Full-Range Non-Resonant PWM Zero-Voltage-Switching Power Converters With Minimized Inductor Current Ripple

Abstract

Soft-switching techniques can greatly reduce the switching loss, thus improving the efficiency, power density, and reliability of power converters. Focusing on the non-resonant pulsewidth modulation (PWM) converters, this article proposes a novel approach to realize zero-voltage-switching (ZVS) with constant frequency in the full operation range while minimizing the current ripple. First, the basic quadrilateral current modulation unit (QCMU) is proposed, where an inductor is spanned across the midpoint of two half-bridge legs, so that the inductor current is shaped as quadrilateral with its minimum value constant. Based on that, a family of full-range non-resonant PWM ZVS converters, including dc-dc, dc-ac, and ac-dc converters, is generated. Then, the optimal operating mode and control scheme based on the combined PWM and phase-shift control for the proposed ZVS converters are presented. Experimental results of dc-dc converter, and simulation results of dc-ac inverter and ac-dc rectifier as an extension, are provided to verify the effectiveness of the proposed non-resonant PWM ZVS converters.