Research on the Substitution Ability of Battery Energy Storage system for Thermal Power Units in Frequency Regulation

When penetration levels of renewable energy of power system are increased, the proportion of thermal power units will gradually decrease. This will cause the frequency regulation capacity of the power system to gradually decline. To this end, battery energy storage systems are widely used to frequency regulation in the power system. However, the frequency regulation ability of battery energy storage system to substitute thermal power units has not yet been quantified. In this paper, it introduces two frequency regulation method models. In the proposed models, the influence of different energy storage participation degrees on the effect of frequency regulation is analyzed, and a power and energy indicators system for quantifying energy storage substitution ability is proposed based on the advantages of frequency regulation with energy storage. The simulation results indicate that the ability of energy storage to substitute thermal power units is about 20-35 in terms of rapid energy supply when the installed capacity is same.