Single-phase AC/AC converter based on quasi-Z-source topology

This paper deals with a new family of quasi-Z-source converters applying to AC/AC power conversion called single-phase quasi-Z-source AC/AC converter (qZSAC). The proposed qZSAC inherits all the advantages of the traditional single-phase Z-source AC/AC converter (ZSAC), which can realize buck-boost, reversing or maintaining phase angle. In addition, the proposed qZSAC has the unique features; namely that the input voltage and output voltage is sharing the same ground; the operation is in continuous current mode (CCM). Compared to the conventional ZSAC, the proposed qZSAC has a lower harmonic distortion input current and a higher efficiency. The proposed qZSAC can control to shape the input current to be sinusoidal and in phase with the input voltage. The operating principles of the proposed qZSAC are described, and a circuit analysis is provided. Simulation results are shown in comparison to that of the conventional SZAC. Experimentation is implemented to verify the operational concept.