A Model-Free Current Prediction Control with Runge-Kutta Algorithm for Grid-Connected Inverter

The conventional model predictive control (MPC) strategy produce current errors when the parameters of the inverter mismatch, which increases the Total Harmonic Distortion of grid current. To solve this problem, an improved method based on Runge-Kutta algorithm (RKA) is proposed. On the basis of the mathematical model of grid- connected inverter, current error of parameters mismatch of conventional MPC is analyzed. Moreover, Lagrange interpolation is performed to achieve the predictive current instead of the slope parameters of RKA, because the uncertain model with detailed parameters affects the prediction accuracy. Finally, simulation results verify the accuracy and effectiveness of the improved RKA approach.