Grounding of generator neutral:
Grounding of generator neutral:
(OP)
Grounding of generator neutral:
Generator: 1 MW; 3 phase; 600 V is connected to grid through interface transformer: 1.5 MVA; 27.6 kV star solid gnd/600 V star solid gnd and exports power to grid.
How the generator neutral should be grounded? a) Solid; b)Low impedance; or c) High impedance. If grounded through high imprdance what will restrict the over-voltages if generator islands?
Generator: 1 MW; 3 phase; 600 V is connected to grid through interface transformer: 1.5 MVA; 27.6 kV star solid gnd/600 V star solid gnd and exports power to grid.
How the generator neutral should be grounded? a) Solid; b)Low impedance; or c) High impedance. If grounded through high imprdance what will restrict the over-voltages if generator islands?






RE: Grounding of generator neutral:
RE: Grounding of generator neutral:
RE: Grounding of generator neutral:
If the generator is grounded through high impedance and the interface transformer is star/star solidly grounded at both HV and LV, then after openening of utility breaker for utility ground faults, the overvoltages on healthy phases are unavoidable. The magnitude of the overvoltage will be maximum if there is full neutral shift. Utility is say 3 phase 4 wire. There are 3 phase and single phase load connected in utility distribution system. Loads will moderate the overvoltages.
What would be the ratio of load to generation to keep the overvoltages within acceptable limits?
RE: Grounding of generator neutral: