In this paper, the topology and working principle of Modular Multilevel Matrix Converter are studied, and the modeling is analyzed. This paper also puts forward the control strategy of MMMC under unbalanced working conditions, and according to the power flow law between bridge arms and the influence of low frequency circulation, puts forward the power compensation strategy of open-loop bridge arms. In this paper, a double-sequence software phase-locked loop based on second-order generalized integrator is used to separate positive and negative sequence voltage. In particular, the influence of negative sequence components in three-phase system asymmetry is studied, and a closed-loop real-time control strategy of capacitor voltage balance between bridge arms is proposed and verified by simulation model.

capacitance voltage balance control,differential-common mode decoupling,modular multilevel matrix converter,power compensation of bridge arm