GE F60 - Negative-Sequence Current

GE Multilin F60 Feeder Protection System 5-201
5 SETTINGS 5.6 GROUPED ELEMENTS
5
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.
5.6.8 NEGATIVE-SEQUENCE CURRENT
a) MAIN MENU
PATH: SETTINGS  GROUPED ELEMENTS  SETTING GROUP 1(6)  NEGATIVE SEQUENCE CURRENT
For additional information on the negative sequence time overcurrent curves, refer to the Inverse Time Overcurrent Curves
section earlier.
 NEGATIVE SEQUENCE
 CURRENT
 NEG SEQ TOC1

See page 5–202.
MESSAGE
 NEG SEQ TOC2

See page 5–202.
MESSAGE
 NEG SEQ IOC1

See page 5–203.
MESSAGE
 NEG SEQ IOC2

See page 5–203.
MESSAGE
 NEG SEQ DIR OC1

See page 5–204.
MESSAGE
 NEG SEQ DIR OC2

See page 5–204.