Implementation of Voltage-Based Commutation in Space-Vector-Modulated Matrix Converter

A novel voltage-based commutation (VBC) strategy without explicit input-voltage measurement is proposed in this paper. By properly selecting the width of the critical intervals, the two-step uncritical commutation and four-step critical commutation approaches are utilized to realize safe VBC. The general switching patterns of space-vector modulation (SVM) are analyzed, and the four-step critical commutations are avoided by using four selected SVM switching patterns; thus, all the commutations in the matrix converter can be achieved by two-step VBC. In order to prevent the commutation processes from being interrupted, the triple-zero-vector switching pattern and the single-zero-vector switching pattern are utilized by selecting an appropriate commutation time and the output-voltage/current distortion is minimized. Prototype experiments have been carried out to show the validity of the control strategies.