Phase Selection With Load Enchroachment, Quadrilateral Characteristic Fdpspdis (21) - ABB REL650 Applications Manual

1MRK 506 334-UUS A
6.2
6.2.1
6.2.2
6.2.3
6.2.3.1
Application manual
Phase selection with load enchroachment, quadrilateral
characteristic FDPSPDIS (21)
Identification
Function description
Phase selection with load
encroachment, quadrilateral
characteristic
Application
The operation of transmission networks today is in many cases close to the stability limit.
The ability to accurately and reliably classify the different types of fault, so that
autoreclosing can be used plays an important role in this matter. The Phase selection with
load encroachment function (FDPSPDIS, 21) is designed to accurately select the proper
fault loop in the distance measuring function depending on the fault type.
The heavy load transfer that is common in many transmission networks may in some cases
be in opposite to the wanted fault resistance coverage. Therefore, the function has a built
in algorithm for load encroachment, which gives the possibility to enlarge the resistive
setting of both the Phase selection with load encroachment and the measuring zones
without interfering with the load.
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.
The extensive output signals from FDPSPDIS (21) give also important information about
faulty phase(s), which can be used for fault analysis.
Setting guidelines
Load encroachment characteristics
The phase selector must at least cover the overreaching zone 2 in order to achieve correct
phase selection for utilizing autoreclosing for faults on the entire line. It is not necessary
to cover all distance protection zones. A safety margin of at least 10% is recommended.
In order to get operation from distance zones (ZQMPDIS, 21), the phase selection outputs
Impedance protection
IEC 61850 IEC 60617
identification identification
FDPSPDIS
Z<phs
SYMBOL-DD V1 EN
Section 6
ANSI/IEEE C37.2
device number
21
139