the respective phase is discharged and the return of the phase-to-ground voltage (after the fault has been
cleared) will charge the phase.
Charging the bank causes inrush currents in the respective phases. To avoid overfunction in case of sensitive
threshold settings, the stages using compensated unbalanced values are blocked by setting I
unbal.,comp.
to 0 A.
These stages are:
•
Counter stage
•
I> stage, if set to operate with compensated unbalanced values
The blocking (
I
unbal.,comp.
set to 0 A) lasts for 250 ms after energizing detection. Afterwards, the calculated
I
unbal.,comp.
is processed again.
Energizing detection takes place by monitoring the phases currents I
c
flowing into the bank. If all three phase
currents exceed the threshold Current Thresh.CB Open, energizing is detected.
Logic for Counting Faulty C-Elements
This part of the General functionality is only important if counter stages are used.
[locntEF1ph-070714-01, 3, en_US]
Figure 7-23
Counting Faulty C-Elements
Capacitor Bank Protection
7.5 Current-Unbalance Protection for Capacitors, 1-Phase
1006 SIPROTEC 5, Overcurrent Protection, Manual
C53000-G5040-C017-8, Edition 07.2017
To Next Page
Loading...
