Tapped inductor filter-assisted soft-switching PWM DC-DC power converter with high frequency transformer link for automotive AC power supply

This paper presents a novel voltage source full-bridge type soft-switching phase-shift PWM controlled DC-DC power converter with a high frequency transformer link, which can operate under ZVS transition of leading bridge leg and ZCS transition of lagging bridge leg. This power converter can be used as power conditioner for small-scale solar photovoltaic cell and fuel cell power generation systems and isolated step-up DC-DC power converter for automotive AC power supply. The full-bridge circuit topology with a high frequency step-up transformer makes possible to apply low voltage high performance MOSFETs in order to achieve high efficiency processing of the DC-DC power conversion. The tapped inductor filter including a freewheeling diode is implemented in the output stage of the proposed soft-switching DC-DC power converter to perform soft-switching phase-shift PWM high frequency operation for wide load variation ranges. Moreover, in the proposed DC-DC power converter circuit, the circulating currents are effectively minimized without adding active auxiliary quasi-resonant snubber circuit with power switching devices. The practical effectiveness of the proposed soft-switching DC-DC power converter is verified on the basis of experimental setup.