Open-Current Vector Based SVM Strategy of Sparse Matrix Converter for Common-Mode Voltage Reduction

The concept of open-current vector for sparse matrix converter (SMC) is put forward along with its application constraints in this paper. Based on the open-current vector, an improved space vector modulation (SVM) strategy is proposed to reduce the peak magnitude of common-mode voltage (CMV) by 42.3% without sacrificing the performance of input and output waveforms and the voltage transfer ratio (VTR). Firstly, the application constraints and common-mode equivalent circuit of the open-current vector in the rectifier stage of the sparse matrix converter are analyzed. After that, in accordance with the principle of minimum switching action and two adjacent active vector synthesis, the improved SVM strategy used a suitable open-current vector instead of the active-current vector in the rectifier stage when the zero-voltage vector is used in the inverter stage, which contributes to CMV reduction. The improved SVM strategy not only reduces the peak magnitude of the CMV, but also ensures that the performance of input and output waveforms and the VTR are the same with those of traditional SVM. Finally, the effectiveness of the improved SVM strategy is verified by simulation and experiments.