Single-switch galvanically isolated quasi-Z-source DC-DC converter

A novel galvanically isolated quasi-Z-source DC-DC converter with a single switch is presented. It is derived from the conventional single-switch nonisolated quasi-Z-source DC-DC converter. The new topology is within the transformer based class of the galvanically isolated impedance-source DC-DC converters, while existing topologies are solely within the coupled inductor based class. This simple solution features low cost, high efficiency and reliability that suits low power or low-voltage applications. Theoretical predictions were verified with simulation in PSIM and experimentally with a 200 W prototype. The topology is further improved using the combined energy transfer principle.