Resistor healthy
state se�ng
Switch on
delay 1
Time on 1
Switch on
delay 2
Time on 2
Switch off
delay 1
Time off 1
Switch off
delay 2
Time
”Off”
EARTH_FAULT
Resistor control sequence during
earth-fault
Repeat part
Repeat part
”On”
Figure 928: Resistor control sequence
When the earth-fault indication becomes inactive, any active single sequence or
repeat sequence is cancelled, and the resistor is switched back to its initial state.
The resistor control sequence contains a repeat part which can be repeated after
the whole sequence is executed once. The number of repetitions can be selected
with
Resistor repeats
setting. Additionally, the pause between the consecutive
repeats can be selected with
Resistor pause
setting. If the resistor status is the
opposite to the
Resistor healthy state
when the earth-fault recovers, the resistor is
restored to healthy state at latest after one second from the last resistor change. If
the resistor already is in its healthy state when the earth-fault recovers, the status
remains.
It is also possible to manually trigger the resistor control sequence with
ST_RESIS_SEQ binary input.
9.11.6.7 Blocking
The BLK_AUTO input blocks the automatic operation of the function. PASANCR's
automatic operation is blocked internally if the ASC is disconnected at the
substation, that is, COIL_STS signal is low. The BLK_MANUAL input blocks the
manual control of the coil. The BLK_RESISTOR input disconnects the parallel
resistor and blocks its switching on, for example, due to resistor overheating.
9.11.7 Application
PASANCR is a numerical automatic controller for arc suppression coil (Petersen
coil) and the parallel resistor. It can be applied to compensated networks
where a switched parallel resistor is optionally connected in parallel with the arc-
Control functions
1MRS759142 F
1744 REX640
Technical Manual
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