Design and implementation of a distributed control structure for modular multilevel matrix converter

The modular multilevel matrix converter (M3C) is a direct ac/ac topology that is promising in the medium-voltage high-power application. However, the current M3C mainly adopts the centralized control structure which may hinder its modularity and flexibility. So a distributed control structure and corresponding design principles are proposed to realize the distribution of control tasks and improve the expandability. The input, output and balancing control is based on the double αβ0 transformation, and the real-time current loop is established in the abc coordinate frame in each slave controller independently. Since the distributed control is decoupling in time dimension, the low-cost Controller-Area-Network (CAN) bus is enough to transmit the slow voltage loop data. The effectiveness of the proposed distributed control structure is verified on a laboratory M3C prototype.