One-step commutation in voltage source inverters using pulse wire sensor based current sign detection

The dead-time effect, known as one of the basic problems in dc/ac and ac/ac power conversion, has been investigated over a long period. Varying methods based on the elimination, respectively the reduction of the dead-time effect were proposed over the last years. The main idea, beside the reduction of the semiconductor switching times, is to compensate the impact by adding the averaged dead-time error-voltage to the reference voltage. A more feasible approach is based on the knowledge of the according phase current polarity, whereas only those semiconductors are active switched, which are able to conduct the current in the actual direction. The resulting commutation strategy, known as one-step commutation, promises appreciable improvements concerning the quality of current and voltage waveforms. Beside conventional current measurement methods, a novel robust current sign detection approach, based on pulse wire sensors is presented in this paper. A first implementation of the measuring strategy is demonstrated, taking a common voltage source inverter, controlled by a standard space vector modulation and an one-step commutation algorithm in a simulation environment.