A resilience enhanced hierarchical strategy of battery energy storage for frequency regulation

Abstract

Battery energy storage system (BESS) has been regarded as an effective technology to regulate system frequency for power systems. However, the cost and the system security of battery energy storage are the bottle necks for the battery energy storage system to be applied to practical projects for frequency regulation. Comparing with the large-scale battery energy storage system, the small-scale energy storage system has better robustness and could reduce the cost and improve the system security with lower energy capacity and wider regional distribution. However, coordinating the state of charge (SOC) of a large number of small-scale battery storage system to provide effective frequency regulation service is a challenge for the operation of power systems. In this paper, a hierarchical energy management strategy, which can be applied to different scenarios with and without limited communication systems, has been proposed to coordinate a large number of small-scale energy storage systems to regulate frequency for power systems. The rated power capacity, energy capacity, and SOC of the BESS are considered in the proposed strategy to maximize the capability of frequency regulation for power systems. The proposed strategy can be applied to power systems without powerful and expensive communication systems and coordinate BESS according to SOC of the BESS and the quality of communication system. The resilience of power systems after extreme natural events can be enhanced by the frequency regulation service of BESS under proposed strategy.