Stabilized And Instantaneous Differential Protection For Two- Or Three-Winding Transformers Tr3Ptdf; Identification; Function Block; Functionality - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.3.3
4.3.3.1
4.3.3.2
4.3.3.3
628
Stabilized and instantaneous differential protection for two-
or three-winding transformers TR3PTDF

Identification

Function description
Stabilized and instantaneous differential
protection for two- or three-winding
transformers

Function block

GUID-D556009F-E4CC-4C3F-8EFB-6EB1EC6C5578 V1 EN
Figure 346: Function block

Functionality

The stabilized and instantaneous differential protection for two- or three-winding
transformers function TR3PTDF provides up to three three-phase current sets or
restraints designed for the protection of two-winding or three-winding transformers
and generator-transformer blocks. It is possible to have two three-phase current sets
either on the winding 1 or winding 2 side in case of two-winding transformer
protection. The function includes a biased low stage and an instantaneous high stage.
The biased low stage provides fast fault clearing while remaining stable with the high
currents passing through the protected zone, which increase the errors in current
measuring. The second harmonic restraint, together with waveform-based algorithms,
ensures that the low stage does not operate due to the transformer inrush currents. The
fifth harmonic restraint ensures that the low stage does not operate on apparent
differential current caused by a harmless transformer overexcitation.
The instantaneous high stage provides very fast clearing of severe faults with a high
differential current regardless of their harmonics.
The setting characteristic can be set more sensitive with tap changer position
compensation. The correction of the transformation ratio due to changes in tap
position is done automatically based on the tap changer status information provided to
the function through input.
IEC 61850 IEC 60617
identification identification
TR3PTDF 3dI>3W
1MRS759142 C
ANSI/IEEE C37.2
device number
87T3
REX640
Technical Manual