Abstract:
The hybrid energy storage station consists of energy storage units with different types and different performances. To utilize the frequency regulation(FR) performance of each independent energy storage unit effectively, it is urgent to improve the power optimization strategy of the hybrid energy storage station participating in the power grid FR. This paper proposes a power control strategy in which the FR efficiency of energy storage units participating in the grid is taken into account. An efficiency evaluation system that includes three categories of energy storage FR cost, benefit, and performance with six indicators is established. The TOPSIS evaluation method of subjective and objective comprehensive weights based on the analytic hierarchy process and entropy weight method is adopted to evaluate the comprehensive efficiency of each energy storage unit. The efficiency of each energy storage unit in FR is taken into account, and the technical characteristics are taken as constraints to realize the optimal distribution of FR demand among them. The verification of a hybrid energy storage station including six energy storage units with different technical characteristics shows that the proposed strategy can compromise the FR performance and cost of each energy storage, utilize the FR potential of different energy storage types, improve the system frequency performance, enhance the overall benefits of the energy storage station, and stimulate energy storage to provide better FR services.