Calculating Settings For Phase Preference Logic Pplphiz - ABB REL650 Applications Manual

1MRK 506 334-UUS A
3.2.1
Application manual
ended over-head transmission line in a high impedance network
application, except the phase preference logic and sensitive directional
residual overcurrent protection which are used in high impedance
networks.

Calculating settings for phase preference logic PPLPHIZ

The phase preference logic is only to be used if it is allowed to operate the network with
single phase-to-ground fault. In case of a "cross-country fault" as shown in the figure the
fault will be seen as a single phase-to-ground fault for each of the distance protections as
long as both faults are fed from the station. The faults are within zone 1.
Y
ANSI11000118 V1 EN
Figure 33: Cross country fault
The aim of the phase preference function is to release distance protection trip one of the
faulted lines so that the other line can remain in service with the single phase-to-ground
fault.
The phase preference logic will identify the faulted phases on each of the faulted lines by
measurement of the phase-to-ground voltages (setting PU27PN), the phase-to-phase
voltages (setting PU27PP), the residual voltage (setting 3V0PU) and the residual current
out on the protected line (setting Pickup_N).
REL 650
REL 650
Section 3
REL650 setting examples
Phase-ground fault
Phase-ground fault
ANSI11000118_1_en.vsd
83