Performance analysis of secondary phase shift ZVS DC-DC converter for high voltage application

A Soft-switching DC/DC converter with secondary phase shift control strategy is proposed in this paper. Zero-voltage-switching (ZVS) performance is achieved for all power devices, including the four primary MOSFETs, two secondary MOSFETs and diodes in a wide load range. The circulating current in the freewheeling stage is effectively suppressed to minimize the conduction losses. In addition, the voltage stress on the primary switches is only half of the input voltage by employing the three-level structure. The converter can work in both buck and boost modes to achieve wide input voltage range operation. The operation principle is analyzed and the experimental results are given with a 1kW 100kHz prototype to verify the effectiveness of the proposed converter.