Enhancing Grid-Forming Inverters Operation in Islanded AC Microgrids through PR-Based Sliding Mode Control

This paper introduces a novel control strategy for voltage and frequency ($V / f$) regulation of grid-forming inverters within AC microgrids. Serving as a critical enabling technology for the advancement of future resilient power grids. The proposed control scheme leverages a Proportional-Resonant (PR)-based sliding mode control framework to achieve enhanced active and reactive power sharing, ultimately leading to robust V/f regulation. Traditional PI (proportional-integral) controllers used for $V / f$ regulation in grid-forming inverter networks suffer from two key limitations. The inherent nested-loop control architecture necessitates extensive parameter tuning to achieve optimal performance, a challenge addressed by the proposed approach. Furthermore, conventional $V / f$ control methodologies often exhibit limitations in accurately regulating active and reactive power flow under dynamic load conditions. This deficiency poses a potential risk to the resilient operation of future power systems. This paper proposes a control scheme that simultaneously minimizes tuning complexity and enhances active/reactive power sharing capability for grid-forming inverters within an AC microgrid. A comprehensive analysis is conducted to validate the proposed approach’s effectiveness. The analysis demonstrates the proposed control scheme’s ability to achieve excellent dynamic performance, characterized by minimal power ripple. Furthermore, the analysis confirms the effectiveness of the approach in achieving precise active and reactive power sharing among interconnected inverters. This work contributes to the development of advanced control strategies for AC microgrid applications, paving the way for more resilient and efficient power grid operation.