Abstract
This paper proposes a high-performance nonlinear control strategy for transient voltage regulation in residential DC microgrids comprising photovoltaic (PV) and battery energy storage systems. A novel non-singular integral terminal sliding mode control with a rapid reaching law (NITSMC-RRL) is designed to tackle the challenges of low inertia, intermittent renewable generation, and bidirectional battery dynamics. The proposed controller introduces a dynamic fractional-order sliding surface and an exponential reaching mechanism to ensure fast convergence, improved robustness, and minimized chattering. Detailed mathematical modeling is performed for a dualconverter architecture integrating a PV-side boost and a batteryside bidirectional buck-boost converter. The control objectives include indirect voltage regulation and coordinated power flow. The effectiveness of the NITSMC-RRL controller is validated through MATLAB/Simulink simulations under varying load and solar conditions. Comparative results with existing nonlinear controllers including backstepping (BS), conventional sliding mode control (SMC), and double integral SMC (DISMC)—demonstrate superior dynamic performance, achieving the lowest overshoot