Application of Modified Model Prediction to Three-Phase Cascade Systems

Contrary to the traditional three-level single-phase grid connection, model predictive control (MPC) in the field of multi-level three-phase grid connection has the problems of large number of levels and long rolling calculation time. To overcome these problems, this paper proposes an improved model predictive control strategy. By reducing the number of alternative voltage vectors in the rolling optimization through the candidate voltage vector proximity optimization strategy, the grid connection rate of the system is improved. At the same time, the one-beat delay problem of the system is reduced by the extrapolation method, and the harmonic content of the system is reduced. In order to verify the effectiveness of the proposed method, the corresponding model is built in the MATLAB/Simulink platform and simulation experiments are carried out, and the experimental results verify that the new method reduces the operation time of the system compared with the traditional model prediction method, and at the same time reduces the harmonic content of the system.