Commutation technique for high-frequency link cycloconverter based on state-machine control

A technique for commutating the load current of a high-frequency link, pulse-width modulated cycloconverter is presented. As the load current makes a sign transition, switch operation becomes critical to avoid commutation failure. Previous techniques required either dead time or the use of large inductors to limit shoot-through current, thereby compromising performance and efficiency. The technique presented here identifies the switching sequence that is necessary to allow load current to commutate naturally without distortion. The switching sequence is managed with a state machine.