GE G60

GE Multilin G60 Generator Protection System 5-243
5 SETTINGS 5.6 GROUPED ELEMENTS
5
(EQ 5.40)
Therefore, for faults at a fraction k = 0.15 from the neutral grounding point, we set the operating quantities as follows:
(EQ 5.41)
The 100% stator ground settings are described below.
• 100% STATOR GND STG1 PICKUP: This setting specifies a pickup level for the operating quantity. It may be benefi-
cial to measure the operating quantity under various load conditions for a particular machine in order to optimize this
setting. This can be achieved using the actual values menu of the G60.
• 100% STATOR GND STG1 DELAY: This setting specifies a time delay required to operate after the pickup condition is
established.
• 100% STATOR GND STG1 SUPV: This setting specifies a signal level supervision for the vectorial sum of the third
harmonic at the machine neutral and in the zero-sequence terminal voltage. The setting is entered as a per-unit value
of the terminal voltages. Different settings may be considered for stages 1 and 2 as one of them could be used for
alarm and the other for trip. The safe value of this setting could be established after putting a given machine into ser-
vice and reading the quantity from the relay under
ACTUAL VALUES menu.
Figure 5–129: 100% STATOR GROUND SCHEME LOGIC
V
0
1 k–()E
3
1 k–()E
3
1 k–()E
3
++
3
-------------------------------------------------------------------------------------
30.8510××
3
----------------------------------
8.5 === V
N
V
0
+ 8.5 1.5+ 10==
V
N
V
0
+ 10 pu=
Pickup
V
N
V
N
V
0
+
-----------------------
>
1.5
10
--------
0.15 pu==
Supervision V
N
V
0
+< 10 pu=
SETTING
SETTING
SETTING
SETTING
SETTING
SETTING
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
FLEXLOGIC OPERAND
FLEXLOGIC OPERANDS
FLEXLOGIC OPERANDS
100% STATOR GROUND
FUNCTION:
100% STATOR GND BLK:
STATOR GROUND
SOURCE:
100% STATOR GND STG1
DELAY:
100% STATOR GND STG2
DELAY:
100% STATOR GND STG2
PICKUP:
100% STATOR GND STG1
PICKUP:
100% STATOR GND STG2
SUPV:
100% STATOR GND STG1
SUPV:
V_1 > 0.5 pu
100% STATOR PKP
100% STATOR STG2 OP
100% STATOR DPO
100% STATOR OP
100% STATOR STG1 OP
100% STATOR STG1 DPO
100% STATOR STG2 DPO
Off=0
Enabled=1
830003A6.CDR
RUN
Vaux (3rd harmonic)
V_0 (3rd harmonic)
V_1 (fundamental)
20 ms
20 ms
t
t
PKP
PKP
AND
AND
OR
OR
AND
Vaux
Vaux + V_0
Pickup
<
V_0
&
&
Vaux + V_0
1-Pickup
<
Vaux + V_0
Supv
<
100% STATOR STG2 PKP
100% STATOR STG1 PKP