Common-mode voltage reduction for three-phase-to-four-leg direct matrix converter with a novel control strategy

Due to the three-phase-to-three-leg direct matrix converter (3 × 3 MC) cannot be achieved with unbalanced load, then the three-phase-to-four-leg direct matrix converter (3 × 4 MC) is introduced. A novel modulation strategy is proposed to ensure the capability of 3 × 4 MC with arbitrary loads, which is development by using fixed voltage vectors and one zero vector. Considering the harm of common-mode voltage (CMV), the switch configurations of the proposed modulation strategy are improved. Selecting the reasonable zero vectors by the subsection partition, which is capable of reducing the CMV to half of the input source voltage produced by the zero vectors, and the ability of 3 × 4 MC with arbitrary load is also realized. The feasibility of the proposed strategy is verified by the accompanying simulation results.