Composite Predictive Current Tracking Control for LCL-Filtered Grid-Connected Inverter With Switching Harmonics and Model Uncertainties

This paper presents a composite predictive controller for the three phase current controlled voltage source inverter to improve the current tracking performance under switching harmonics as well as model uncertainties. The presence of the LCL filter resonance complicates the development of the control strategy, particularly when the coupling between the harmonic disturbance and grid wave disturbance is considered. To address the aforementioned challenge, a disturbance observer is proposed to compensate harmonic disturbance and a compensate predictive control law is designed to achieve closed-loop stability in the presence of model uncertainties. The parameters of the composite controller are carefully selected to ensure anti-disturbance capability and overall stability of the closed-loop system. Simulation results show that the composite controller can achieve accurate current tracking and improved power quality under heterogeneous disturbances.