Voltage Restrained Overcurrent Accuracy - GE 489 Instruction Manual

7.3 ADDITIONAL FUNCTIONAL TESTS
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
S2 SYSTEM SETUP
S2 SYSTEM SETUP
S2 SYSTEM SETUP
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
S5 CURRENT ELEMENTS
2. The trip time for the extremely inverse ANSI curve is given as:
Time to Trip
where: M =
O/C CURVE MULTIPLIER
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:
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
7
CURRENT/VOLTAGE (5 A UNIT)
CURRENT
Ian = 5 A∠0°
Ibn = 5 A∠120° lag
Icn = 5 A∠240° lag
Ian = 6 A∠0°
Ibn = 6 A∠120° lag
Icn = 6 A∠240° lag
Ian = 10 A∠0°
Ibn = 10 A∠120° lag
Icn = 10 A∠240° lag
Ian = 10 A∠0°
Ibn = 10 A∠120° lag
Icn = 10 A∠240° lag
Ian = 10 A∠0°
Ibn = 10 A∠120° lag
Icn = 10 A∠240° lag
activated; Not Activated
7-16
GEN. PARAMETERS GENERATOR RATED MVA:
GEN. PARAMETERS GENERATOR VOLTAGE PHASE-PHASE:
VOLTAGE SENSING VT CONNECTION TYPE:
VOLTAGE SENSING VOLTAGE TRANSFORMER RATIO:
OVERCURRENT ALARM
OVERCURRENT ALARM
OVERCURRENT ALARM
OVERCURRENT ALARM
PHASE OVERCURRENT
PHASE OVERCURRENT
PHASE OVERCURRENT
PHASE OVERCURRENT
PHASE OVERCURRENT
PHASE OVERCURRENT
⎛
B
⎜
A ------------------------------
+
M × ⎜
I
=
------------------- - C
⎜
〈 〉 ×
K
⎝
setpoint, I = input current, I
phase-to-phase voltage
K ----------------------------------------------------------------------------- -
=
rated phase-to-phase voltage
VOLTAGE EXPECTED OBSERVED
Vab = 120 V∠0° lag
Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
Vab = 120 V∠0°
Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
Vab = 120 V∠0°
Vbc = 120 V∠120° lag
Vca = 120 V∠240° lag
Vab = 100 V∠0°
Vbc = 100 V∠120° lag
Vca = 100 V∠240° lag
Vab = 60 V∠0°
Vbc = 60 V∠120° lag
Vca = 60 V∠240° lag
489 Generator Management Relay

7.3.10 VOLTAGE RESTRAINED OVERCURRENT ACCURACY

"100 MVA"
"Open Delta"
"100:1"
"Unlatched"
OVERCURRENT ALARM:
"1.10 x FLA"
O/C ALARM LEVEL:
OVERCURRENT ALARM DELAY:
"On"
O/C ALARM EVENTS:
PHASE OVERCURRENT TRIP:
ENABLE VOLTAGE RESTRAINT:
"1.5 x CT"
PHASE O/C PICKUP:
"ANSI Extremely Inv."
CURVE SHAPE:
O/C CURVE MULTIPLIER:
"Instantaneous"
O/C CURVE RESET:
D
-------------------------------------- - -------------------------------------- -
+ +
2
⎛ I ⎞ ⎛
------------------- - C ------------------- - C
–
–
⎝ ⎠ ⎝
I 〈 〉 〈 〉
×
K I K
p
p
=
PHASE O/C PICKUP
p
A5 EVENT RECORD
ALARM
DELAY EXPECTED OBSERVED EXPECTED OBSERVED
N/A
7 TESTING
"12000"
"2 s"
"Latched"
"Yes"
"2.00"
⎞
E
⎟
⎟
3
I ⎞
⎟
–
⎠
×
I
⎠
p
setpoint
.
TRIP TRIP DELAY
N/A
N/A
11.8 sec.
6.6 sec.
1.7 sec.
(EQ 7.8)
(EQ 7.9)
N/A
N/A
GE Multilin