Transformer Differential Protection, Three Winding T3Wpdif (87T) - ABB Relion Technical Manual

Section 6
Differential protection
6.1.2
6.1.2.1
86
load tap changer as well as for shunt reactors including local feeders within the station. An
adaptive stabilizing feature is included to avoid misoperations during for heavy through-
faults.
Harmonic restraint is included for inrush and overexcitation currents respectively, cross-
blocking is also available. Adaptive harmonic restraint is also included for system
recovery inrush and CT saturation during external faults. A high set unrestrained
differential current protection element is included for a very high speed tripping at a high
internal fault currents.
Included is an innovative sensitive differential protection element based on the theory of
symmetrical components. This element offers the best possible coverage of power
transformer windings turn to turn faults.
Transformer differential protection, three winding T3WPDIF
(87T)
Identification
Function description
Transformer differential protection,
three-winding
IEC 61850 IEC 60617
identification identification
T3WPDIF
3Id/I
SYMBOL-BB V1 EN
1MRK 502 048-UUS A
ANSI/IEEE C37.2
device number
87T
Technical manual