Common-mode EMI suppression in a unipolar PWM inverter using genetic-based gating signals tuning

This paper proposes a genetic-based gating signals tuning capable of suppressing common-mode electromagnetic interference (CM EMI) existed in a unipolar PWM inverter. Though the PWM inverter using a unipolar PWM switching pattern has low switching losses and voltage stress across a load, the CM EMI may occur and cause high output-voltage harmonics. To reduce the CM EMI, we use a genetic algorithm to adjust inverter´s gating signals optimally. With the proposed approach, a closed-loop unipolar PWM inverter yields output-voltage of low total harmonic distortion (THD). Experimental results show the effectiveness of the proposed approach.