Galvanically Isolated Quasi-Z-Source DC-DC Converter With a Novel ZVS and ZCS Technique

This paper focuses on the galvanically isolated quasi-Z-source dc-dc converter with a novel zero voltage and zero current switching technique. The unique feature of the impedance network lies in combining the buck-boost operation capability with the short-and open-circuit immunity of transistors; at the same time, it can perform zero voltage and zero current switching on the primary side. The boundary conductionmode of the current in the second inductor of the quasi-Z-source network was used along with snubber capacitors in the two out of four transistors and a special control algorithm to achieve full zero-switching operation of the inverter. Simulation and experimental results prove the discussed ideas. Possible modifications of the algorithm and future applications are also described.