The magnitude of the generator earth-fault current is limited by

• A. controlling field exciter
• B. inserting the stabilizing resistance in series with the relay
• C. inserting suitable resistance in neutral grounding circuit
• D. using higher rating CTs

Answer: (C)

The neutral point of a generator is usually earthed to facilitate protection of the stator winding and associated system.
Earthing also prevents damaging transient overvoltages in the event of an arcing earth fault or ferro resonance.
For HV generators, impedance is usually inserted in the stator earthing connection to limit the magnitude of earth fault current.