A Robust Method to Improve Stability in Matrix Converters

The last few years witness a high interest in the use of matrix converter technology in AC/AC power conversion. This paper is focusing on its stability issues. It analyzes the instability reason and reveals that the harmonics interaction of its input current and input voltage is the main cause of instability. The matrix converter stability can be improved by decoupling its input current with the input voltage. A modulation strategy is presented that satisfies the idea. The difference of the strategy compared with the traditional one only concerns on the definition of the reference angle for the input current vector. A matrix converter model that takes the switching behavior and effects related with the digital implementations into consideration is developed for evaluation of the strategy. The simulation results show that the proposed strategy can highly improve the matrix converter stability. It is simple in implementation and the algorithm is robust. Experimental results are presented to verify the conclusions.