Design and optimization of solar photovoltaic microgrids with adaptive storage control for residential standalone systems

Direct Current (DC) microgrids are increasingly vital for integrating solar Photovoltaic (PV) systems into off-grid residential energy networks. This paper proposes a design methodology for standalone solar PV DC microgrids, focusing on Battery Energy Storage System (BESS) optimization and adaptive power management. The system architecture includes PV arrays with Maximum Power Point Tracking (MPPT) via a perturbation and observation algorithm, a bidirectional converter-linked BESS for DC bus voltage stabilization, and control strategies for transitioning between three battery operational modes: charge (State of Charge, SOC < High Threshold, SOCH), discharge (SOC > Low Threshold, SOCL), and idle (SOC > SOCH). A load distribution analysis informs BESS sizing for small households, balancing energy reliability and battery longevity. MATLAB/Simulink simulations and experimental validation demonstrate the system’s ability to maintain stable DC bus voltage, regulate SOC within defined thresholds, and minimize power losses under variable solar irradiance and load conditions, as evidenced by solar irradiance, DC voltage, SOC, and power profiles. This work provides a practical framework for deploying solar-powered DC microgrids in remote residential applications.