Z-Source AC-AC Converters Solving Commutation Problem

A new family of Z-source AC-AC converters with buck-boost ability are proposed, including four switches single-phase structure and six switches three- phase structure. New commutation strategies for these converters are proposed and safe commutation can be achieved without snubber circuit. Analysis, simulation and experimental results on the voltage-fed Z-source AC- AC converters verified the analysis. These converters have merits such as less conduction and switching loss, less devices, therefore high efficiency and reliability can be achieved.