A modified single phase inverter topology with active common mode voltage cancellation

This paper addresses the problem of common mode EMI reduction in single phase PWM inverters by means of active cancellation. A topological modification which balances the switching pattern of the inverter is made. Common mode voltage, which results chiefly from unbalanced switching is thus significantly attenuated. This attenuation translates into a substantial reduction in the size and cost of passive filtering components needed to comply with conducted EMI standards. The principles of operation and performance of the proposed topology are discussed in this paper.