A Comparative Study of the Control Type ZVT PWM Dual Switch Forward Converters: Analysis, Summary and Topology Extensions

In this paper, the general operation principles for the existing control type ZVT PWM dual switch forward converters which possess the same conversion ration are reviewed and their advantages and drawbacks are discussed in detail. Then the control type ZVS techniques of active-clamp and resonant reset are extended to the other dual switch forward converters by whether employing the input for resetting the transformer or not and a family of control type ZVT dual switch forward converters is derived and summarized detailedly. In the same way, the new families of control type ZVT PWM flyback and forward-flyback converters are brought forward. A new and improved control type ZVT PWM dual switch forward converter is proposed and its experimental results confirm the superior performance over the others in the same family.