Research on Improved Four-step Commutation Strategy of Matrix Converter Based on Two Line Voltage Synthesis

The commutation process of matrix converter is more complicated compared with traditional AC-DC-AC converter due to having no natural free-wheeling paths, so the commutation problem is one of the main reasons for hindering practical applications. In this paper, the mechanisms involved in the commutation process are firstly described and then several methods to optimize the commutation process are proposed based on two line voltage synthesis, including exchanging switching sequences and adopting variable commutation time. The reliability is increased and waveform quality is enhanced after improvement. Finally, experiment device based on dSPACE is designed and experiment results demonstrate the correctness and availability of the methods presented in this paper.