An effective method to determine voltage waveform at terminal of induction motor fed by PWM inverter

The PWM inverter drive may cause motor terminal voltage surges and ringing, which impose severe electric stress on interturn insulation of motor windings. This paper presents an effective method to determine the terminal voltage waveform of the motor fed by PWM inverter. In this method, an effective system model is established for simulation. The motor is regarded as a “black box”, so the analysis of inner complicated electromagnetic couplings of motor under high frequency is avoided. The parameters of the motor are based on the test results. The effects of the feeding cable are calculated with multi-conductor transmission line theory. Examples of the PWM fed motor terminal voltage waveform calculated by this method and the comparison of simulation with experimental results are given