400kv Busbar Protection

SETTING RECOMMENDATION APPLN 2012For M/s. HVPNL LTD. 400KV BUSBAR PROTECTIONS

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SETTING CALCULATION FOR SETTING CALCULATION FOR BUSBAR BUSBAR PROTECTION PROTECTION RELAYSRELAYS

400KV BUSBAR 400KV BUSBAR PROTECTIONSPROTECTIONS

CUSTOMER :M/s HVPNL LTD

PROJECT :400/220/66/33KV S/S AT FARIDABAD (NAWADA)

GRID

Prepared By Sudheendra.K

Date 17.08.2012

Approved By Sreenatha Rao. R.S.N.V

Revision Rev.0

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400KV BUSBAR PROTECTION1. SUBSTATION INFORMATION

CTR - Primary of all feeders

CT knee Point for all feeders

Settings and configuration of the P741 Numerical bus bar protection scheme is arrived based on the substation information providedby ALTOM SYSTEMS/HVPNL as detailed below.

CTR - Secondary of all feeders 12000

2000 VCT resistance for all feeders 15 Ohms

Maximum Short circuit levelMaximum loading of 1 bar (ASSUMED)Number of independent bars

During normal operation the differential current in the scheme should be zero or negligible. Any abnormality is detected via a giventhreshold ID>1. This element is using for CT supervision. Recommended setting should be more than 2 % of maximum CT ratio andless than “Minimum Loaded feeder Current”. Recommended setting is 40 A. (NOTE : IF THE SPILL CURRENT IS MORE THAN 90ASHALL BE ADJUSTED AT SITE ACCORDINGLY)

2. Slope k1 setting range is from 0% to 50%. Recommended setting is 0% , as the minimum loading current is very less and CTs are ofsame ratio & similar magnetising characteristics.

Note: All values in CU is for base current of 2000A. 1.ID>1 (from 0.01 to 0.5 A (secondary value))

3000 A 245 A 6 kA 40 kA

6 values have to be entered in MiCOM P741 central unit

Two Main System

100 m sec (assumed 40msec breaker op. time + arcing time) Maximum breaking time of CB

Maximum Load level in a feederMinimum load current in a feeder Minimum Short circuit level (ASSUMED)

2. SETTING CRIETERIA OF MiCOM P741 – CENTRAL UNIT

3000 A

FOR M/S. HVPNL - NAWADA400KV BUSBAR PROTECTION,Rev-0

M/S. ALSTOM T&D INDIA LTD,19/1, G.S.T.ROAD,

PALLAVARAM,CHENNAI - 600043.

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2400 Amp

2400 Amp

5 secs60 secs

A trip is only permitted if this differential current exceeds the set slope of the bias characteristic. Recommended value for normalapplication is 65%.

Recommended setting is 30%.5.ID>2 (from 0.5 to 30 A (secondary value)) as low as possible

The main differential current element of MiCOM P741 will only be able to operate if the differential current reaches a threshold ID>2.In general, this setting will be adjusted above highest normal full load current in order to avoid mal operation even max loaded feederCT fails. Normally recommended setting is more than 110 -180% of max load level. We shall choose ID>2, more than max loadingconsidering (high instantaneous loading) and less than 50% of minimum short circuit level. Recommended setting is 2000*1.2= 2400A

Cz PU errorZx PU error

Alarms LatchedAlarms Latched

4. Slope KCZ setting range is from 0% to 90%, it should be less than Icc min (1 bar) / (((Independent bar - 1) x IloadMax (1 bar)) +Icc min (1 bar)).

ID>1 Alarm Timer Diff Earth Fault

40.00 Amp5.00 sec Disable

Phase Slope k2

3. Slope k2 setting range is from 20% to 90%, and recommendation is 65% , as the CTs are of same ratio & similar magnetizingcharacteristics and to provide stability for through faults.

30.00%Phase Slope kcz

0.00%GROUP 1 CommonPhase Slope k1

Circ flt reset time

PU error timerPU error reset time

60 secsCirc flt block mode

GROUP 1 Diff Phase FaultGROUP 1 CZ Parameters

6.ID>1 Alarm Timer (from 100ms to 600 s) shall be greater than the longest protection time (such as line, over current, etc…)Recommended time delay is 5 secs.GROUP 1 DIFF BUSBAR PROT

ID>2 Current

IDCZ>2 Current GROUP 1 Zone Parameters

65.00%

Block / phase.

GROUP1 Busbar Option:CZ circ flt modeZx circ flt mode

Alarms LatchedAlarms Latched

ID>1 Current

P741 Central unit blocking modes:




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2000 Amp

----------(TO BE ENTERED AT SITE)

2400 Amp

CT & VT RATIOS: For all feeders

Phase CT Sec'y RBPh / RBN

For all feeders

I< (under current) Recommended setting is 20% of CTR. The setting is 400 A.

A re-trip can be applied after a time tBF1/tBF3. Here we are issuing the retrip command after 50ms of main trip.

