Improved fuzzy and grey wolf joint control strategy for grid connected hybrid energy storage systems

This paper proposes a joint control strategy that combines an improved fuzzy logic control (FLC) scheme with the Grey Wolf Optimizer (GWO) on the basis of an existing model to address the problems of power fluctuations and energy coordination in a grid connected system composed of wind power, photovoltaic (PV) units, gas generation from waste recovery and an electrochemical battery energy storage system (BESS) modelled in an idealised way. A multi-input FLC is constructed with power deviation and battery state of charge (SOC) as inputs, and three gain coefficients ke, kSOC, and kP that are introduced in the power deviation, SOC and control output channels, respectively, which are optimised by GWO so that battery output power follows the target power trajectory more closely over a 24 hour scheduling horizon. Simulation results indicate that, on a representative day with high renewable output, the improved FLC plus GWO strategy reduces grid interaction while maintaining high local utilization and safe battery SOC. Relative to the original FLC, exported energy magnitude decreases by 15.53 MWh and peak grid connected power by 3.12 MW, mitigating grid side impacts and providing greater regulation margin.