasons abnormal increase, immediately report shift-operator, check and treatment.

6.5.5 Gas protection action

Heavy gas protection tripping, the reactor show internal failure without the reasons of

protection device secondary circuit failure, take gas and judge the fault characteristics

according to the characteristics of gas color, odor, flammability.

6.5.6 Light gas action may have the following reasons:

a、After oil filter, refuel, oil change, replacing the respirator silicone work, air enter reactor ;

b、The oil temperature drop or oil leakage;

c、Internal slight fault;

d、The secondary circuit or gas relay body failure;

e、Pipe joints leakage produce negative pressure, so air enters the reactor body.

6.5.7 After light gas action, not allow to put heave gas into alarm, report shift-operator ,

take gas analysis.

6.5.8 After light gas action or heavy gas tripping, find gas in relay and take the nature

gas, identify fault type, identification must be quick, otherwise the gas color will

disappear.

Gas identification table

Number gas property burning test fault nature

a colorless, tasteless no combustible air

b yellow nonflammable woodiness fault

c light grey combustible paper fault

d grey or black inflammable oil or core fault

6.5.9 When the line protection and reactor protection simultaneous trip, check both line

and reactor , not allow to power on without the accident reasons ,if it is necessary to


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power on , power on the line by force after quit reactor , at the same time must be

consistent with the provisions of reactor operation.

6.5.10 When heavy gas protection and differential protection trip together , not allow to

power on without the accident reasons .

6.5.11 Reactor heavy gas or differential protection trip, find the exterior no obvious fault,

and check the internal reactor normal by test, if necessary, you can try to power on.

6.5.12 Reactor fire, immediately open the circuit breaker, report to Pakistan fire

department and take other measures for putting out a fire . if fire is in the top of reactor ,

you should open the oil valve for oil drainage at the lower part ; if fire is in internal reactor

,not allow for oil drainage, prevent reactor a serious explosion.

6.5.13Found reactor interior serious explosion, fuel injection, smoke, fire, at the same

time report dispatcher to cut off the power supply, if necessary, inform the Palestinian fire

department. quickly organize personnel to put out fire by dry extinguisher fire. if

combustion is on the top cover of reactor, reduce the oil surface to appropriate position,

avoid the spread of fire. If the fire is inside the reactor, not allow for oil drainage, prevent

reactor a serious explosion.

7. Power trapper

7.1 Trapper inspection

a、Traps should be no bird's nest and deformation

b、No sound and acoustic

c、Wire clamp crimp firmly, good contact, no heating phenomenon

d、Trapper pillar porcelain insulator and insulator porcelain without damage and fracture

8. busbar 、framework

8.1 Summarizing

a、Busbar is the important equipment in substation, usually to strengthen the inspection, to ensure the safe operation. Thermal wax slices fall off and try to reinstall it in time, and

regularly measure by infrared temperature.

b 、 The busbar and the phase sequence connection wire arrangement should be consistent,twisting quality busbar should be marked

c、Busbar maintenance or long-term out of service, before operation, enable charging busbar protection to charging busbar .


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d、Switch room doors and windows should be closed tight and seamless; exhaust hole must be equipped with protective net. The hole of cable pass into the control room, guard

room, switch room and outdoor terminal box must be tight sealing, the cable cover intact,

in order to prevent the accident of small animal. The lime, brick or cement of the wall

should fall off and no crack. A house is without infiltration leakage phenomenon.

e、The necessary fire fighting equipment in substation should regularly inspect and test, not allowed to remove the fire fighting equipment for other purposes.

8.2 Inspection

8.2.1 The busbar and the connecting wire general inspection items:

a、Lead without broken strands, burn marks, no foreign body hanging down;

b、Wire clamp crimp firmly, good contact, no heating phenomenon

c 、 Architecture should be level and firm, anti-corrosion coating is good, no serious corrosion

d、Ceramic parts should be clean, no crack, discharge

e、Pipe type bus no serious deformation phenomena;

f、high 、semi-high bus frame type, the upper switch cable fixed reliable, prevent wind blown

g 、 Check the equipment lead, cross line frame, for other equipment and itself, have enough safe distance, to prevent the wind leaning fault.

8.2.2 The busbar and connection wire special inspection items:

a、when the annual steam temperature is high or low, check busbar sag meets the requirements;

b、When it snows, check the connector and wire conductive parts no ice or overheat

c、On gale weather, check the wire should be no severe vibration, swing and other phenomena, the wire should be no suspension;

d、On fog day, check the outdoor bus porcelain without discharge

f、High temperature or at the peak load, check bus and joints without overheating.

8.2.3 Regularly check the frame without tilting subsidence, no serious cracks and

weathering.

8.2.4 Steel frame parts coating are in good condition, the drainage hole is smooth, non

blocking, water and corrosion phenomenon.


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9. Lightning protection and earth device

9.1 Summarizing

9.1.1 In order to prevent lightning strike damage on substation electrical equipment and

building, the substation is equipped with a sufficient number of lightning rod. Independent

lightning rod and lightning arrester should be firmly grounded, should have a separate

grounding device, which connection to the total grounding grid can be disassembled, so

as to separately measure grounding resistance.

9.1.2 Lightning arrester counter should install every phase, not short circuit.

9.1.3 In order to ensure personal and equipment safety, all electrical equipment shell

must be grounded, and the total grounding connection, good grounding and marked

9.1.4 The substation grounding, lightning arrester should be periodically tested,

9.1.5 Check all kinds of lightning protection device grounding lead once a year before the

thunderstorm season.

9.2 Inspection

9.2.1 Lightning protection and earth device normal inspection

1、the lead wire clamp crimp firmly, good contact, no overheating phenomenon;

2、 lightning arrester porcelain should be clean, no cracks and discharge;

3、lightning arrester discharge recorder indicating correct and clear, look good,

4、the leakage current of the arrester and data indicating is correct ,date difference is no more than 10%;

5、the arrester skirt shielding lead connect well

6、lightning arrester insulation base porcelain without damage;

7、 equalizing ring installed firmly, non rust surface deformation;

8、no abnormal sound, discharge sound;

9、the lightning rod vertical, firmly, body intact, no serious corrosion, basic no subsidence and tilt;

10、the station grounding body no rust, firm connection.

9.3 Acceptance item after the overhaul

9.3.1 Test and maintenance of the project is complete meet the requirements of test

data.


