Investigation and Suppression of the Adverse Effects of PWM Inverter through Passive Filter Technique

A PWM inverter fed AC induction motor drive system capable of suppressing all the adverse effects of PWM inverter is developed in this paper. A passive electromagnetic interference (EMI) filter is proposed, designed, and tested for a 4-kW drive system, is characterized by sophisticated connection of two small passive filters can compensate for common mode voltages produced by PWM inverter and can suppress leakage current. An equivalent common-mode circuit for the drive system equipped with the EMI filter is derived from experimental waveforms along with theoretical discussions verifies that the EMI filter is viable and effective in eliminating all adverse effects of PWM inverter