A review of mitigation methods for overvoltage in long-cable-fed PWM AC drives

The phenomenon of overvoltage at motor terminals in long-cable-fed PWM AC drives poses a severe stress on motor insulation systems. The overvoltage is typically caused by the high change rate of the inverter output voltage (dv/dt) and the surge impedance mismatch between the inverter, connecting power cable and the motor. This paper presents a comparative survey of the existing methods of overvoltage suppression, which includes passive filters at both motor terminals and inverter terminals. The design methodologies, effectiveness, and practical applicability of these passive filters are discussed through computer simulations based on Ansys/Simplorer 9.0, and the promising approaches are recommended for researchers and industrial users.