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9.3.2 Field is clean, the lightning arrester without temporary short circuit wiring and other

legacy.

9.3.3 porcelain clean, no damage crack, wire fixation, metal pieces, no rust, shell

grounding wire welding firm.

9.3.4 Phase color signs right.

9.3.5 Arrester insulation base porcelain parts without damage, guide hole (or joint) and

ensure the smooth drainage.

9.3.6 Equalizing ring installed firmly, non rust surface deformation.

9.3.7 Lightning rod is firm and vertical.

9.4 Operation consideration matters

9.4.1 Strict implementation thunder season operation mode.

9.4.2 in the thunderstorm weather ,patrol persons on the outdoor high-voltage equipment

should wear insulated boots, and shall not be close to the lightning arrester and the

lightning rod.

9.4.3 Zinc Oxide arrester leakage current anomaly increases, more than 10%, should

strengthen the supervision; more than 20%, should be immediately reported shift-

operation.

9.4.5 Lightning arrester has one of the following faults, immediately stop and report shift-

operator.

1、lightning arrester porcelain rupture;

2、lightning arrester base support porcelain serious damage, crack;

3、 Arrester sounds abnormally;

4、connecting lead severe burns or fracture

10. AC system in substation

10.1 System configure and operation

10.1.1 In 500kV substation configuration ,there is two auxiliary transformer, one is from

6.6KV medium pressure chamber 6.6KV I/II segment, the other is from a diesel generator

to provide security section, diesel capacity is 400KW

10.1.2 the operation mode of power auxiliary system:


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1、normal mode of operation: working transformer provide for 400V PC I bus, security transformer provide for the 400VPC section II bus; PC II another power supply is from the

diesel generator, there is an interconnection switch between PCI/II section , the normal

operation is standby for each other between PCI/II section .

2、Working transformer maintenance or high side power loss, and the system without fault, start to close I/II buscouple CB automatically to supply I section and II section by

security transformer.

3 、 Security transformer maintenance or high side power loss, and the system without fault, start to close I/II buscouple CB automatically to supply I section and II section by

working transformer. When the work transformer do not take I/II section load , start

diesel generator to take PC section ,then open buscouple CB..

10.1.3 Automatic switching circuit: when security transformer power loss, and no short

circuit, automatically start I/II section buscoup CB, if fail, start diesel generator unit to

connect with the security section .

10.1.4AC, DC system number and application

1、The circuit breaker energy storage power: In local control cabinet, Q23 (R), Q33 (Y), Q33 (B), the energy storage power supply is from the LCC cabinet F401DC, the control

power supply is from the LCC cabinet of F11DC and F210DC. LCC DC power is from the

grid control 220VDC panel.

2、 The switch operating power: switch operating power supply in local control cabinet of QF1 (DC motor power supply), QF2 (switch control power supply of the power supply

cabinet) is from LCC F310DC, the control power supply is from the LCC cabinet of

F11DC and F210DC. LCC DC power is from the grid control 220VDC panel.

3 、 station AC power supply: AIS I/AIS II power supply respectively is from the 400V section I, Section II, AIS main power supply is used for local control cabinet temperature

control and station temperature control lighting

Station AC,DC power control and fault record power separately is from the 220VDC

panel and AIS power supply cabinet

DC power supply among protection panel

a 、 The first, secondary, third protection panel and busbar protection panel F110(protection power supply 1)F120(protection power supply 2) F100(lighting and

heating electric power) F102(cabinet socket)

b、Fault recorder and transducer F1(lighting and socket)F2(temperature control power supply)DK1(general power supply)DK21(device power supply)DK22(digital input

power)DK(device power supply)DK31(device power supply)DK32(digital input


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power)F3(busbar transducer power)F4(first bay transducer power) F5(secondary bay

transducer power)F6(Third bay transducer power)

10.2 Station system routine inspection

10.2.1 dry transformer inspection

a、Dry-type transformer coil temperature is normal, indicating the correct thermometer. 干b、Dry-type transformer sound evenly, no sound.

c 、 Dry-type transformer connecting lead, cable is without exception, each connection point no overheating phenomenon.

d、Dry-type transformer and the cabinet door are closed, not allow to open side door and back door , unless the rear has obvious abnormal sound, inspections are required to take

effective safety measures to open

e 、 Dry-type transformer operating voltage, operating current should be within a prescribed value.

f、On network control , room doors, windows, lighting should be intact, housing is not Water Leakage, normal temperature.

10.2.2Network control panel inspection items:

a、Station system operation mode and each branch running indicating status should be

normal. b、loop power is open-loop correctly, a warning sign.

c 、The instrument indication is current, each branch switch position is correct, consistent with operational requirements.

d 、 No abnormal noise, no smell, no smoking, no overheat phenomenon. e 、 cabinet screen doors should be closed tightly.

f、Panel clean, cable seal well.

10.3 Operation

10.3.1 dry-transformer operation

a 、 On normal operation , temperature of dry-type transformer can not exceed 100 degrees, fan automatic startup temperature is 100 degrees , the premise of the fan

control mode is in automatic mode, the fan stops running at 80 degrees, the transformer

temperature alarm setting in 130, temperature trip in 150.

b、The running voltage shall not exceed 105% of the corresponding tap rated voltage.

c、Dry-type transformer can be run in the normal overload and fault overload conditions.

10.3.2 Station power operation


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a、In normal conditions, operate high voltage side CB in ECS mode, then operate low voltage side CB by hand.

b、Try transformer power cut sequence is from high to low, power no sequence is on the contrary.

c 、 After dry transformer maintenance, check everything normal ,then charging dry transformer through high voltage CB.


10.4.1 Two dry-type transformers shall not be run in parallel; load circuit of two different

dry-type transformers shall not be in parallel .

10.4.2 Working dry-type transformer shutdown, check the no voltage indication, make

sure that the secondary working switch open, then close the spare transformer

secondary switch.

10.4.3 Before section switches close, make sure busbar inlet switch is in open position.

10.4.4 Power switchover or power failure recover, check the charger and inverter device

is normal.

10.4.5 Voltage should be maintained at (1 ± 5%) Un, when the voltage is too high or too

low, promptly report shift-operator.

