Ancillary Service by Tiered Energy Storage Systems

Due to intermittent characteristics and lack of inertia and damping properties, high penetration of renewable energy sources in power grids could bring about a series of security issues related to power system stability and control. In many countries and regions, therefore, power regulators tend to request self-frequency control ancillary services (FCAS) of renewable power generation, which could introduce further obstacles to utilize clean and inexhaustible wind power, solar energy, and the like in large scale. This paper aims to address such a challenge by presenting a tiered energy storage system (TESS) for self-provision of frequency regulation services. The TESS is composed of different types of energy storage devices aimed at rapid response speed, sufficient storage capacity, and acceptable investment/operation costs. The proposed method can be applied for the FCAS of power grids with high-penetration renewable energy integration. Based on the real wind power generation and electricity demand, simulations were carried out to demonstrate the feasibility of the self-FCAS by the developed TESS.