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7-16 489 Generator Management Relay GE Multilin
7.3 ADDITIONAL FUNCTIONAL TESTS 7 TESTING
7
7.3.10 VOLTAGE RESTRAINED OVERCURRENT ACCURACY
Setup the relay as shown in Figure 7–3: Secondary Injection Test Setup #3 on page 7–15.
1. Alter the following setpoints.
S2 SYSTEM SETUP ÖØ GEN. PARAMETERS Ö GENERATOR RATED MVA: "100 MVA"
S2 SYSTEM SETUP ÖØ GEN. PARAMETERS ÖØ GENERATOR VOLTAGE PHASE-PHASE: "12000"
S2 SYSTEM SETUP ÖØ VOLTAGE SENSING Ö VT CONNECTION TYPE: "Open Delta"
S2 SYSTEM SETUP ÖØ VOLTAGE SENSING ÖØ VOLTAGE TRANSFORMER RATIO: "100:1"
S5 CURRENT ELEMENTS Ö OVERCURRENT ALARM Ö OVERCURRENT ALARM: "Unlatched"
S5 CURRENT ELEMENTS Ö OVERCURRENT ALARM ÖØ O/C ALARM LEVEL: "1.10 x FLA"
S5 CURRENT ELEMENTS Ö OVERCURRENT ALARM ÖØ OVERCURRENT ALARM DELAY: "2 s"
S5 CURRENT ELEMENTS Ö OVERCURRENT ALARM ÖØ O/C ALARM EVENTS: "On"
S5 CURRENT ELEMENTS ÖØ PHASE OVERCURRENT Ö PHASE OVERCURRENT TRIP: "Latched"
S5 CURRENT ELEMENTS ÖØ PHASE OVERCURRENT ÖØ ENABLE VOLTAGE RESTRAINT: "Yes"
S5 CURRENT ELEMENTS ÖØ PHASE OVERCURRENT ÖØ PHASE O/C PICKUP: "1.5 x CT"
S5 CURRENT ELEMENTS ÖØ PHASE OVERCURRENT ÖØ CURVE SHAPE: "ANSI Extremely Inv."
S5 CURRENT ELEMENTS ÖØ PHASE OVERCURRENT ÖØ O/C CURVE MULTIPLIER: "2.00"
S5 CURRENT ELEMENTS ÖØ PHASE OVERCURRENT ÖØ O/C CURVE RESET: "Instantaneous"
2. The trip time for the extremely inverse ANSI curve is given as:
(EQ 7.8)
where: M = O/C CURVE MULTIPLIER setpoint, I = input current, I
p
= PHASE O/C PICKUP setpoint
A, B, C, D, E = curve constants; A = 0.0399, B = 0.2294, C = 0.5000, D = 3.0094, E = 0.7222
K = voltage restrained multiplier <optional>
3. The voltage restrained multiplier is calculated as:
(EQ 7.9)
and has a range of 0.1 to 0.9.
4. Using Figure 7–3: Secondary Injection Test Setup #3 on page 7–15, inject current and apply voltage as per the table
below. Verify the alarm/trip elements and view the event records in A5 EVENT RECORD.
CURRENT/VOLTAGE (5 A UNIT) ALARM TRIP TRIP DELAY
CURRENT VOLTAGE
EXPECTED OBSERVED DELAY EXPECTED OBSERVED EXPECTED OBSERVED
Ian = 5 A∠0°
Ibn = 5 A∠120° lag
Icn = 5 A∠240° lag
Vab = 120 V∠0° lag
Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
N/A N/A N/A
Ian = 6 A∠0°
Ibn = 6 A∠120° lag
Icn = 6 A∠240° lag
Vab = 120 V∠0°
Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
N/A N/A
Ian = 10 A∠0°
Ibn = 10 A∠120° lag
Icn = 10 A∠240° lag
Vab = 120 V∠0°
Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
11.8 sec.
Ian = 10 A∠0°
Ibn = 10 A∠120°
lag
Icn = 10 A∠240° lag
Vab = 100 V∠0°
Vbc = 100 V∠120° lag
Vca = 100 V∠240° lag
6.6 sec.
Ian = 10 A∠0°
Ibn = 10 A∠120° lag
Icn = 10 A∠240° lag
Vab = 60 V∠0°
Vbc = 60 V∠120° lag
Vca = 60 V∠240° lag
1.7 sec.
activated; Not Activated
Time to Trip M
A
B
I
K〈〉 I
p
×
-------------------- C–
------------------------------
D
I
K〈〉 I
p
×
-------------------- C–
⎝⎠
⎛⎞
2
-------------------------------------- -
E
I
K〈〉 I
p
×
-------------------- C–
⎝⎠
⎛⎞
3
-------------------------------------- -++ +
⎝⎠
⎜⎟
⎜⎟
⎜⎟
⎛⎞
×=
K
phase-to-phase voltage
rated phase-to-phase voltage
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