A Novel Highly Reliable Three-Phase Buck-Boost AC-AC Converter

In this paper, a novel three-phase buck-boost ac-ac converter is proposed. It requires only three inductors and six switches. The proposed converter has no current shoot-through related problems and eliminates the PWM dead times, which results in greatly enhanced system reliability. The proposed converter allow the use of MOSFET without conducting body diode, therefore the reverse recovery issues and related loss of MOSFET body diode can be eliminated. The use of MOSFET in conjunction with external diode reduces the power loss, and the converter can be designed at higher switching frequency to reduce the volume of passive components. A 1 kW hardware prototype of the proposed three-phase buck-boost ac-ac converter is fabricated and tested. The detailed analysis followed by experimental results are provided to prove the novelty of the proposed converter.