A single-stage zero-voltage zero-current switched full-bridge DC power supply with extended load power range

A single-stage power factor corrected PWM converter with extended load power range is presented. The topology is based on a zero-voltage zero-current switched full-bridge (ZVZCS-FB) inverter. Steady state analysis of the topology shows that by operating the LC load filter in discontinuous mode, the DC link voltage remains bounded and independent of the load level. Therefore, the load power range can be further expanded, including the no-load operating condition. The analysis also shows that the extension of the load power range is achieved without any penalty in (a) the input power factor (due to the input current waveshaping feature), (b) the converter efficiency (due to ZVZCS and the single-stage features), and (c) the load voltage quality (due to the high bandwidth of the phase loop). Simulated and experimental results are included to show the feasibility of the proposed scheme