Analysis of three-level full -bridge ZVZCS PWM converter with simple auxiliary circuit

Abstract

This paper proposes a three-level full-bridge ZVZCS converter with ZVS turn on and ZCS turn off conditions using a simple auxiliary circuit on secondary side. The primary current is reset in order to reduce circulating current in transformer and voltage stress and spike voltage of diode bridge rectifier on secondary side. The control strategy uses double phase-shift PWM to control output voltage. Therefore, the lower breakdown voltage of diodes, the smaller LC filter. The simple auxiliary circuit can help to maintain output voltage. Also, The experimental and simulation results from a 100 V/10 A, 60 kHz are also presented, which is used to verify the theoretical analysis. © 2012 IEEE.