ABB RELION RET670, Applications Manual

Page: 464 / 1016

System studies should determine the settings for the hold timer tH . The purpose of this
timer is, to secure continuous output signal from Power swing detection function
(ZMRPSB, 68) during the power swing, even after the transient impedance leaves
ZMRPSB (68) operating characteristic and is expected to return within a certain time
due to continuous swinging. Consider the minimum possible speed of power swinging
in a particular system.
The tR1 inhibit timer delays the influence of the detected residual current on the inhibit
criteria for ZMRPSB(68). It prevents operation of the function for short transients in
the residual current measured by the IED.
The tR2 inhibit timer disables the output PICKUP signal from ZMRPSB (68) function,
if the measured impedance remains within ZMRPSB (68) operating area for a time
longer than the set
tR2 value. This time delay was usually set to approximately two
seconds in older power-swing devices.
The setting of the tGF timer must cover, with sufficient margin, the opening time of a
circuit breaker and the dead-time of a single-phase autoreclosing together with the
breaker closing time.
8.15 Power swing logic PSLPSCH
SEMOD153597-1 v3
8.15.1 Identification
SEMOD175682-2 v3
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Power swing logic PSLPSCH - -
8.15.2 Application
SEMOD131359-4 v3
Power Swing Logic (PSLPSCH) is a complementary function to Power Swing
Detection (ZMRPSB, 68) function. It enables a reliable fault clearing for different
faults on protected lines during power swings in power systems.
It is a general goal, to secure fast and selective operation of the distance protection
scheme for the faults, which occur on power lines during power swings. It is possible
to distinguish between the following main cases:
Section 8
1MRK 504 163-UUS A
Impedance protection
458 Transformer protection RET670 2.2 ANSI
Application manual