Mitigation of the adverse effects of PWM inverter through active filter technique

Mitigation of the adverse effects of PWM inverter through active filter technique is discussed in this paper. A PWM inverter fed ac motor drive system capable of suppressing all the adverse effects of PWM inverter based on active cancellation method is developed. An active EMI filter proposed for this system is characterized by sophisticated connection of two small separate filters, which they can mitigate common mode voltages produced by PWM inverter and can suppress leakage current. As a result small active filter with ability of reducing of all the adverse effects is approached. Whole system is modeled and simulated based on SABER simulator. Simulations are verified by experimental results, which show the reduction characteristics of the shaft voltage, bearing current, common mode current, and leakage current.