A Family of ZVS-PWM Active-Clamping DC-to-DC Converters: Synthesis, Analysis, Design, and Experimentation

This paper presents a technique to generate a complete family of two-switch pulsewidth-modulated (PWM) with active clamping dc/dc converters, featuring soft commutation of the semiconductors at zero-voltage (ZVS). The main purpose of this technique is to integrate these converters under a same theoretical principle to derive the topologies in a comprehensive form and generate new circuits. All the converters have the advantage of soft commutation (ZVS) with minimum switch voltage stress due to the clamping action. Besides operating at constant frequency and with reduced commutation losses, these converters have output characteristics similar to the PWM hardswitching counterpart, which means that there is no circulating reactive energy that would cause large conduction losses. Principle of operation, theoretical analysis, simulation and experimental results of one particular converter taken as an example, are provided in this paper.