Conducted EMI and over-voltage investigations in a PWM inverter-fed induction motor drive system

This research deals with the development of a PSpice model for a PWM induction motor drive system that allows prediction of over voltage and conducted EMI in the presence of long feeders.; A detailed model of the IGBT inverter is implemented taking into account the parasitic capacitances and inductances. A lumped parameter model with 64 sections has been used for the cable. The per unit length parameter is computed using software Maxwell 2D extractor that uses finite element method.; An induction motor model suited for high frequency studies is proposed. The parameters of the model can be obtained experimentally from different frequency response tests on the motor. This model in parallel with the DQ model can be used for the study of conducted EMI emissions and over-voltage phenomenon in PWM drive systems.; Simulations have been carried out for different cable lengths, inverter voltage rise times and inverter carrier frequencies to investigate the effects of these on over-voltage at motors terminals and total EMI emissions in the system.; The developed model is also used to investigate the effects of over voltage mitigation filters on conducted EMI emission.; Results obtained from an experimental system are compared with the simulation results.