New modulation method for matrix converters

This paper presents a new modulation method for matrix converters based on the indirect modulation model. During the switching period, the proposed modulation method uses a combination of only one active vector and a zero vector in the inversion stage to achieve minimum flux error, whereas in the rectification stage, a single current vector is selected according to the angle error of the input current vector. This reduces the number of switching states in the switching period, which improves the accuracy of generating the reference output voltage vector, especially in the low-modulation-index range. In addition, closed-loop control of the input current vector is achieved. The input currents are not measured but are estimated by applying inverse transformation to the measured output currents using the matrix associated with the chosen active switching state.