10.4.6 The new operation dry-type transformer or voltage loop was removed after wiring

work, carry on phase check

10.4.7 The dry-type transformer shutdown before obtain shift-operator agreement.

10.4.8 Automatic switching function can not distinguish about 400V busbar fault,

disenable automatic function.

10.5 Abnormal and accident treatment

10.5.1General principle for abnormal or accident treatment.

a、When electricity is lost, check the cause as soon as possible, isolate the fault point, restore the power supply as soon as possible, give full consideration to have influence

on important load .

b、Station power fault trip, not find obvious fault point, make measures to check step by step, find the fault branch, isolation repair as soon as possible.

12.5.2One of the follow cases happen ,report shift-operator to outage

a、The internal noise is large, not uniform and a popping sound;

b、In the normal load and cooling conditions, temperature is not normal and rising;


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c、Station transformer bushing has serious breakage and discharge phenomena;

d、Station transformer fire.

10.5.3 Station transformer high voltage side fuse is broken, first transfer the load, replace

the fuse after no obvious abnormality; fuse is broken again, immediately power outage,

find out the reason and eliminate the fault, then put into operation.

10.5.4 Station transformer secondary switch will trip, identify the reasons. If automatic

switching function succeeds, check the operation signal, the switch position and the

related equipment and make records, report to shift-operator. If auto switch fail , check

the loss 400V busbar without obvious fault, try to power on again, if fails again, find out

the fault branch , then isolate the branch, restore the other branch transmission.

10.5.5 Air switch is tripping or fuse is broken, check the fault circuit, not find obvious fault

point , try to power, if fail , not allow to power on, before finding out the reason and

eliminating the fault, not allow to transfer to another busbar , avoid accident expansion.

10.5.6 When station power system voltage is too high or too low, promptly report shift-

operator to check 6.6KV voltage, if 6.6KVvoltage is high, inform operator for regulating

tap-changer to a proper position; if voltage regulation reach to the limit position, the

6.6KV voltage is still too high or too low, promptly reported shift-operator to regulate

main transformer tap-changer.

11. Substation DC system

11.1 System configure and operation mode

11.1.1 220V DC system has two sections of DC busbar, three chargers. No. 1 charger

connect to section I busbar, charge first battery group; No. 2 charger connect to section II

bus, charge second battery group; No.3 charger can take section I or section II DC

busbar, also can charger the first battery group or second battery group . Under normal

circumstances, No.3 charger is standby, when 1 or 2 charger failure, No. 3 charger start

to run.

11.1.2 220V section I,II DC busbar connected with the main load : protection device 、 automatic device 、 circuit breaker energy storage control power supply 、isolator control

power supply 、central signal circuit power supply 、relay protection test power etc.

11.1.3 Battery normal operation mode is in floating charging mode, charging current =

load current + float current .

11.2 Operating provision

11.2.1 DC system routine inspection and maintenance


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11.2.1.1 Check DC busbar positive to ground、negative to ground and insulation resistant normal .

11.2.1.2 Check charger current normal

11.2.1.3 Check battery normal

1) The battery connection sheet is without loose and corroded, shell is without leakage

and deformation, no acid mist leakage is around the pole and the safety valve.

2) Monomer battery voltage、 insulation resistance and the battery temperature is normal.

3) Battery monitoring device is without warning signal, if the alarm message display

battery number, measure the monomer battery terminal voltage

11.2.2 The floating charging operation should go to equalizing charging operation every

six months; microcomputer equipment can be set to automatically according to the cycle

setting.

11.2.3 No 3 charger should be on switching test quarterly, ensure it is in good condition.

11.2.4 The new installation valve control battery should be carried out to discharge, after

every 2 to 3 years, go on a checkup charging and discharging test. After six years , do

the charging and discharging test once a year .

11.2.5 On operating fuse, remove the positive power supply fuse ,then take the negative

power fuse. When power on, then put the negative power fuse and then put a positive

power fuse.

11.3 DC grounding treatment

11.3.1 DC system grounding may cause the protection misoperation, to eliminate the

fault as soon as possible.

11.3.2 DC system grounding, operator should record the time, the grounding pole,

grounding branch number and insulation resistance value, report shift-operator.

11.3.3 After DC grounding, immediately stop relevant work, check whether the station

work cause the DC grounding or not.

11.3.4 After the DC grounding, the relay protection engineers use special instruments to

find. In case of emergency, report shift-operator and dispatcher, methods can be used to

pull each branch for test, pull the first branch, the ground can not disappear and then pull

another branch. in accordance with first common and then important principle, the details

are as follows:

1、Not affect the normal operation, or the influence smaller.

a、Working circuit


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b、Hot standby circuit or cold standby circuit.

c、Non protection and control circuit in DC busbar , such as inverter, battery, charger, power supply, central signal power and so on.

2、Influence on the normal operation circuit, when pull the branch, report the dispatcher, the DC power loss time should be as short as possible

a、Just operate circuit.

b、Fault recorder.

c、Circuit breakers control circuit, double trip coil circuit breaker should be tried to pull each branch step by step.

d、DC power of double protection configuration or element protection should be test, pull two groups DC step by step, for line main protection, first ask shift-operator whether the

main protection operation quit or not.

e、DC power of only a set of protection configuration circuit or element protection, for line main protection, first ask shift-operator whether the main protection operation quit or not.

f、The busbar differential circuit and other important circuit, be care for safety.

11.3.5 Consideration matters with dealing with DC grounding

a、Pull branch method is used to locate DC grounding position, at least two people work.

b、Not allow to stop network control DC power supply .

c 、 On DC system grounding, not allow to work in DC system, except for the relay protection engineers, the other person should immediately stop working.

d、On a lightning storm weather, prohibit to find out the DC grounding.

11.4 Net control system operation procedure

1, 1# charger is put into use by the following order

First switch on AC line switch 1ZK, check AC three-phase voltage is normal, close the

AC input switch 1Q1 to start the charger, the charger output stable DC, and then close

the DC output switch 1Q2, then 1GS (AUTOMATIC CHANGEOVER) switch (A) (the dual

power switch) close by judging the condition, then close the battery switch GH9, then

complete the boot process and charger to charge the battery pack. Then close the GH5

and 1DQ (the switch is completed by AUTOMATIC INTERLOCKING), then the charger

and battery is through the voltage regulator (1TY, GH5), supply stability DC power by

1DQ.

