Three Vector Complete Model Predictive Control for Three-Phase Grid-Connected Inverters with LCL Filter

In the traditional model predictive control(T-MPC), only inverter side current of LCL inverter is treated as a control target. Grid side current is controlled indirectly by controlling the inverter side current directly. The control performance of the algorithm can be further improved. In this paper, a complete model predictive control algorithm(C-MPC) which take the grid side current as control target directly is proposed. The equivalent mathematical model and the equivalent circuit model are established based on active damping of capacitive current proportional feedback, then system predictive control model is established by the equivalent mathematical model and the circuit model. In order to make the output current track the directive current accurately at the next moment, the output voltage vector needed at this moment is calculated by the predictive control model. Finally, the required voltage vector is reproduced through space vector modulation(SVM). The simulation results and experimental measurements verify the developed control schemes and show high quality of grid side current (low THDi value).