Single-phase transformer based Z-source AC-AC converters

A family of single-phase transformer based Z-source ac-ac converters is proposed in this paper. The proposed converters has the main features which are buck-boost, maintaining, or reversing the phase angle, improved input profiles, continuous input current, shared ground between the input and output, and improved reliability. Moreover, it employs transformers in the impedance network, hence the required voltage gain can be achieved by adjusting the turns ratio. The gain can be tuned by either increasing or decreasing the turns ratio of the transformer depending on the configuration of the Z-source structure. The operation of each converter is presented in detail and simulations are performed to verify the working principles and their benefits.