Design and Experimental Implementation of a Robust H∞Control for LCLGrid-connected Converter⁎⁎This work was funded by the European Union’s Horizon 2020 Research and Innovation program(Grant No. 883985, Project Name: POSYTYF https://posytyf-h2020.eu/)

Higher penetration of renewable energy into the electrical grids using grid-connected converters requires robust control schemes to ensure the stable behavior of these converters during disturbances on the grid side. This paper proposes a robust H∞control scheme reinforced by the D-stability technique using linear matrix inequality (LMI)approach for a three-phase two-level grid-connected converter with LCLfilter. The design performance is validated both by simulations and experimental tests. The results indicate that the H∞control provides better response during disturbances in the grid such as variations in the grid voltage and short-circuit faults when compared to that of the conventional vector control scheme. An experimental validation is carried out by implementing the control scheme on an OPAL-RT-based realtime system to control the power injection of a grid-connected converter hardware setup. The experimental results match the simulation results and show the efficient performance of the proposed control scheme in providing the desired active/reactive power.