Frequency drops mitigation at high wind energy penetration by hydro-pumped storage — Capacity sizing

Expected wind energy high penetration levels in power systems require robust and practical solutions to improve typical conventional systems performance or at least maintain it. Wind farms positive contribution in eliminating grid frequency deviations still a grey area, especially, when wind farms replace considerable conventional generation capacities. This paper offers a detailed algorithm to integrate a hydro pumped storage facility to provide power support during frequency events and also absorb/inject active power to smooth wind power fluctuations. First part of offered research work, presented by this paper, estimates the rated power and energy capacities based on several constrains, including wind speeds and load characteristics. The second part discusses the impact of integrating suggested storage plant on frequency and power smoothing. Additionally, the criterion controlling energy storage and injection by storage plant is highlighted. Considered case study represents a defined sector from a genuine conventional grid merged with real wind speeds records at recommended locations to host wind farms. Results reveal the major technical aspects of required storage facility (e.g., number of pumps, reservoir height and volume as well as integrated generator(s) specifications). MATLAB and Simulink are the implemented simulation environments.