Analysis and modeling of a novel ZVZCS FBPWM converter

A novel zero-voltage and zero-current-switch (ZVZCS) full-bridge PWM converter is presented. There are neither additional active switches nor lossy components in the proposed converter to achieve ZVZCS conditions. Moreover, the ZVZCS conditions are achieved by changing the traditional configuration of ZVS-full-bridge without added control: a simple auxiliary circuit is added in the secondary and the center tap of the transformer's secondary is linked to the auxiliary circuit. The secondary rectifier voltage of the converter is clamped to a relative low level, so additional clamp circuit for the secondary rectifier is not necessary. Using a new improved approach, which concerns the energy input into the secondary rather than the voltage in secondary, a complete small-signal model for the converter is developed through simple calculation. The operation of the proposed converter is analyzed, some important formulas are deduced. The experimental results of a 1.2-KW prototype prove that the novel converter is successful.