Novel Hybrid Modulation Schemes Significantly Extending the Reactive Power Control Range of All Matrix Converter Topologies With Low Computational Effort

A novel approach based on indirect modulation, which significantly extends the reactive power control range for three-phase ac-ac matrix converters (MCs; applicable to all matrix topologies) and which is implementable with lowest computational effort, is proposed. This new method denoted as hybrid modulation facilitates the formation of reactive input current also for purely reactive load. The derivation of the modulation schemes, which rely on a decoupling of the output voltage and the reactive input current formation, is described in detail. Furthermore, the operating limits, i.e., the maximum reactive input current that could be formed for the given output voltage amplitude and load current amplitude, are determined. Finally, all theoretical considerations are verified by measurements taken on a 6.5-kW Very Sparse MC.