A Single-Phase Z-Source AC–AC Converter With Continuous Input Current and Without Commutation Issue

In this article, a single-phase Z-source ac–ac converter with continuous input current and without commutation issue is proposed. The proposed converter has the ability to provide boost in-phase and buck-boost out-of-phase modes. This operation is achieved using four switches, with only one high-frequency switch being switched in each half cycle of the input voltage. In this converter, the commutation problem has been inherently solved. As a result, the converter is protected from voltage and current spikes on the switches without requiring snubber circuits or safe commutation methods. Also, a simple switching and control pattern is implemented in the proposed converter. By studying the switching device power index and comparing it with other converters, it can be claimed that the proposed converter is cost-effective. The operating principles of the proposed converter in different modes are examined in detail. Eventually, the experimental results of a 70 V rms /50 Hz laboratory prototype are presented to confirm the validity of the theoretical relationships and the correctness of the proposed converter.