Soft switching schemes for multiphase dc/dc converter with six-pulse modulated pulsating output

This paper outlines and compares two switching schemes for an isolated high-frequency multiphase dc/dc converter, which operates as the front-end stage and outputs a six-pulse modulated pulsating-dc voltage for a three-phase rectifier-type high-frequency-link (RHFL) Pulse-width-modulation (PWM) converter. Without adding any additional component, both proposed switching schemes can achieve soft switching for the active switches on the dc/pulsating-dc converter. In conjunction with the back-end pulsating-dc/ac converter operating with patent-filed hybrid modulation scheme, the proposed switching schemes can not only eliminate the intermediate dc filter but also lead to overall less switching loss than other conventional switching schemes.