A Coordinated SOC and SOH Balancing Method for M-BESS Energy Management in Frequency Regulation Considering Economic Benefit and Dispatchability

The growing share of renewable energy resources highlights the need for reliable energy management in frequency regulation. Multi-type battery energy storage system (M-BESS) aggregators are promising resources, yet their heterogeneous costs, capacities, and lifetimes make conventional state-of-charge (SOC) balancing insufficient. This paper develops a coordinated SOC and state-of-health (SOH) balancing method for M-BESS energy management under frequency regulation. An aggregator profit model is first formulated to integrate energy trading benefits and frequency regulation revenues. Then, a dispatchability model is established to capture differences in unit capacity, degradation cost, and operating states, ensuring stable response to frequency regulation signals. Based on these models, a coordinated allocation framework is designed to balance SOC and SOH while improving dispatchability. Case studies with real project data show that the proposed method limits the maximum profit loss ratio to 0.95%, enhances SOH consistency, and improves dispatchability accuracy by more than 10% compared with conventional SOC-based approaches. These results confirm that the method can achieve a practical trade-off between economic benefit, battery health, and reliable participation in frequency regulation markets.