2、2# charger is put into use by the following order


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First switch on AC line switch 2ZK, check AC three-phase voltage is normal, close the

AC input switch 2Q1 to start the charger, the charger output stable DC, and then close

the DC output switch 2Q2, then 2GS (AUTOMATIC CHANGEOVER) switch (A) (the dual

power switch) close by judging the condition, then close the battery switch GH9, then

complete the boot process and charger to charge the battery pack. Then close the GH6

and 2DQ (the switch is completed by AUTOMATIC INTERLOCKING), then the charger

and battery is through the voltage regulator (2TY, GH6), supply stability DC power by

2DQ.

3、3# charger is put into use by the following order

First close AC line switch 3ZK , check three AC voltage is normal , close AC input switch

3Q1, start charger, monitor stable DC output by charger control model . Then close DC

output switch 3Q2. This moment no.3 charger starts completely.

4、When 1# charger failure occurs, the 1GS switch (A) automatically open, then switch to (B) by 3# charger with 1 batteries and 1 bus. The whole process : 3ZK → 3Q1 → 3Q2 →

1GS (B) → GH1 → 1TY → GH5 → 1DQ.

5、When 2# charger failure occurs, the 2GS switch (A) automatically open, then switch to (B) by 3# charger with 2 batteries and 2 bus. The whole process : 3ZK → 3Q1 → 3Q2 →

2GS (B) → GH2 → 2TY → GH6 → 2DQ.

6、When 1#、3# charger failure occurs, 1GS switch(A、B) is open , 2# charger take 2 battery and 2 section busbar, at the same time charge 1 battery and take 1busbar , the

whole process:

2ZK→2Q1→2Q2→2GS(A)→2TY→GH6→2DQ

↓

GH4→GH3→1TY→GH5→1DQ

7、When 2#、3# charger failure occurs, 2GS switch(A、B) is open , 1# charger take 1 battery and 1 section busbar, at the same time charge 2 battery and take 2 busbar , the

whole process:

1ZK→1Q1→1Q2→1GS(A)→1TY→GH56→1DQ

↓

GH3→GH4→2TY→GH6→2DQ

8 、 :When 1TY fault in 1# DC regulation panel, 3TY in 3# DC regulation panel take 1 busbar, the whole process:

1Q1→1Q2→1GS(A)→GH3→→3TY→GH7→1DQ。


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9 、 When 2TY fault in 2# DC regulation panel, 3TY in 3# DC regulation panel take 2 busbar , the whole process:

2Q1→2Q2→2GS(A)→GH4→3TY→GH8→2DQ。

10、When 1TY and 3TY fault in correspond regulation panel, 2TY in 2# DC regulation panel take 1 busbar and 2 busbar, the whole process:

2Q1→2Q2→2GS(A)→2TY→GH6→2DQ→3DQ。

11、When 1TY and 3TY fault in correspond regulation panel, 1TY in 1# DC regulation panel take 1 busbar and 2 busbar, the whole process:

1Q1→1Q2→1GS(A)→1TY→GH5→1DQ→3DQ。

Note: operation refers to DC system drawing.

12. Accident treatment

12.1 General principle of accident treatment

12.1.1 Primary mission of accident treatment.

a、Try to limit accident development; eliminate cause of accident and relieve personal and equipment safety threat;

b 、 Maintain the equipment running as possible as can, ensure the power supply is

normal; c、Quickly restore normal power supply;

d、adjust the device operation mode, restore normal operation.

12.1.2 In dealing with the accident, the operator on duty shall comply with the dispatcher

command (according to general equipment scope, if necessary, report the advanced

shift-operator), rapidly implement the order. With relate to a significant impact on system

operation, must obtain Pakistan dispatcher order. In accordance with the following items,

deal with it first, and then report Pakistan dispatcher in details:

a、Power with direct threat to persons and equipment is outage.

b、Ensure no power, the damaged equipment is isolated;

c、The operating equipment have been damaged, according to the relevant provisions of the regulations, the equipment be deactivated or isolated;

d、When the bus voltage disappears, switch off the busbar each branch CB (except the specified circuit breaker );

e、When the part or all of electricity is blackout, restore the power supply.


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12.1.3 When Handling the accident, strictly implement “issuing an order, repetition,

recording and reporting system”, you must use the unified terminology and operational

terms, report content should be concise .

12.1.4 The system accident occur, the operator on duty immediately report the relevant

duty of dispatcher , after clarifying the cases, report detail content as soon as possible .

Report content should include time, trip circuit breaker, relay protection and automatic

device (especially the protection action element), the fault phase, frequency, voltage,

distance and the trend of the current.

12.1.5 Treatment procedure after accident.

12.1.5.1After the accident, immediately report the relevant dispatcher about the time of

accident, the main protection action and abnormal signal, the trend of current, frequency,

voltage and so on.

12.1.5.2 The operator carrying on the following items immediately.

a、Reset sound signal, recording the time, check the meter indication;

b、Check the emitting signal and make record, reset the signal;

c、Check the relay protection and automatic device action signal and make record, reset the signal;

d、Check and print action report of relay protection and automatic device,

e、External examination for the tripping or failure equipment;

f、Reset the trip circuit breaker;

g、Record CB trip times.

12.1.5.3 After checking primary or secondary equipments, report shift-operator about

details inspection. Its contents include:

a、The primary or secondary equipment accident state;

b、Relay protection and security automatic equipment operation analysis;

c、The site treatment suggestions and measures will be taken.

12.1.5.4 According to the dispatching command, isolate the fault point, recover

equipment power.

12.1.5.5 Report the relevant leader about treatment result, arrange maintainer to repair.

12.2 Line accident treatment


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12.2.1 Line accident trip (including single-phase reclosure fails), allow to charge again, it

must be issued by the dispatcher. The time interval shall not be less than 15 minutes.

12.2.2 Before powering on fault line (including circuit breakers, switches, flow, pressure,

coupling capacitors, trapper, and lightning arrester equipment), check external circuit

carefully, and find no obvious fault, then power on line again.

12.2.3 Power on transmission line by force shall meet the following conditions:

a、Circuit breaker circuit and operating mechanism is intact and normal, SF6 pressure is normal;

b、circuit breaker fault tripping times is within the permissible range;

c、relay protection is intact.

12.2.4When the 500KV line protection and reactor protection simultaneous trip, check

both line and reactor , not allow to power on without the accident reasons ,if it is

necessary to power on , power on the line by force after quit reactor , at the same time it

must be consistent with the provisions of reactor operation.

