A full bridge ZCS PWM converter for high voltage and high power applications

Abstract

This paper presents the detailed analysis of a full bridge zero current switched (FB-ZCS) PWM converter that is suitable for high-voltage and high-power DC applications. It exhibits excellent ability to incorporate parasitic parameters, zero current turn-off characteristics for all active switches and ZVS operation for all diodes on the high voltage side. Based on the features of high-voltage power supplies, the converter utilizes parasitic components, particularly for the high-voltage transformer, and employs fixed frequency phase-shift control to implement soft-switching commutations. Steady state analysis of the converter is presented and major features of the converter are discussed. Finally, a small signal model based on the averaging method is created and the simulated results for typical traveling wave tube (TWT) load are given.