A Direct Matrix Converter with Space Vector Modulation for Contactless Energy Transfer Systems

Normally, a contactless energy transfer (CET) system contains multiple power transfer stages, which leads to a decreased efficiency factor and higher overall system cost. In this case, the primary side rectifier stage is based on hard switching topologies. This paper proposes a three-phase direct matrix converter controlled with space vector modulation in combination with a delta-sigma modulation on the primary side. Compared to other control strategies, this allows to obtain a sinusoidal mains current and therefore constant input power with a single converter stage. In contrast to other control strategies, which either do not reach a sinusoidal mains current or are not based on zero current switching, this method combines both. The detailed analytical theory of the control strategy is presented and the results are verified with measurements of a prototype system.