OVERVOLTAGE DURING SINGLE LINE FAULT
OVERVOLTAGE DURING SINGLE LINE FAULT
(OP)
Hi, I would like to know the cause of the overvoltage in non-faulted phases during a single line fault of a three phase system. What interaction in the generator or system impedance causes this?
Regards.
Regards.






RE: OVERVOLTAGE DURING SINGLE LINE FAULT
If a bolted fault occurs on one phase of a distribution feeder, the voltage across the fault is essentially zero, but the voltage at the substation is still pretty close to the normal line to neutral voltage.
The path of fault current is from the source, along the phase conductor, through the fault, and back to the source through the neutral/earth return path.
If the line voltage is 7.2 kv, and the phase conductor has 2 times the impedance of the earth/neutral return path, then the voltage from neutral to remote earth at the fault location is about 2.4 kv. This results in an increase of the line to neutral voltage for the unfaulted phases near the fault location.
RE: OVERVOLTAGE DURING SINGLE LINE FAULT
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RE: OVERVOLTAGE DURING SINGLE LINE FAULT
Regards.