Abstract: The traditional deadbeat current predictive control depends on accurate discrete power grid mathematical model, which leads to steady-state error of the current, especially the system instability when the inductance changes beyond a certain range. There is sampling delay in the all digital control, and the system robustness is poor. An improved deadbeat predictive control method combined with repetitive control is proposed to effectively eliminate the command error and disturbance error of grid connected current and provide high-quality steady-state waveform. Simulation results show that the influence of sampling delay caused by traditional control methods is effectively suppressed. It has the advantages of fast response, high steady-state accuracy and small current distortion rate (THD: Total Harmonic Distortion), and avoids the disadvantages of overshoot and oscillation.

Key words: prediction model current controller; photovoltaic grid connected inverter, deadbeat control, repetitive control