SVPWM Technique with Varying DC-Link Voltage for Common Mode Voltage Reduction in an Indirect Matrix Converter

This paper discusses a modified space vector technique applied to an indirect matrix converter (IMC) which results in the reduction of common mode voltages and other advanced features. The conventional indirect space vector pulse-width modulation (SVPWM) method of controlling matrix converters involves the usage of two adjacent active vectors and one zero vector for both rectifying and inverting stages of the converter. By suitable selection of space vectors, the rectifying stage of the matrix converter can generate different levels of virtual DC-link voltage. This capability can be exploited for operation of the converter in different ranges of modulation indices for varying machine speeds. This results in lower common mode voltage and improves the harmonic spectrum of the output voltage, without increasing the number of switching transitions as compared to conventional modulation. The effectiveness of the algorithm is substantiated by simulations in MATLAB/Simulink and experiments on a laboratory prototype.