A New Three-Phase AC-AC Z-source Converter

Abstract

Z-source converters have been developed as a new type of converter besides the other two kinds of traditional converters: voltage-source and current-source converters. Z-source converter has many inherent advantages and is suitable for many applications such as fuel cell system or motor drive because of its single stage structure. Present research works are mostly focused on using Z-source network as a dc-link. For ac/ac conversion, a diode-rectifier front end is needed and the Z-source network will be employed on the dc-link. In this paper, a new three-phase ac-ac Z-source converter is proposed to perform ac/ac conversion directly. Compared to the traditional ac-ac converter, the new ac/ac converter has the same number of devices. Analysis and simulation for this three-phase ac/ac Z-source converter are presented. A 1 kW prototype was built and the experimental results verify the analysis.