CBF timer TBF2/tBF4:

15 Ohms

--------(TO BE ENTERED AT SITE) 1 Amp

Phase CT Primary

3.SETTING CRITERIA OF MICOM P743 – PERIPHERAL UNITS

I> Status

Dead Zone setting for all feeders:

Disabled GROUP 1 Internal Trip CB Fail Timer 1 50ms

200.0ms CB Fail Timer 2 GROUP 1 External Trip CB Fail Timer 3

I>DZ Current setting I> DZ time delay 50 m sec

CB Fail:

Knee Voltage Vk RCT Sec'y

NOTE: RBPh/RBn, Vk, Rct & Effective Burden values are very important to detect /confirm the CT Saturation condition.

I<400

When both the local trip & retrip have failed, the countdown continues with a second timer adjusted to have a value of tBF2/tBF4. Recommended setting is “maximum breaking time of CB” + 100 msec. Recommended tBF2 & 4 setting is 200msec.

GROUP 1 CB FAIL Control By I< Current Set for all feeders

Retrip timer TBF1/tBF3:

Eff. Burden Ohm

2000 V

Power Parameters:For all feedersStandard Input British Standard

4. CB Fail Protection: 50 LBB

5. Dead Zone Protection:CB Fail Timer 4

Dead zone tripping is provided to sense the fault in-between CT and breaker when breaker is open. Dead zone setting shall be morethan maximum loading & less than 80 % of the minimum fault current. Time delay of 50 m secs shall be given to avoid mal operationduring arcing period, CB scattering during fault, where CB Open has been realised by PU.

50ms 200.0ms




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Minimum MaximumPhase slope KCZ 0% 90% 30% Check zone slope IDCZ>2 current 50A 30.0kA 2400 Check zone threshold Phase slope K2 20% 90% 65% Main zone slope ID>2 current 50A 30.0kA 2400 Main zone threshold ID>1 current 10A 500A 90A Circuitry fault pickup Phase slope K1 0% 50% 0% Circuitry fault slope

ID>1 Alarm timer 100ms 600 s 5 secs Circuitry fault alarm delay

Minimum Maximum

CZ circ flt mode Alarms latchedResetting mode of CZcircuitry fault

Zx circ flt mode Alarms latchedResetting mode of mainzones circuitry fault

Circuitry t reset 5 s 600 s 60 s Circuitry fault reset time

Circ block mode Blocking /

phaseBlocking modes on circuitryfault

CZ PU Error mode Alarms latchedResetting mode of PUduring CZ error

Zx PU Error mode Alarms latchedResetting mode of PUduring main zone error

PU Error timer 2 s 600 s 5secs Alarm delay of PU errorPU Error reset 5 s 600 s 60secs Reset time of PU error

Minimum Maximum

Phase CT Primary 1A 30.0 kA2000 A for all

feedersCT Primary Rating

Remarks Description

Range/Options available6B. SETTING SUMMARY FOR PHERIPHAL UNIT – P743

Range/Options availableGroup1 DIFF BUSBAR PROT

40%

Adopted Settings

5 secs

Group 1 Io supervision :

CT, VT Ratios:

6A. SETTING SUMMARY FOR CENTRAL UNIT – P741

Blocking latched, Alarms latched, self reset, Alarms& no block, Alarms SR & no block

DescriptionAdopted Settings

Remarks



Internal CT / AD converter of PU can be monitored by comparing the measured 3Io and derived neutral (IN =IR + IY + IB). Error coefficient shall be kept at 40% in order to detect internal CT (PU) failure.

Error factor KCE Alarm delay

Blocking/ phase , 3 phase block


Group1 Busbar Option

DescriptionRange/Options available Adopted

SettingsRemarks




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Phase CT Secondary 1A 5A 1A CT Secondary Rating

RBph/RBN 0.5 10 **Ratio of Phase & neutral CT leads resistance

Standard InputBritish

StandardCT Standard

Knee Voltage Vk 20 V 5000 V2000 V for all

feedersCT Knee point Voltage

RCT Sec 0.1 Ω 50 Ω15 Ohms forall

feedersCT sec resistance

Effective Burden ohm 0.1 Ω 200 Ω ** Effective burden of lead

Minimum MaximumI> DZ Current Set 60 A 4800 A 2400I> DZ Time Delay 0 sec 100 sec 50 msecIN> DZ Current Set Disable

Minimum MaximumControl by I<I< 60 A 1200 A 400CB Fail Timer 1 0 sec 10 sec 50 msecCB Fail Timer 2 0 sec 10 sec 200 msecCB Fail Timer 3 0 sec 10 sec 50 msecCB Fail Timer 4 0 sec 10 sec 200 msec

Minimum MaximumError Factor Kce 1% 100% 40%Alarm Delay Tce 0 sec 10 sec 5 sec

Enable/Disable

British Standard / IEC

Group1 Dead Zone Protection:


SettingsRemarks

Group1 CB Fail:

Group1 Supervision:


SettingsRemarks


SettingsRemarks

I<, 52a, I< & 52A




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400kv Busbar Protection

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