Low THD modulation strategy for matrix & multi-level matrix converter based on modified DVM

Matrix converter is an array of controlled bidirectional semi-conductor switches that allows direct ac-ac conversion without an intermediate dc link. Considering of its output performance is strictly related to the modulation strategy adopted to control the switching states, the study of modulation improvement attracts more concerns than before in these days. In this paper, normally used modulation methods are discussed at first and then a low THD modulation strategy for a three-phase to three-phase matrix converter is presented. Multi-level matrix topology can operate at high-voltage, large output condition, with other advantages such as, low device voltage switching step, low switching loss, better harmonics characteristics and so on. This modulation strategy, based on voltage & current space-vector notation will be extended to five-level matrix converter in this paper, which lead to a complete solution of the problem and providing a low input current harmony. Simulations results are presented to validate the theoretical findings.