Hello,
Let's say we have transformer. Primary(delta or star) is connected to medium voltage, neutral is isolated. Secondary(star) connected to low voltage, neutral is solidly grounded.
What primary and secondary phasor diagrams would look like in case of 1 phase ground fault in medium voltage...
We have a problem with several pumps.
Pump motor P = 90kW, In=166A, 400V connected through 250A adjustable circuit breaker and ABB PSE170 soft starter.
The problem is that when motor is switched off either circuit breaker or soft starter trips quite frequently.
I suspect that at switch off motor...
I have a question regarding directional earth fault settings calculation in ungrounded system.
Typical system i'm concerned is a small source(wind turbine) connected to MV system through LV(0.4kV or 0.69kV)/MV (10kV or 20kV) voltage transformer. LV side is solidly grounded, MV side is...
