Control strategy for a Standalone PV System with Battery-Supercapacitor Hybrid Energy Storage Under Cloudy Days

Abstract

Fluctuations in solar irradiance under cloudy conditions pose a significant challenge to the reliability of photovoltaic (PV) systems. This study investigates hybrid energy storage systems (HESS), which combine the high energy capacity of batteries with the high-power density of supercapacitors, as a solution for standalone PV installations. The study adopts a structured approach, beginning with a theoretical foundation on PV and energy storage technologies, followed by the development of mathematical models for system components. These models account for environmental factors and incorporate maximum power point tracking (MPPT) techniques. Extensive simulations assess passive and semi-active HESS topologies under varying weather conditions, employing optimized control strategies to manage power flow, reduce battery stress, minimize unnecessary cycling, and extend battery lifespan. The results demonstrate that a well-designed hybrid storage system significantly enhances the dynamic performance and reliability of PV systems during solar fluctuations while improving the longevity of the storage components. This work contributes to the development of intelligent energy management strategies, which are essential for resilient and autonomous renewable energy systems in the transition to clean energy.