ABB RELION REX640, Техническое руководство, Страница: 967 / 1960

blocked when the ratio between residual current of the parallel line and protected
lines exceeds the
Fact EF current Bal configuration setting.
The parallel line compensation functionality is only used with single
phase-to-earth faults. Parallel line compensation is not used if multiple
phases are included into fault (more than one single earth fault releases).
Parallel lines are mutually coupled
Z<
IN2
IN1
l
d
X
R
Figure 539: Operation principle of parallel line compensation functionality
The operation time delay is defined with the
Gnd operate Dl Znx (x = 1...5) setting.
The timer can be disabled with the
Gnd Op Dl mode Znx = "False" setting. This
blocks the
OPERATE_Zx
(x = 1...5) output of the phase-to-earth measuring elements.
Phase-to-phase impedance measuring elements
The phase-to-phase distance protection is suitable as a basic protection function
against two-phase short circuit faults in various networks, regardless of the
treatment of the neutral point. The short circuit fault protection is enabled with
the
Op Mod PP loops Znx (x = 1...5) = "True" setting.
The reach of the phase-to-phase measuring elements is based on the loop
impedance
(Equation 268)
1MRS759142 F Protection functions
REX640
Technical Manual
967