This paper analyzes the influences of shaftvoltage absorbing circuit and brush touching resistance on the performance of generator rotor earth fault protection.
In the three-phase inverter-fed motor drives, the switching devices'PWM waves generate shaftvoltage and bearing current, and these make the motor's life shorter.
The voltage between the system and generator must be small enough to ensure minor current in the armature winding of generator, avoiding the impact to the coupling shaft.