High-frequency AC-AC converter using 3-in-1 IBPMs and adaptive commutation

Most recently reported AC-AC power converters that are based on modern semiconductor device technology use discrete devices and are rated below 2-3 hp. This paper reports a new design approach using integrated bi-directional power modules (IBPM) and a newly developed 3-in-1 IBPM at a medium power level. As a systematic optimization, a new modular phase-bank design is further proposed to reduce the circuit parasitic inductance, minimize the power connection terminals of the multiple phase converter, and simplify the AC bus structure and wiring. This approach substantially benefits the compactness and cost effectiveness for future AC-AC power converters and regenerative AC drives. An adaptive sequence commutation method is developed to improve the safety and efficiency of the power circuit commutation at high alternating load current. Experimental results of a power converter prototype that operates over 0-400 Hz verify the new concepts and design