Optimized double ZVS-PWM active-clamping forward converter with inputs connected in series and parallel

This paper presents an isolated DC-DC converter with reduced conduction losses based on two ZVS-PWM active-clamping forward converters. In the proposed converter the inputs can be connected in series or parallel depending on the bus voltage application. To reduce rms value of the current and improve voltage and current division on the devices, the commutation inductors were coupled with adequate coupling coefficient. The converters present soft switching features from no-load to full-load condition. Theoretical analysis and experimental results taken from a 3 kW laboratory prototype are presented.