Negative Sequence Current - GE G30 Instruction Manual

5.6 GROUPED ELEMENTS
EXAMPLE 5: INTERNAL LOW-CURRENT, HIGH-LOAD SINGLE-LINE-TO-GROUND FAULT WITH NO FEED FROM
THE GROUND
Given the following inputs: IA = 1.10 pu ∠0°, IB = 1.0 pu ∠–120°, IC = 1.0 pu ∠120°, and IG = 0.0 pu ∠0°
The relay calculates the following values:
I_0 = 0.033 pu ∠0°, I_2 = 0.033 pu ∠0°, and I_1 = 1.033 pu ∠0°
Igd = abs(3 × 0.0333 + 0.0) = 0.10 pu, IR0 = abs(3 × 0.033 – (0.0)) = 0.10 pu, IR2 = 3 × 0.033 = 0.10 pu,
IR1 = 1.033 / 8 = 0.1292 pu, and Igr = 0.1292 pu
Despite very low fault current level the differential current is above 75% of the restraining current.
EXAMPLE 6: INTERNAL HIGH-CURRENT SINGLE-LINE-TO-GROUND FAULT WITH NO FEED FROM THE GROUND
Given the following inputs: IA = 10 pu ∠0°, IB = 0 pu, IC = 0 pu, and IG = 0 pu
The relay calculates the following values:
I_0 = 3.3 pu ∠0°, I_2 = 3.3 pu ∠0°, and I_1 = 3.3 pu ∠0°
Igd = abs(3 × 3.3 + 0.0) = 10 pu, IR0 = abs(3 × 3.3 – (0.0)) = 10 pu, IR2 = 3 × 3.3 = 10 pu, IR1 = 3 × (3.33 – 3.33) = 0
pu, and Igr = 10 pu
The differential current is 100% of the restraining current.
a) NEGATIVE SEQUENCE DIRECTIONAL OVERCURRENT (ANSI 67Q, IEC PDEF/PTOC)
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PATH: SETTINGS GROUPED ELEMENTS
5
 NEG SEQ DIR OC1
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5-182
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SETTING GROUP 1(6)
NEG SEQ DIR OC1
FUNCTION: Disabled
NEG SEQ DIR OC1
MESSAGE
SOURCE: SRC 1
NEG SEQ DIR OC1
MESSAGE
OFFSET: 0.00 Ω
NEG SEQ DIR OC1
MESSAGE
TYPE: Neg Sequence
NEG SEQ DIR OC1 POS-
MESSAGE
SEQ RESTRAINT: 0.063
NEG SEQ DIR OC1 FWD
MESSAGE
ECA: 75° Lag
NEG SEQ DIR OC1 FWD
MESSAGE
LIMIT ANGLE: 90°
NEG SEQ DIR OC1 FWD
MESSAGE
PICKUP:
NEG SEQ DIR OC1 REV
MESSAGE
LIMIT ANGLE: 90°
NEG SEQ DIR OC1 REV
MESSAGE
PICKUP:
NEG SEQ DIR OC1 BLK:
MESSAGE
Off
NEG SEQ DIR OC1
MESSAGE
TARGET: Self-reset
G30 Generator Protection System

5.6.7 NEGATIVE SEQUENCE CURRENT

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NEGATIVE SEQUENCE CURRENT
Range: Disabled, Enabled
Range: SRC 1, SRC 2, SRC 3, SRC 4
Range: 0.00 to 250.00 ohms in steps of 0.01
Range: Neg Sequence, Zero Sequence
Range: 0.000 to 0.500 in steps of 0.001
Range: 0 to 90° Lag in steps of 1
Range: 40 to 90° in steps of 1
Range: 0.015 to 30.000 pu in steps of 0.001
0.050 pu
Range: 40 to 90° in steps of 1
Range: 0.015 to 30.000 pu in steps of 0.001
0.050 pu
Range: FlexLogic operand
Range: Self-reset, Latched, Disabled
5 SETTINGS
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NEG SEQ DIR OC1(2)
GE Multilin