Predictive Control for Power Quality Improvement and Compensation of Unbalanced Behavior and Harmonics via Smart Converters

This paper addresses the challenging issues of harmonics and unbalanced behavior in future power grids with a high penetration of renewable energy sources, particularly in weak grid environments. It focuses on the harmonic compensation capabilities of power electronic converter interfaced distributed generators (DGs). While voltage-controlled DG converters have been extensively studied for voltage harmonic compensation, limited attention has been given to current-controlled mode (CCM) DGs, which are commonly used in renewable energy generators and energy storage systems. To address this gap, the paper proposes a novel continuous control set model predictive current controller (MPC) for harmonic and unbalanced compensation. The proposed control strategies offer several advantages, including fast control response, absence of steady-state error, the ability to enforce hard constraints on input and output variables, robustness, and adaptability. Experimental tests were conducted at the Smart Converter Lab, PowerLabDK, Technical University of Denmark to validate the proposed approach.