ABB Relion 670 series, Technical Reference Manual

Page: 332 / 1232

6.10 Phase selection, quadrilateral characteristic with
settable angle FRPSPDIS (21)
Function description IEC 61850
identification
IEC 60617
identification
ANSI/IEEE C37.2
device number
Phase selection, quadrilateral
characteristic with settable angle
FRPSPDIS
Z<phs
SYMBOL-DD V1 EN
21
6.10.1 Introduction
The operation of transmission networks today is in many cases close to the stability
limit. Due to environmental considerations, the rate of expansion and reinforcement of
the power system is reduced, for example, difficulties to get permission to build new
power lines. The ability to accurately and reliably classify the different types of fault,
so that single pole tripping and autoreclosing can be used plays an important role in
this matter. Phase selection, quadrilateral characteristic with settable angle FRPSPDIS
(21) is designed to accurately select the proper fault loop in the distance function
dependent on the fault type.
The heavy load transfer that is common in many transmission networks may make
fault resistance coverage difficult to achieve. Therefore, FRPSPDIS (21) has a built-in
algorithm for load encroachment, which gives the possibility to enlarge the resistive
setting of both the phase selection and the measuring zones without interfering with the
load.
The extensive output signals from the phase selection gives also important information
about faulty phase(s) which can be used for fault analysis.
A current-based phase selection is also included. The measuring elements continuously
measure three phase currents and the residual current and, compare them with the set
values.
6.10.2 Principle of operation
The basic impedance algorithm for the operation of the phase selection measuring
elements is the same as for the distance zone measuring function. Phase selection,
quadrilateral characteristic with settable angle (FRPSPDIS, 21) includes six impedance
measuring loops; three intended for phase-to-ground faults, and three intended for phase-
to-phase as well as for three-phase faults.
Section 6
1MRK505222-UUS C
Impedance protection
326
Technical reference manual