An Investigation of Methods to Improve Input/Output Current Waveforms in Matrix Converters

Abstract

The matrix converter is a three phase AC-to-AC direct converter without any energy storage requirement such as DC link capacitors. However, the matrix converter has some practical problems such as the necessity of the bi-directional power devices, necessity of special commutation sequence, and complexity of the control method. Thus, there are no practical systems in which the matrix converters are used. In this paper, the control strategy for matrix converters with basic configuration is investigated to realize the practical matrix converters. First of all, the necessity of the phase detector for the input voltage and the output current sensor is pointed out from the viewpoint of realization of the basic operation. With these sensors required in the basic configuration, the instantaneous control of the output current is realized. It is also pointed out that the three phase switching is effective to improve the input current waveforms. Some methods for implementation of the three phase switching are proposed. The effectiveness of the proposed control methods is confirmed by some experimental results employing a test system.