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GE Multilin
L60 Line Phase Comparison Relay
9-3
9 APPLICATION OF SETTINGS
9.1 PHASE COMPARISON ELEMENT 87PC
9
Ttr_rst = Tpr Tbreak_adj – Ttr_pkp
where: Tprot_adj is the expected time of main protection operation on the adjacent line,
Tbreak_adj is the operation time of the breaker on the adjacent line,
Ttr_pkp is selected Transient Pickup time.
87PC BLOCK:
The user can define some cases when blocking of the phase comparison scheme is required. This setting will block the trip-
ping function. PLC alarm contacts indicating channel failure are usually assigned for this setting,. especially in blocking
schemes.
87PC CHNL LOSS TRIP WINDOW:
This setting is applicable to the 2TL-BL-DPC-2FL scheme only. The typical setting is 150 ms.
9.1.3 SETTINGS EXAMPLE
Consider settings for a single-circuit 765 kV line, 100 miles length, 50 Ohms primary impedance, 5520 ohms shunt capaci-
tance of the line, maximum expected load of 2000A, CT ratio 2000/5, minimum expected internal 3-phase fault is 8000A.
1.
Mixed signal factor K=0.2
2.
FDL pickup:
I
FDL
= 1.1
×
2000
×
0.2 = 440 A or 440 / 400 = 1.1 A secondary.
The setting is 1.1 / 5 = 0.22 pu.
3.
FDH pickup: I
FDH
= 4/3*I
FDL
+0.375*Icapac = 1.33*440+0.375*80 = 615.2 A or 615.2/400 = 1.54 A secondary; setting is
1.76/5 = 0.31 pu. Where Icapac=765000/(
√
3*5520) = 80 A
4.
Stability angle:
φ
load = 2*arcsin((2000*50*
√
3)/(2*765000)) = 13.0°
φ
capac = arctan(Icapac/I
FDH
) = arctan(80/615.2) = 7.4°
φ
s(deg) = 13.0°+7.4°+10° = 30.4°
Minimum recommended setting 60° (set as default) should be applied.
5.
Check against requirement for trip supervision by distance relay: As minimum internal 3-phase fault is much than twice
the maximum line load current, no distance element is required for be assigned to FD INPUT setting.
2000/5
L60-1
L60-2
765 kV
2000/5
100 mi
∼
∼
Содержание L60
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Страница 24: ...1 14 L60 Line Phase Comparison Relay GE Multilin 1 5 USING THE RELAY 1 GETTING STARTED 1...
Страница 42: ...2 18 L60 Line Phase Comparison Relay GE Multilin 2 2 SPECIFICATIONS 2 PRODUCT DESCRIPTION 2...
Страница 78: ...3 36 L60 Line Phase Comparison Relay GE Multilin 3 3 DIRECT INPUT OUTPUT COMMUNICATIONS 3 HARDWARE 3...
Страница 368: ...8 28 L60 Line Phase Comparison Relay GE Multilin 8 2 SINGLE POLE TRIPPING 8 THEORY OF OPERATION 8...
Страница 470: ...D 10 L60 Line Phase Comparison Relay GE Multilin D 1 PROTOCOL APPENDIXD D...
Страница 482: ...E 12 L60 Line Phase Comparison Relay GE Multilin E 2 DNP POINT LISTS APPENDIXE E...
Страница 498: ...x L60 Line Phase Comparison Relay GE Multilin INDEX Z ZERO SEQUENCE CORE BALANCE 3 9...