Soft switching of IGBTs in lagging lag of ZVT phase shift DC/DC converter

The additional effort to achieve zero voltage transition (ZVT) in the lagging leg of frequently used ZVT phase shift full bridge converter can be avoided by designing the converter with `high speed' trench fieldstop IGBTs. Thanks to their reduced turn-off but at the same time low turn-on losses, the lost of ZVT in the lagging leg is not anymore critical to converter's efficiency. Moreover, it can be beneficial due to their improved `conduction to switching loss' ratio. Based on that conclusion, a simple method to maximize their efficiency by minimizing the resonant inductance is proposed.