Family of zero current zero voltage transition PWM converters

A new auxiliary circuit is introduced for buck, buck-boost, forward and flyback converters. This auxiliary circuit provides zero current, zero voltage switching condition for the main switch while providing zero current switching condition for the auxiliary switch and diodes. In this converter family, there is no additional voltage and current stress on the main switch. The proposed auxiliary circuit is applied to a buck converter and the resulting ZCZVT PWM buck converter is analysed and its operating modes are presented. A simple design method for auxiliary circuit is discussed. The experimental results of a 175 W ZCZVT buck converter operating at 100 KHz are presented. Other converter topologies with the proposed auxiliary circuit are also introduced.