An Analytical Approach to Energy Storage Sizing for Inertia and Frequency Reserve Support

Abstract

Large-scale integration of renewable energy resources (RER) in the power system can lead to the displacement of conventional generation systems, consequently reducing the system inertia response (IR) and primary frequency reserve (PFR). The energy storage systems (ESS) can help improve the frequency stability of RER integrated systems by proving IR and PFR support. In this paper, an analytical method to size the ESS for IR and PFR support of RER integrated systems is proposed. The proposed method presents an analytical model to reevaluate the system parameters considering the reduction in system inertia and equivalent frequency regulation due to RER integration. The reevaluated parameters are then solely used for ESS size estimation, resulting in a computationally inexpensive ESS sizing algorithm. The proposed method is applied to the WSCC 9-bus system where the ESS sizes are estimated with varying RER integration levels and a sensitivity analysis is performed to evaluate the performance of estimated ESS sizes in IR and PFR support modes.