Galvanically isolated quasi-Z-source DC-DC converters with combined energy transfer for renewable energy sources integration

This paper presents a novel class of quasi-Z-source galvanically isolated DC-DC converters intended for the integration of low voltage renewable energy sources into a DC microgrid. These converters combine characteristics of the transformer based and the inductor based impedance-source galvanically isolated DC-DC converters. They feature the continuous input current essential for photovoltaic applications. Two types of the quasi-Z-source based converters are presented within the proposed class: with the full-bridge and the push-pull switching stage. Also, two possible variations of coupling in the impedance-source network are described for both converter types.