Function Block; Functionality; Analog Channel Configuration - ABB RELION REX640 Technical Manual

Section 4
Protection functions
4.3.2.2
4.3.2.3
4.3.2.4
592

Function block

GUID-6F9B958C-EFD9-490D-BC42-7ADC2C161951 V1 EN
Figure 327: Function block

Functionality

The stabilized and instantaneous differential protection for two-winding transformers
function TR2PTDF is designed to protect two-winding transformers and generator-
transformer blocks. TR2PTDF includes low biased and high instantaneous stages.
The biased low stage provides a fast clearance of faults while remaining stable with
high currents passing through the protected zone increasing errors on current
measuring. The second harmonic restraint, together with the 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 over-excitation.
The instantaneous high stage provides a very fast clearance of severe faults with a high
differential current regardless of their harmonics.
The setting characteristic can be set more sensitive with the aid of tap changer position
compensation. The correction of transformation ratio due to the changes in tap
position is done automatically based on the tap changer status information.

Analog channel configuration

TR2PTDF has two analog group inputs which must be properly configured.
Table 580: Analog inputs
Input
I3P1
I3P2
See the preprocessing function blocks in this document for the
possible signal sources.
Improper analog channel configuration causes a validation error if the analog
channels are not completely configured or they do not match with certain settings. For
troubleshooting, check the contents of this chapter and also the preprocessing blocks
Description
Three-phase currents
Three-phase currents
1MRS759142 C
REX640
Technical Manual