ABB ret650 - Autotransformer Winding, Solidly Earthed

REFPDIF
- 1
I3PW1CT1
I3P
IdN/I
Protected
winding W1
I3PW2CT1
I3P
IdN/I
REFPDIF
- 2
Protected
winding W2
Earthing
transformer
IEC09000110-4-EN.vsd
IEC09000110-4-EN V2 EN-US
Figure 35: Connection of the low impedance Restricted earth-fault function
REFPDIF for a zig-zag earthing transformer
6.2.2.3 Autotransformer winding, solidly earthed
M13048-13 v9
Autotransformers can be protected with the low impedance restricted earth-fault
protection function REFPDIF. The complete transformer will then be protected
including the HV side, the neutral connection and the LV side. The connection of
REFPDIF for this application is shown in figure 36.
1MRK 504 169-UEN A Section 6
Differential protection
Transformer protection RET650 2.2 IEC 95
Application manual