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345 TRANSFORMER PROTECTION SYSTEM – INSTRUCTION MANUAL
S2 SYSTEM SETUP
CHAPTER 6: SETPOINTS
The following table shows the linear combination of phases of a transformer winding that
achieves the phase shift and zero sequence removal for typical values of
Φ
comp
,
where:
I
A
[w]
= uncompensated winding ‘
w
’ phase A current
I
A
p[w]
= phase and zero sequence compensated winding ‘
w
’ phase A current.
Table 2: Grounding
D/z180°
1
DELTA (gnd 1/
2)
180° lag
D/z240°
1
DELTA (gnd 1/
2)
240° lag
2
ZIG-ZAG (gnd
2/3) 180° lag
0°
2
ZIG-ZAG (gnd
2/3) 240° lag
0°
D/z300°
1
DELTA (gnd 1/
2)
300° lag
3W External
Correction
1
WYE
0°
2
ZIG-ZAG (gnd
2/3) 300° lag
0°
23
WYE 0°
0°
WYE 0°
0°
Transformer
Type
Wdg. Connection
Voltage
Phasors
Phase
Shift
(
Φ
comp
)
Transformer
Type
Wdg. Connection
Voltage
Phasors
Phase
Shift
(
Φ
comp
)
Φ
COMP
[W]
GROUNDING[W] = "NOT WITHIN ZONE"
GROUNDING[W] = "WITHIN ZONE"
0°
30° lag
60° lag
90° lag