10 voltage restrained overcurrent accuracy, 10 voltage restrained overcurrent accuracy -16 – GE 489 User Manual
Page 228
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
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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=