Distributed Power Tracking Control of Energy Storage Systems With Aggregated Capacity Estimation

Numerous small-scale energy storage systems (ESSs) are distributed throughout the power system and have the potential to be aggregated for power regulation. In this context, distributed power tracking control with aggregated capacity estimation is proposed for distributed ESSs. The proposed distributed control is free of the measure for total power while achieving accurate total power tracking. In addition, power allocation is performed among ESSs considering their types, SoC levels, and power/energy capacities. To estimate the dispatched power ranges of ESSs, an event-triggered distributed power capacity estimator is proposed with a relatively low communication burden. The power reference for the power tracking control is limited and therefore the reliable operation of the control is ensured. The proposed control and estimator are implemented in a discrete-time fashion and only rely on the sparse communication requirement. A detailed theoretical analysis is conducted to verify the equilibrium and convergence of the proposed approaches. Simulations based on the IEEE 33-bus system demonstrate the effectiveness of the proposed distributed power tracking control and the capacity estimator.