An experimental verification and analysis of a single-phase to three-phase matrix converter using PDM control method for high-frequency applications

This paper discusses the PDM (Pulse Density Modulation) control method for a single-phase to three-phase matrix converter (MC) in the high-frequency application. The proposed circuit is used as an interface converter for a wireless power transfer system. This converter can input a several hundred kHz frequency and outputting a low frequency, ie 50 Hz, for commercial power grid. The proposed circuit achieves zero voltage switching (ZVS) operation by using the PDM control method and obtains high efficiency. In this paper, the PDM control strategy is using delta-sigma conversion and improving the PDM pattern generation method based on Space Vector Modulation (SVM). Also, the simulation, experimental and loss analysis results of the proposed system will be demonstrated and discussed. As a result, the total harmonic distortion (THD) of the input current and the output voltage are 84.6 % and 5.4 % respectively. The efficiency of 91.5% is obtained from the prototype circuit. Additionally, the effect of power source side impedance for a high-frequency single-phase-to-three-phase MC is discussed. It is clear that the line-to-line capacitance at the power source side must be kept as small as possible in order to suppress the resonance.