12.3 Busbar fault and loss treatment

12.3.1 busbar fault treatment

12.3.1.1 The busbar fault refers that the busbar fault occur, busbar differential protection

act, trip all the circuit breaker on the busbar, current meter and power meter is zero, the

bus voltage meter disappears, and check the relevant protection action signal.

12.3.1.2 When the busbar fault occur , the operator on duty should be immediately

reported to the relevant shift-operator. And open all circuit breaker fault on the busbar ,

report shift-operator again.

12.3.1.3 When the busbar loss power because of busbar fault, operator on duty goes on

external inspection, report shift-operator, operator on duty shall be treated according to

the following principles:

a、find the fault point and be quickly isolated, recover power before isolating fault.

b、find the fault point through the examination, the fault bus was powered on by external power supply.

c、f trying to power on by internal power supply, the circuit breaker must be intact, and relay protection is good, busbar or main transformer backup protection is with sufficient

sensitivity, if necessary, shorten the backup protection time of main transformer, so as to

ensure the sensitivity and rapidity.

12.3.2 busbar power loss treatment


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1、The busbar power loss refers that the busbar voltage disappear because of fault on system. Protection is incorrect tripping to make circuit breakers no action , then override

trip occur. Discriminating bus loss of power is based on the following phenomena at the

same time:

a、the bus voltage meter indication disappear;

b、the bus electricity lost.

C, after substation bus electricity lost, operator open all the CB on the busbar, except for

the circuit breaker prescribed, and report shift-operator. if trying to power on busbar , use

external power supply as far as possible.

d 、 after substation bus electricity lost , operator on duty analyze electricity reasons,

according to circuit breaker failure protection、outlet line and main transformer protection action message ,report the shift-operator about action analysis.

12.4 Resonance overvoltage treatment

12.4.1 The perceptual, capacitive elements, under certain conditions may form a

resonant circuit during operation or grid fault, the resonant overvoltage will produce

overvoltage, and it damages the equipment. Causes of resonance overvoltage are as

follows:

a、Intermittent arc grounding fault is caused by ferroresonance overvoltage;

b、the bus charging, electromagnetic voltage transformer and bus capacitance to ground is caused by resonance over voltage;

c 、 Shunt capacitor of the hot standby circuit breaker and the uncharged bus electromagnetic voltage transformer in the uncharged bus cause resonance overvoltage.

12.4.2 A phase, two-phase or three-phase voltage of the resonance characteristic

exceeds the line voltage, the other phase voltage drop.

12.4.3Key to treat resonance overvoltage accident breaks the resonance condition.

When the resonance over-voltage occurs, based on the grid and operation situation,

rapidly judge and treat

a 、 not allow to close circuit breaker with the equalizing capacitance and reasonable power.

b、Charging no-load transformer or a passive line in the empty bus, also open power side isolator. The operation can be controlled in remote mode, not allow to control in local

mode, prevent the resonant for explosion to harm people.


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c、Resonance overvoltage continues for a few minutes, even if the test is up to standard, PT should also be out of operation. Equalizing capacitor and arrester that is the parallel

in PT should strengthen inspection and surveillance.

d 、 when the resonance occurs on operation, immediately open an unimportant load, change the system parameter to eliminate resonance.

13. Operation and management of general relay protection

and automatic safety device

13.1 Management provisions

13.1.1 Protection and automatic device in service shall meet the following conditions

a、Have the right, practical principle diagram and secondary wiring diagrams.

b、Have approved protection setting sheet, and check the setting sheet is consistent with the device setting.

c、Label of field device name, plate, select switch and the terminal box, control cabinet, fuse and button is exact and complete.

d、Miscompute protection configuration management device, measures should be taken to lock remote setting modification, logic and other functions.

13.1.2 After relay protection working, the operator check and accept work, if qualified,

transact the job termination procedures, approval shall be conducted in accordance with

the following requirements

a、When accepting the work, listen to the person in charge of the work introducing about the work. There is no setting change, wiring changes, and operator attentive items, if

necessary, check the control drawing, and then approve according to the actual situation

of work.

b 、 When accepting the work, the following test items is done, “ simulate fault test, transmit test, and check the device signal, circuit breaker action correctness , automation

device information correctness”, if it is in doubt, inquire the person in charge of the work

explaining about the work .

c、Secondary wiring changes, ask the person to modify the drawings, mark name and modification date, check the actual wiring correct together with the person in charge of

work.

d、Device setting is correct.


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e 、 If the device has defects, report the professional person in charge and supervisor department, allow running after agreement.

f、After the approval, check the protection panel clean without debris, disconnected wiring shall be restored.

g、The person should make a record, the content should be consistent with the actual job. Pay attention to the notice matters of the device, it should be detailed in the work

record.

13.1.3 In addition to relay protection system operating mode, allows the exit and

automatic device, the normal operation of the electrical equipment shall be no protection

operation. Relay protection and automatic device must be operated by Pakistan

scheduling instruction execution (switching operation process in order to prevent short

time except the misoperation of protection disabled).

13.1.4 In order to achieve safety isolation, reduce the requirements of site operations,

shift-operator give an order about protection out of service except for the remote low trip

channel; only put protection into alarm status. On operation device running, operator will

turn over protection alarm status to maintainer, after the job is complete, maintainer will

transfer the original status to the operator.

13.1.5 he circuit breaker is in the running state, not need to measure before

microcomputer protection output plate is in service, but check the device without action

and abnormal signal.

13.1.6 Modified protection setting should be based on the dispatcher command, operator

go on switching operation in the setting area of device. Setting switching operation in

microcomputer protection does not need to stop protection mode, but relate to the setting

revision, the protection engineer should stop protection mode, then revise the setting.

13.1.7 An equipment shutdown, the dispatcher generally does not give an order about

disabling the protection device. Based on a state of equipment and operation

requirements, the operator makes the corresponding adjustment to the secondary circuit.

The principle is that primary equipment shutdown and the corresponding secondary

protection out of service, not allow to stop less or more secondary protection .

13.1.8 Maintenance 、 test and checkout have influence on running equipment ,the operator should fill with safety measures ticket and take safety measures, but only limit to

the protection plate, switch and other operations. Relating to terminal block wiring circuit

is completed by the relay protection engineers.

