The linear active disturbance rejection voltage control strategy for outer-loop capacitor of M3C

Modular Multilevel Matrix Converter (M3C) has become a promising AC-AC converter scheme in the Fractional Frequency Transmission System (FFTS) for offshore wind power. As to the traditional M3C control strategy, because the reference value required for the current inner-loop control is the output value of the outer-loop control, the quality of the outer-loop control will directly affect the control effect of the whole system. To further improve the control performance of the system, a new controller is designed to control the outer-loop DC capacitor voltage based on Linear Active Disturbance Rejection Control (LADRC), which can track the reference value faster and more accurately than the traditional controller without relying on an accurate mathematical model. Finally, the simulation model of M3C-FFTS system is built and the simulation results indicate that the designed controller is effective for its good control performance.