ABB RES670 Technical Manual page 189

1MRK 511 408-UUS A
Phasor measurement unit RES670 2.2 ANSI
Technical manual
Reverse
ANSI05000745 V1 EN-US
Figure 52: Directional characteristic of the phase overcurrent protection
The default value of AngleRCA is –55°. The parameter AngleROA gives the angular
distance from AngleRCA to define the directional borders.
A minimum current for the directional phase pickup current signal can be set.
PUMinOpPhSel is the pickup level for the directional evaluation of IA, IB and IC. The
directional signals release the overcurrent measurement in the respective phases if their
current amplitudes are higher than the pickup level (PUMinOpPhSel) and the direction
of the current is according to the set direction of the step.
If no blocking signals are active, the pickup signal will start the timer of the steps. The
time characteristic for each step can be chosen as definite time delay or an inverse time
delay characteristic. A wide range of standardized inverse time delay characteristics is
available. It is also possible to create a tailor made time characteristic.
The possibilities for inverse time characteristics are described in section
characteristics".
RCA
ROA
ROA
Forward
I
dir
Section 8
Current protection
V
ref
en05000745_ansi.vsd
"Inverse
183