Family of two-switch soft-switched asymmetrical PWM DC/DC converters

Abstract

In this paper, the inter-relationships among two-switch, soft-switched, PWM converters are explored. Starting from a generalized two-switch converter operated under an asymmetrical PWM scheme, the paper first conceptually derives the nonisolated converters-both hard-switched and soft-switched types. Isolated versions with output inductive and capacitive filtering are then introduced. The inclusion of the primary side leakage inductance to aid the ZVS mechanism in the inductive filtering variation is addressed. The operations of the converters are discussed in detail. Results of the DC analysis for all the converters are also given. Finally, comparative evaluation of the different converters is provided. All the converters generally have the advantages of lossless switching, minimum switch voltage stress, fixed frequency operation and minimum component count. Though many of the converters have been described elsewhere, the paper integrates them under a common qualitative and theoretical framework.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>