Analysis of the Overmodulation Strategy for Two-stage Matrix Converter

Aim to the low voltage transfer ratio problem of the conventional modulation method,a modulation method to enhance voltage transfer ratio of dual stage matrix converter is proposed without changing the topology.The proposed control method is divided into two control stages.Conventional current space vector modulation(SVM)is used for rectifier stage.In inverter stage,a two-level control,linear modulation level and over-modulation level,is used according to different required voltage transfer ratio.The over-modulation level is combined with two over-modulation sections,over-modulation section I and over-modulation section II,both of which are implemented by different inverter stage modulation methods.Over-modula-tion is theoretically analyzed.Simulation and experimental results demonstrate that the output fundamental voltage can be accurately controlled with small total harmonic distortion and good input/output current quality.