Hybrid proportional-integral model predictive control strategy of modular multilevel converter

摘要

Existing control strategies of modular multilevel converter (MMC) have many drawbacks, such as need of several parameter controllers, complex parameter tuning and huge computational burden. This paper proposes a novel control method based on the hybrid architecture of proportional integral (PI) control and model predictive control (MPC). The PI controller is used as external controllers to control the ac-side power and current, while the MPC controller is used to control the internal features of the MMC, i.e. suppressing the circulating current and balancing the capacitor voltages. The proposed hybrid method takes both advantages of PI and MPC strategies, which lightens the computational burden and improves dynamic performance and steady-state accuracy. The validity of the proposed method is verified by the simulation results of a 11-level MMC system using Matlab/Simulink.