Optimization Analysis of Frequency Regulation Systems for Thermal Power Units from the Perspective of Lithium-Ion Battery Hybrid Energy Storage

rageTo address issues such as response lag, limited regulation rates, and insufficient low-amplitude command tracking accuracy during thermal power units'' participation in AGC frequency regulation, this study proposes an optimized integrated thermal-storage frequency regulation scheme utilizing lithium-ion batteries and supercapacitors. First, mathematical models are established for thermal power units, lithium-ion batteries, supercapacitors, and bidirectional converters, forming a three-tier control architecture comprising model-based command prediction, fuzzy sliding-mode execution control, and SOC adaptive balancing. Subsequently, rolling optimization achieves coordinated power allocation between thermal units and hybrid energy storage, while fuzzy sliding-mode control enhances converter tracking efficiency and the SOC balancing strategy improves system stability. Simulation results demonstrate that the proposed method significantly reduces frequency regulation response time, improves regulation rate and tracking accuracy, effectively mitigates lithium-ion battery cycle stress, and balances frequency regulation performance with energy storage lifespan.