Figure 54: P643 Used To Protect An Autotransformer With Unloaded Delta Winding - GE P642 Technical Manual

Chapter 6 - Transformer Differential Protection
1200 :5
HV
A
B
C
V03117

Figure 54: P643 used to protect an autotransformer with unloaded delta winding

Set the following parameters in the SYSTEM CONFIG column:
Setting in GROUP 1 SYSTEM CONFIG
Winding Config
Winding Type
HV CT Terminals
LV CT Terminals
TV CT Terminals
Ref Power S
Ref Vector Group
HV Connection
HV Grounding
HV Nominal
HV Rating
% Reactance
LV Vector Group
LV Connection
LV Grounding
LV Nominal
LV rating
128
175 /175 /30 MVA
230 /115 /13.8 kV
YNynd1
+5% / -15%
19 taps
Protected
zone
Phase & amplitude
Correction
+
Zero sequence filtering
Phase & amplitude
Correction
+
Zero sequence filtering
1200 :5
B B
B B
Zero sequence filtering
B B
B
B
B
D D D
HV+LV+TV
Auto
001
100
010
175.00 MVA
0
Y-Wye
Ungrounded
230.0 kV
175.00 MVA
10.00%
0
Y-Wye
Ungrounded
230.00 kV
175.00 MVA
1200 :5
LV
a
b
c
Phase & amplitude
Correction
+
P643
Value
P64x-TM-EN-1.3
P64x