An Adaptive Fuzzy Control Strategy to Reduce Battery Current for Optimization Against Rapid Variability in PV Systems

Photovoltaic (PV) power fluctuates rapidly due to cloud cover and similar effects. In emerging PV battery systems, power fluctuations are managed by the batteries, which places a significant burden on battery capacity and reduces their service life. To address this issue, this article proposes a gradient-based adaptive fuzzy control energy management strategy that mitigates variability at the source of PV power and reduces the impact of power fluctuations on battery capacity and current. The adaptive fuzzy control method targets PV power ramp rates, battery state of charge (SoC), and battery current as its control objectives. Given the inherent unpredictability of PV power, the method evaluates battery current and adaptively adjusts its range using backward difference and root mean square propagation (RMSprop) algorithms. Simulation results demonstrate that the proposed strategy achieves a significant improvement over existing methods, reducing battery current and SoC variation by up to 70%. Experimental validation on an integrated PV energy storage multiport platform further confirms its feasibility and effectiveness.