GE G60 UR Series, Instruction Manual

Page: 305 / 634

GE Multilin G60 Generator Protection System 5-173
5 SETTINGS 5.6 GROUPED ELEMENTS
5
• GEN UNBAL STG1 K-RESET: This setting defines the linear reset rate of the stage 1 element. It is the maximum reset
time from the threshold of tripping. This feature provides a thermal memory of previous unbalance conditions.
• GEN UNBAL STG2 PICKUP: This setting defines the pickup of the stage 2 element expressed as a percentage of the
nominal current as specified by
GEN UNBAL INOM
setting. The definite time element would normally be used to generate
an alarm to prompt an operator to take some corrective action. The stage 2 element would typically be set at a safe
margin below the stage 1 pickup setting.
• GEN UNBAL STG2 PKP DELAY: This is the minimum operate time of the stage 2 element. This is set to prevent nui-
sance alarms during system faults.
Figure 5–91: GENERATOR UNBALANCE INVERSE TIME CURVES
Figure 5–92: GENERATOR UNBALANCE SCHEME LOGIC
0.1
1
10
100
1000
0.01 0.1 1 10 100
830714A1.CDR
Tmax
K=1 K=4 K=15 K=40 K=100
Tmin
SETTING
SETTING
SETTINGS
SETTING
SETTINGS
SETTING
FLEXLOGIC OPERANDS
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
GEN UNBAL
FUNCTION:
GEN UNBAL
BLOCK:
GEN UNBAL
SOURCE:
GEN UNBAL STG1 PKP
GEN UNBAL STG1 DPO
GEN UNBAL STG1 OP
GEN UNBAL STG2 PKP
GEN UNBAL STG2 DPO
GEN UNBAL STG2 OP
GEN UNBAL PKP
GEN UNBAL OP
Off=0
RUN
RUN
I_2
Enabled=1
Disabled=0
AND
OR
OR
OR
AND
GEN UNBAL
INOM:
GEN UNBAL
STG1 PICKUP:
GEN UNBAL
STG1 K-VALUE:
GEN UNBAL
STG1 TMIN:
GEN UNBAL
STG1 TMAX:
GEN UNBAL
STG1 K-RESET:
GEN UNBAL STG2
PKP DELAY:
GEN UNBAL STG2
PICKUP:
GEN UNBAL INOM:
I_2
t
I_2 > PICKUP x INOM
100
GEN UNBAL DPO
T
PKP
0