13.1.9 In the busbar differential circuit ,when circuit breaker of 3/2 connection busbar side

need to be repaired ,try to close circuit breaker for a test , prevent the busbar differential

misoperation after primary loop closing , should short the relevant CT circuit of the circuit


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breaker, recovery before putting into operation. When the CT circuit is without link, the

work was done by the protection engineers; CT circuit has a link, the works is completed

by the operator, and fill in the safety measure ticket.

13.1.10 A fuse in the control and protection circuit shall be placed according to capacity;

the fuse should have corresponding specifications.

13.1.11 When the protective device and the communication are on multiplex channel,

channel maintenance and debugging equipment shall be responsible for the

communications personnel. When the communication workers affect the normal work of

relay protection device work in the communications equipment or multiplexing channel ,

communication personnel should inform the operator, operator report Pakistan shift-

operator ,after Pakistan shift-operator agreement, give an order to operator to stop relay

protection device running , make sure that everything is safety .then the operator informs

the communication person to start work.

13.1.12 In order to prevent the maloperation of protection, not allow to use wireless

communication device .

13.1.13On the cleaning work of the protective panel, you should use the appropriate tools

to clean, the action should be careful so as to avoid misoperation.

13.2 Normal inspection

The operator should inspect relay protection 、automatic safety device and secondary terminal box according to the relevant provisions , items are as follows:

a、the power switch is operated correctly;

b 、 secondary connection no loose and overheat, current terminals without sparking phenomenon;

c、the device status is normal, the indicating lamp and the switch position is correct, the microcomputer protection clock should be accurate;

d 、 LCD screen display is normal, CPU operation is normal, protection device communication is normal;

e、the protection setting area is in correct position;

f、internal device is no abnormal sound 、 acoustic、 no smell and no serious overheat;

g、the main protection channel test or check was normal;

h、the printer should be normal, printing paper enough;

i、the cabinet door seal well and no rust, inside cabinet is clean and well grounded.

13.3 Operating instructions


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13.3.1 500KV line protection

13.3.1.1 High frequency protection on both lines side has always maintained a consistent

state.

13.3.1.2 If the line is still operation, quitting line high frequency protection shall be

approved by the Palestinian the dispatcher.

13.3.1.3 When the 500kV line outage and one of the circuit breakers on both side will

resume operation state, stop the remote tripping mode , high frequency direction

protection is changed into non channel trip, differential protection is put into signal, the

short line protection is enabled.

13.3.1.4 About backup protection for 500kV transmission line ( backup distance, direction

zero sequence)

a 、 if the backup protection (including backup distance and direction zero sequence) contained in the line main protection (differential current, high frequency distance or

direction high frequency), the dispatcher do not issue an order ,such as the line main

protection is put into signal, the corresponding backup distant and the zero sequence is

for signal state.

b 、 if the backup protection (including backup distance and direction zero sequence)is independent of line main protection, under normal circumstances, the dispatcher do not

issue an order ,such as the line main protection is put into signal, the corresponding

backup distant and the zero sequence is for signal state. Only when the backup distance

(or the direction zero sequence) device is fault, need to stop treatment, Pakistan

dispatcher confirm backup distance (or the direction zero sequence) device fault, then

issue an order about putting backup distance (or direction zero direction) to signal state.

13.3.2 500KV circuit break protection

1, Circuit breaker on 500kV bus side is with reclosing priority logic circuit, if the circuit

breaker on the busbar side shutdown, operator should relieve circuit breaker reclosing

priority logic. Conversely, when the circuit breakers on bus side is in service, restore the

reclosing priority logic.

2, when reclosing configuring is arranged according to the CB arrangement, except for

the alone disable reclosing requirements, the dispatcher issue an order according to the

circuit breaker numbers, the rest disable reclosing requirement according to the line

name.

3、The dispatcher disable or enable line reclosing mode

A、Line protection with tripping select switch

1）Put line tripping mode into three phase tripping position.


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2）The relevant CB reclosing changed into alarm status, in details as follows

a) Line and transformer bay or incomplete bay: two circuit breaker reclosing mode on line

side is put into signal state;

b) Line and line bay: two circuit breaker reclosing mode on busbar side is put into signal

state;

B、Line protection without tripping select switch

1）Two circuit breaker reclosing mode on line side is put into signal state;

2 ） When single phase grounding fault happen in a line, the middle CB can not be reclosing, immediately report the dispatcher to close the middle CB by hand.

13.3.3 The whole protection is disabled, disconnect outlet link the in control circuit. If

protection part function exit, quit part function input link or mode switch, not allow to quit

output link.

13.3.4 500kV bus differential protection 、 main transformer protection、 reactor protection

、 remote tripping 、circuit breaker failure protection device have self-hold circuit, before put into tripping , regardless of whether the device has no action signal, press the reset

button to prevent self-hold cause equipment trip.

13.3.5 500KV CB changed into manual function, not allow stopping protection DC power

supply, preventing CB protection refusing action.

13.3.6 When circuit breaker is changed into cold standby, or maintenance mode, not

allow to stop interlock tripping output link. In order to prevent mechanical wounding,

switch on the circuit breaker control power supply, the responsible person apply for

operator, operator is in charge of operation. According to the actual working condition,

interlock tripping operation fill on safety measures ticket

13.4 Abnormal operation treatment

13.4.1 One of the follows cases happen ,immediately report the dispatcher and shift-

operator, quit relay protection and auto device

a、device smoke and fire

b、inside device appears discharge or abnormal sound;

c、device deformation and overheating;

d、the other can cause significant misoperation or refusing action dangerous situation.

e、device appear severe fault not return.


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13.4.2 Microcomputer protection device appear fault, immediately report the relevant

shift-operator and dispatcher, disable concerning protection, restart device. Observe the

device is normal in a period of time, restart the device again .if not normal, and report the

dispatcher and shift-operator to deal with it.

14. 500KV Main transformer protection

14.1 Summarizing

14.1.1 Generator –transformer protection have two panel , the first panel is connected to

No1 DC power supply, the secondary panel is connected to No2 DC power supply

14.1.2 There is below devices in the first panel.

1、The whole differential protection;

2、500kV side distance protection;

3、Main transformer protection (including OLTC) A, B, C three-phase;

4、Low side over current protection ( );Ⅰ

5、500kV side overload protection;

6、Over excitation protection.

