GE Multilin G650 - Negative Sequence Current

5-60 G650 Generator Protection & Control System GEK-113285A
5.4 PROTECTION ELEMENTS 5 SETTINGS
5
5.4.8 NEGATIVE SEQUENCE CURRENT
The Negative sequence menu incorporates the following elements:
• Negative sequence time overcurrent (51-2)
• Negative sequence instantaneous overcurrent (50-2)
• Generator unbalance (46)
5.4.8.1 NEGATIVE SEQUENCE OVERCURRENT ELEMENT (51-2)
Negative Sequence TOC is an overcurrent protection element that uses the fundamental phasor of the negative sequence
current as input magnitude, calculated from the phase currents. This element can be used for detecting load unbalance in
the system, and for open phase conditions (fallen or broken conductor). The trip can be time delayed by a curve selectable
by setting. The reset can be instantaneous or linear.
Table 5–61: NEGATIVE SEQUENCE TOC ELEMENT SETTINGS
The snapshot event setting enables or disables the snapshot event generation for this element.
5.4.8.2 NEGATIVE SEQUENCE INSTANTANEOUS OVERCURRENT ELEMENT (50-2)
Negative Sequence IOC is an overcurrent protection element that uses the fundamental phasor of the negative sequence
current as input magnitude, calculated from the phase currents. This element can be used for detecting load unbalance in
the system, and for open phase conditions (fallen or broken conductor). The trip time can be selected as instantaneous
or
timed, with the timer selectable between 0.00 and 900 seconds. The element incorporates a reset time selectable between
0 and 900 seconds.
Table 5–62: NEGATIVE SEQUENCE IOC ELEMENT SETTINGS
The snapshot event setting enables or disables the snapshot event generation for this element.
SETPOINT > PROTECTION ELEMENTS > NEGATIVE SEQUENCE CURRENT > NEGATIVE SEQUENCE TOC >
NEGATIVE SEQUENCE TOC 1> NEGATIVE SEQUENCE TOC 2 > NEGATIVE SEQUENCE TOC 3
SETTING DESCRIPTION NAME DEFAULT VALUE STEP RANGE
Function permission Function DISABLED N/A [DISABLED – ENABLED]
Pickup level Pickup Level 1.00 0.01 A [0.05 : 160.00]
Curve shape Curve IEEE Ext Inv N/A [See list of curves]
Time Dial TD Multiplier 1.00 0.01 s [0.00 : 900.00]
Reset type Reset INSTANTANEOUS N/A [INSTANTANEOUS – LINEAR]
Snapshot Event generation Snapshot Events ENABLED N/A [DISABLED – ENABLED]
SETPOINT > PROTECTION ELEMENTS > NEGATIVE SEQUENCE CURRENT > NEGATIVE SEQUENCE IOC >
NEGATIVE SEQUENCE IOC 1> NEGATIVE SEQUENCE IOC 2 > NEGATIVE SEQUENCE IOC 3
SETTING DESCRIPTION NAME DEFAULT VALUE STEP RANGE
Function permission Function DISABLED N/A [DISABLED – ENABLED]
Pickup level Pickup Level 30.00 0.01 A [0.05 : 160.00]
Trip time Trip delay 0.00 s 0.01 s [0.00 : 900.00]
Reset time Reset delay 0.00 s 0.01 s [0.00 : 900.00]
Snapshot Event generation Snapshot Events ENABLED N/A [DISABLED – ENABLED]