Contribution of Energy Storage Systems to Long-Term Power System Dynamic Performance

This paper discusses the impact of energy storage systems (ESSs) on long-term power system frequency deviations originated by real-time electricity markets with short dispatch periods. The goal of the paper is to evaluate whether and under which conditions ESSs are effective in reducing these frequency deviations. With this aim, the paper first discusses a dynamic market model with inclusion of ESSs. Then, it provides a comprehensive sensitivity analysis of the ESS control parameters based on time domain simulations. Results indicate that ESSs can significantly reduce the long-term frequency deviations. However, the capacities of the ESSs as well as the deadband and droop coefficient of the ESS controllers have to be carefully designed to avoid the outbreak of unexpected dynamic behaviors.