Operation Principle - ABB REL650 series Technical Manual

Section 6
Impedance protection
Table 57: PPLPHIZ Non group settings (basic)
Name Values (Range)
GlobalBaseSel 1 - 6
6.6.6
6.6.6.1
172
Unit Step
- 1

Operation principle

Operation principle
Phase preference logic PPLPHIZ has 10 operation modes, which can be set by the
parameter OperMode. The different modes and their explanation are shown in table
below. The difference between cyclic and acyclic operation can be explained by the
following example. Assume a A fault on one line and a C fault on another line. For
OperMode = 1231c the line with C fault will be tripped (C before A) while for OperMode
= 123a the line with A 1 fault will be tripped (A before C).
Table 58: Operation modes for Phase preference logic
OperMode Description
No filter No filter, phase-to-phase measuring loops are not blocked during single phase-to-
ground faults. Tripping is allowed without any particular phase preference at cross-
country faults
No pref No preference, trip is blocked during single phase-to-ground faults, trip is allowed
without any particular phase preference at cross-country fault
1231 c Cyclic 1231c; A before B before C before C
1321 c Cyclic 1321c; A before C before B before A
123 a Acyclic 123a; A before B beforeC
132 a Acyclic 132a;A before C beforeB
213 a Acyclic 213a; B before A before C
231 a Acyclic 231a; B before C beforeA
312 a Acyclic 312a; C before B beforeA
321 a Acyclic 321a; C before B before A
The function can be divided into two parts; one labeled voltage and current discrimination
and the second one labeled phase preference evaluation, see figure 81.
The aim with the voltage and current discrimination part is to discriminate faulty phases
and to determine if there is a cross-country fault. If cross-country fault is detected, an
internal signal "Detected cross-country fault" is created and sent to the phase preference
part to be used in the evaluation process for determining the condition for trip.
Default Description
1 Selection of one of the Global Base Value
groups
1MRK 506 335-UUS A
58
Technical manual