Control Strategy of Hybrid Energy Storage System to Improve AGC Performance of Thermal Generator

Due to the increasing penetration of renewable power generation, the decreasing inertia of power system incurs frequent frequency fluctuation. Considering the limited performance of traditional thermal generator and insufficient reserve capacity, frequency regulation cannot be effectively addressed. In such a case, owing to the ability of fast response, energy storage system (ESS) is regarded as a feasible way to work with traditional thermal generator to promote the total performance. In this paper, a novel control strategy of hybrid energy storage system (HESS) is presented aiming to improve the AGC response speed and precision of HESS-generator system. Case studies are carried out to demonstrate the performance of the proposed method.