Advances in Control Strategies and Battery Management for Stand-Alone Photovoltaic Systems: A Comprehensive Review

Abstract

With rapid changes in the move toward renewable energy, stand-alone PV systems are considered a critical solution for rural electrification, energy independence, and sustainable development. These systems face several challenges, such as variations in solar irradiance, battery aging, transient load variations, and lack of adequate reactive power support. Recent developments have focused on improving the system reliability and efficiency through methods such as advanced control strategies, battery energy storage systems (BESS), and intelligent power management. The review brings together contributions from 2019 to 2025, drawing attention to improvements in MPPT algorithms, hybrid storage integration, predictive and adaptive controllers, and AI-based solutions. Special focus is placed on transient load handling, with methods such as fractional-order controllers, model predictive control, reinforcement learning, and hybrid optimization techniques attaining superior performance in terms of stability and ride-through capability. Battery management is exposed as a fundamental factor in improving state-of-charge estimation, mitigating cycling stress, and integrating supercapacitors for dynamic response enhancement. The consideration of reactive power is also treated in the review, emphasizing inverter design and battery conversion control for voltage stability support. Further development is shown in experimental validation, modeling of long-term degradation, and the question of scalability for near-market deployment. Keywords identify key gaps and outline future directions for highly reliable, efficient, and sage stand-alone PV systems fitting into the global renewable energy agenda.