Adaptive Sliding Mode Control of a Grid-Forming Inverter for Stable Operation in Renewable Energy Microgrids

Abstract

The increasing integration of renewable energy resources into modern power systems has created significant challenges in maintaining voltage stability, frequency regulation, and overall microgrid reliability due to the intermittent nature of solar and wind generation. This study proposes an Adaptive Sliding Mode Control (ASMC) strategy for a Grid-Forming Inverter (GFMI) to enhance the dynamic performance and stability of renewable energy microgrids under varying operating conditions. A nonlinear mathematical model of the inverter was developed in the synchronous (dq)-reference frame, and an adaptive sliding mode controller was designed to improve voltage tracking accuracy while reducing the chattering effect associated with conventional sliding mode control. The proposed controller was implemented and evaluated in MATLAB/Simulink under several operating scenarios, including sudden load changes, renewable power fluctuations, battery charging and discharging transitions, and islanded microgrid operation. Simulation results demonstrated that the ASMC maintained accurate voltage regulation, rapid transient response, low steady-state error, and excellent disturbance rejection compared with conventional control approaches. The findings confirm that the proposed ASMC-based grid-forming inverter significantly improves microgrid stability, robustness, and power quality, making it a promising control solution for future renewable energy-based smart grids with high penetration of distributed energy resources.