14.1.3 There is below devices in the secondary panel.

1、The high impedance differential protection;

2、The generator-transformer differential protection

3、The neutral point zero sequence current protection;

4、Overload protection;

5、Low side over current protection (II);

6、The neutral excursion protection;

14.1.4The voltage loop and current loop, and action situation of 500kV main transformer

protection (field trip condition is decided by the setting sheet)

14.1.5 Non electric quantity protection of main transformer does not start failure, the rest

of the electrical protection trip were to start failure protection.

14.1.6 The following non electric quantity protection has the drop signal.

1、Body heave gas relay: Tripping.

2、Body pressure release: Tripping or signal. According to the actual setting to set;


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3、Oil pressure mutation: Signal.

4、The wind temperature high: Signal.

5、Oil temperature high: Stage 1 is used for signal, stage 2 is used for tripping, stage1 output block stage 2 output.

6、OLTC heavy gas: Tripping.

7、OLTC pressure release: Signal.

8、Cooler full stop: Signal.

9、The body light gas: Signal.

10、The body abnormal oil level signal: Signal

11、The OLTC level anomaly: Signal.

14.2 Panel introducing

14.2.1 The drop signal and signal light indication

14.2.2 Switch and button

1) The main DC power switch (with the exception of body protection) normally is in

closing position.

2) Body protection DC power switch normally is in the closing position.

3) DC power supply switch of 500kV distance protection have two positions, normal

operation should be in the "on" position.

4) 500kV distance protection has setting selection switch.

5) The total reset button "RESET" is used to reset double position relay .

6) 500kV distance protection voltage switch.

7) The reference voltage switch of 500kV distance protection .

14.3 Normal operation

14.3.1 during normal operation, check the DC power supply switch of protection device

should be closed, running lights is normal, the selector switch position on the panel

should be consistent with the dispatcher orders, no drop signal on protection device. The

components are normal, no abnormal, no sound and smell.

14.3.2 The tripping protection (including the whole differential, high impedance

differential, backup distance, over excitation protection, , low voltage side over

current ,the neutral point zero sequence) has three running status:


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1、trip: AC, DC circuit of protection device is normal ; trip output circuit is normal.

2、signal: AC, DC circuit of protection device is normal; trip output circuit is open.

3、stop: AC, DC circuit of protection device is disabled; trip output circuit is open.

14.3.3 only signal protection (including the main transformer 500kV side overload, the

neutral point excursion protection), the dispatcher do not issue an order, use the

operating license mode.

14.3.4 Not Pakistan issuing setting (such as the main non electric quantity protection),

the dispatcher do not issue an order, use the operating license mode.

14.3.5 Check protection device is no action and abnormal signal before protection device

start. Abnormal protection or working on protection must be disabled, consider the

transformer stop running. if the transformer can not stop, it must get the consent.

14.3.6 500kV distance protection as a back-up protection 500kV, when the

corresponding busbar protection is disabled, adjusts the distance protection action time.

15. High voltage reactor protection

15.1 GE reactor protection

15.1.1When the high reactor protection trip, trip this CB and at the same time send a

remote tripping order, trip the opposite CB. External lead fault of reactor will be tripped

by line protection .

15.1.2 High protection configuration

1、The split phase current differential protection: the split phase differential protection use secondary current sum of high voltage bushing and the low voltage bushing as a

differential current, protect against reactor internal faults.

2、Zero sequence differential protection: zero sequence differential protection also uses secondary zero current sum of high voltage bushing and the low voltage bushing as a

differential current, protect against reactor internal single grounding faults.

3 、 Device is also equipped with back-up protection: including the negative sequence directional protection, over current protection, overload protection.

1) The negative sequence directional protection use line secondary voltage and

secondary current of high bushing and low bushing to determine whether the fault is

inside reactor. After the protection action, delay tripping.

2) Over current protection use secondary current of high bushing to determine whether

the fault happen in reactor, after the protection action, delay tripping.


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3) Over load protection, using secondary current of high voltage to judge whether reactor

is overload. (Overload caused by overvoltage) after protection action, delay signal.

4 、 non electric protection, including light, heavy gas protection and pressure relief protection etc..

15.2 panel introduction

15.2.1GE company reactor panel introduction

There is DC power supply in reactor protective panel , F110 is protection device power

1, F120 is protection device power2, both DC power supply are normally put into service

,there is automatic switching power supply device inside the device , No1 power outage

automatically switches to No 2 power.

15.2.2 Auxiliary relay HAA drop signal need to reset by hand,

1. Main reactor heavy gas action;

2. Main reactor pressure release action


15.3.1 During normal operation, check the DC power supply switch of protection device

should be closed, running lights is on, the selector switch position on the panel should be

consistent with the dispatcher control state, there is no abnormal phenomenon and drop

signal in device. each components is normal, no sound and smell.

15.3.2 The tripping protection device(include high reactor differential, zero differential ,

pressure relief protection and so no) have two running status .

1, trip: AC, DC circuit of protection device is normal; trip output circuit is normal.

2, signal: AC, DC circuit of protection device is normal; trip output circuit is open.

15.3.3 only Signal protection(including reactor grounding detection, over load and so on),

the dispatcher do not issue an order, use the operation license mode.

15.3.4 Not Pakistan issuing setting (such as reactor body protection), the dispatcher do

not issue an order, use the operating license mode

15.3.5 Check protection device is no action and abnormal signal before protection device

start.


15.4.1GE company reactor running consideration matters

1 、 Reactor is out of operation. Whether the primary system has work or not, reactor protection must be out of service.


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2、Reactor is out of operation, but line is in service, before any job in protection panel must be done, take off inserted PK so as to disconnect the reactor protection with the

outer circuit connection.

3、After the inserted PK in Reactor protection panel is pulled out, disconnect the control loop.

15.5 Abnormal judgment and treatment

15.5.1 Device sends "DC disappears" signal, check whether small DC switch in

protection panel and small DC switch in DC power distributed panel is tripped or not. If

the DC power switch is tripped, immediately report the dispatcher and shift-operator to

disable protection, try to power on the relevant circuit, if it is not successful, rapidly inform

special person to deal with it.

15.5.2 If “device abnormal signal”is coming , check the relevant information, to judge. If

the device is not restored, report to the dispatcher and shift-operator, quit the protection

and deal with.

