Four-step Switching Strategy for Bidirectional Switches in Single-phase AC/AC Buck Converter

"Four quadrant commutation" technique is used to solve the switching problems of bidirectional switches. Based on the relative value of voltage or current direction, the switching process between two bidirectional switches is performed in 4 steps, which can achieve the real safe commutation and avoid the faults. This paper discusses the four-step switching strategy in single-phase AC/AC Buck converter; detailed design is provided and the experimental results confirmed the proposed four-step switching strategy.