400kv busbar protection
TRANSCRIPT
SETTING RECOMMENDATION APPLN 2012For M/s. HVPNL LTD. 400KV BUSBAR PROTECTIONS
CONFIDENTIALThe information contained in this
document is not to be communicated either directly or
indirectly to any person not indirectly to any person not authorised to receive it.
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
Page 1 of 6
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.
Page 2 of 6
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:
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.
Page 3 of 6
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
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.
Page 4 of 6
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
Blocking latched, Alarms latched, self reset, Alarms& no block, Alarms SR & no block
Blocking latched, Alarms latched, self reset, Alarms& no block, Alarms SR & no block
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
Blocking latched, Alarms latched, self reset, Alarms& no block, Alarms SR & no block
Group1 Busbar Option
DescriptionRange/Options available Adopted
SettingsRemarks
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.
Page 5 of 6
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:
DescriptionRange/Options available Adopted
SettingsRemarks
Group1 CB Fail:
Group1 Supervision:
DescriptionRange/Options available Adopted
SettingsRemarks
DescriptionRange/Options available Adopted
SettingsRemarks
I<, 52a, I< & 52A
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.
Page 6 of 6