16. 500KV short lead protection

16.1 Summarizing

16.1.1 Short lead protection is a current protection, when the line / transformer shutdown

and circuit breakers is on loop closing operation , used to protect from the outlet line

switch to the lead between the CT of two circuit breaker. The short lead protection is

blocked through the outlet switch auxiliary contact, if the outlet switch is closed, the short

lead protection exit, if the outlet line switch is open, short lead protection is automatic

input.

16.1.2 There are two sets of short lead protection in 500KV transformer inlet line panel,

the protection type is F650 that made in GE, and outlet short lead protection is inside line

differential protection and distance protection device

16.1.3 two sets of short line protection and two sets of line protection share a set of CT

secondary sum current. Two sets of main transformer short lead protection and

transformer differential protection all share a set of CT secondary sum current.

16.1.4 Short lead protection configuration

Type F650 short lead protection is produced by GE company, which is a microprocessor-

based three-phase three - stage current and zero sequence current protection. if line

switch is opened or selector switch is in on position , short lead protection is in service, if

line switch is closed and selector switch is in off position, short lead protection is out of

service.


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16.2 Panel introduction

16.2.1 F650 type short lead protection device

1、The DC power supply switch is normally closed.

2、Green running light (In Service) is normally bright.

3、Yellow start lamp (Start)is bright when protection starts.

4、Red action lamp (Trip) is bright when protection act, need to manually reset.

5、The LCD screen.

6、In the small keyboard, there is“→”、“←”、“↑”、“↓” four direction key and the "E" confirm button .

7、The reset button is used for resetting and start-up .


16.3.1 during normal operation, check the DC power supply switch of protection device

should be closed, running lights is bright, the selector switch status on the panel should

be consistent with the dispatcher control status, Operation of the components is normal,

on sound and smell.

16.3.2 Short lead has three control status

1、Trip: AC, DC circuit of protection device is normal ; trip output circuit is normal.

2、Signal: AC, DC circuit of protection device is normal; trip output circuit is open.

3、Stop: AC, DC circuit of protection device is disabled; trip output circuit is open.


16.4.1 Short lead protection function is automatically controlled by the outlet switch

auxiliary contacts, tripping output function according to operation or shift-operator

command.

16.4.2 During line normal operation, in order to prevent short lead protection

automatically input due to line switch auxiliary contacts problem, disconnect short lead

protection tripping outlet. Line shutdown, before the circuit breaker is on closing loop,

check the short lead protection tripping bright, short line protection is in service.

16.4.3 Some short lead protection is still on self-hold status after the circuit breaker trip,

reset the protection by hand before CB is put into service .

16.5 Abnormal judgment and treatment


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16.5.1 Device sends "DC disappears" signal, check whether small DC switch in

protection panel and small DC switch in DC power distributed panel is tripped or not. If

the DC power switch is tripped, immediately report the dispatcher and shift-operator to

disable protection, try to power on the relevant circuit, if it is not successful, rapidly inform

special person to deal with it.

16.5.2 If “device abnormal signal” disappear , check the relevant information, to judge. If

the device is not restored, report the dispatcher and shift-operator, quit the protection and

deal with it.

17. 500KV fault recorder

17.1 Summarizing

The ARR800 integrated data monitoring system which is used for 500kV system fault

recorder is made in ACHENG company, china , the system is composed of DAU (data

acquisition unit), LSU (local storage unit), printer, PC, MODEM, HUB and GPS etc..

Fault recorder with REPLAYTM PLUS software can realize network communication, data

analysis, display, and management etc..

17.2 Fault recorder operation provision

1、Fault recorder must be put into operation, on the operation of equipment, if you want to exit, report the dispatcher to apply for approval .

2、DC power supply and AC power supply of fault recorder AC should be closed.

3、When fault recorder happens to alarm signal, check the printer output content.

4、after the incident each time , the operating personnel inform relay protection engineers to print out the fault report and check fault recorder action, before printing recording data,

DC power supply and plug –in are out of service .

17.3 fault recorder signal

1、 Panel signal

Hathaway watchdog warning: when DAU failure or power disappears.

Hathaway trigger: when the fault recorder trigger.

2、Central signal (protection device to DCS signal)

Device fault: when device is abnormal.

Fault recorder start: when fault recorder start recording.

Power fail alarm: when DC and AC air switch tripping.


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Voltage alarm: when secondary voltage air switch trip.

Note: GE code function

25 Synchronism check

27P Phase undervoltage

27X auxiliary undervoltage

32 direction power

32FP forward power

32N direction zero sequence power

46 negative sequence delay over current

47 negative overvoltage

48 locked rotor

49 over load with thermal model

50BF CB failure

50G instantaneous grounding over current

50N the neutral instantaneous over current

50P phase instantaneous over current

50SG sensitive grounding instantaneous over current (measurement in the fifth CT ) .

50ISG isolated instantaneous over current (measurement in the fifth CT ) .

51G grounding over current ((measurement in the fourth CT )

51N the neutral delay over current

51P delay over current with phase voltage resistant

51SG sensitive grounding delay over current (measurement in the fifth CT ) .

59N the neutral overvoltage

59P phase overvoltage

59X auxiliary overvoltage

67P phase direction

67N the neutral direction


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67G the grounding direction

67SG the sensitive grounding direction

79 auto reclosing (with four reclosing)

810 over frequency

81U under frequency

81R frequency change rate

I2/I1 broken line

VTFF VT CB failure

GE T60 protection code

21G Ground distance

51N Neutral time overcurrent

21P Phase distance

51P Phase time overcurrent

24 Volts per hertz

59N Neutral overvoltage

25 Synchrocheck (optional)

59P Phase overvoltage

27P Phase undervoltage

59X Auxiliary overvoltage

27X Auxiliary undervoltage

67N Neutral directional overcurrent

49 Thermal overload (RTD)

67P Phase directional overcurrent

50/87 Instantaneous differential overcurrent

68 Power swing blocking

50BF Breaker failure

78 Out-of-step tripping


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50G Ground instantaneous overcurrent

81O Over frequency

50N Neutral instantaneous overcurrent

81U under frequency

50P Phase instantaneous overcurrent

87G Restricted ground fault

51G Ground time overcurrent

87T Transformer differential


Operation Procedure of 500kv Subtation (HTOM-E-01)

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Transcript of Operation Procedure of 500kv Subtation (HTOM-E-01)