Novel zero-voltage and zero-current-switching (ZVZCS) full bridge PWM converter using a simple auxiliary circuit

A novel zero voltage and zero current switching (ZVZCS) full bridge (FB) PWM power converter is presented to simplify the circuits of the previously presented ZVSCS power converters. A simple auxiliary circuit which consists of one small capacitor and two small diodes is added in the secondary to provide ZVZCS conditions to primary switches as well as to clamp secondary rectifier voltage. The additional clamp circuit for the secondary rectifier is not necessary. The auxiliary circuit includes neither lossy components nor additional active switches which makes the proposed power converter efficient and cost effective. The principle of operation, features and design considerations are illustrated and verified on a 2.5 kW, 100 kHz IGBT-based experimental circuit.