Multistep Model Predictive Control of Grid-Connected Inverter

The research on grid-connected inverters (GCI) is gaining momentum as more and more focus is given to clean energy sources like solar photovoltaic (PV) and wind energy. Conventional GCI uses the proportional-integral (PI) controller in conjunction with the sinusoidal pulse width modulation (SPWM) technique for pumping power to the grid. Model predictive control (MPC) is becoming more relevant in the field of power electronics. Conventional MPC uses a single prediction horizon or single step. This paper proposes the estimation of the optimization criterion for more than one prediction horizon, termed a multistep MPC. The multistep MPC is an extension of the basic MPC. The MATLAB/Simulink simulations of the proposed multistep MPC and the conventional single step MPC are presented in this paper. The total harmonic distortion (THD) values are compared between the conventional MPC and multistep MPC for varied operating conditions. The settling time of the controllers as well as the deviations in the cost function are compared. The simulation results indicate a better performance of the multistep MPC in comparison with a conventional single horizon MPC.