A high-frequency transformer isolated soft-switching three-phase AC-to-DC converter with low harmonic distortion

A fixed-frequency, high-frequency transformer isolated, single-stage soft-switching, 3-/spl phi/ AC-to-DC converter with low line current harmonic distortion is proposed. The power converter uses only two switches and uses a simple control circuit without any active current control scheme. Various operating modes of the power converter are presented and analyzed. Based on the analysis, design curves are obtained and an optimum design is given. A design example is presented. Results obtained from SPICE simulation and a 500 W output prototype are given to verify the performance of the proposed converter for varying load as well as line voltage. The power converter maintains low harmonic distortion for the complete line and load variation.