Transformer Differential Protection - ABB Relion Technical Manual

1MRK 502 048-UUS A
Section 6
6.1
6.1.1
Technical manual
Differential protection

Transformer differential protection

Functionality
Transformer differential protection, three-winding T3WPDIF (87T) is provided with
internal CT ratio matching and phase shift compensation. In addition, zero sequence
elimination is also provided.
The function can be provided with -phase sets of current inputs. All current inputs are
provided with percentage bias restraint features, making the IED suitable for two- or
three-winding transformer arrangements.
Three-winding applications
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152
xx05000052_ansi.vsd
ANSI05000052 V1 EN
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xx05000049_ansi.vsd
ANSI05000049 V1 EN
Figure 29: CT group arrangement
for differential
protection and other
protections
The available settings of this function allow the REG650 to cover various differential
protection applications such as power transformers and auto-transformers with or without
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Section 6
Differential protection
85