An inductorless asymmetrical ZVS full bridge converter for step-up applications with wide input voltage range

This paper proposes an inductorless full-bridge DC-DC converter for step up applications. The proposed converter can achieve ZVS of all switches by utilizing transformer leakage inductance and MOSFET output capacitance. Owing to negligible duty cycle loss and use of voltage doubler, the proposed converter has greatly reduced turn ratio, which makes this voltage-fed converter viable for high step up application. In addition, the proposed converter does not necessitate a clamp circuit at the secondary since the diodes are turned off under ZCS. The diode voltage rating is fixed at the output voltage regardless of input voltage. Further, the transformer VA rating is reduced compared to the conventional converter due to the absence of circulating current. Therefore, the proposed converter is suitable for application with wide input voltage range. Experimental results on a 1kW prototype are provided to validate the proposed concept.