A bidirectional three-phase push-pull converter with dual asymmetrical PWM method

This paper proposes a new bidirectional three-phase push-pull converter that has the simplest structure and achieves ZVS of switches. The proposed dual asymmetrical PWM (DAPWM) technique offers not only power flow control or output voltage control but reduced circulating current by matching the primary voltage with the secondary voltage referred to the primary. A bidirectional mode change is easy to implement since switching patterns for both forward and reverse operations are identical and the power flow is determined by the difference in the two duty cycles. Experimental results from a 5kW prototype are provided to validate the proposed concept.