Soft-Switching DC/DC Converter With a Full ZVS Range and Reduced Output Filter for High-Voltage Applications

A new soft-switching dc/dc converter, which can solve the drawbacks of existing phase-shifted full-bridge converters such as narrow zero-voltage-switching (ZVS) range, large circulating current, large duty-cycle loss, and a large output filter in high-voltage applications, is proposed in this paper. The proposed converter is composed of two symmetric half-bridge inverters that are placed in parallel on the primary side and are driven in a phase-shifting manner to regulate the output voltage. At the rectifier stage, two full-bridge rectifiers sharing two low-current-rating diodes are employed. This structure allows the proposed converter to have the advantages of a full ZVS range, no problems related to duty-cycle loss, no circulating current, and a significantly reduced output filter. In this paper, the circuit configuration, operation principle, and relevant analysis results of the proposed converters are presented. Experimental results on a prototype converter realized with the specification of 80-in plasma display panel sustain power module (320-385 V_dc input, 205 V_dc/5 A output) validate the theoretical analysis.