Implementation of Vehicle-to-Grid Scheme in Hydro-Dominant Grid Subjected to Ultra-Low Frequency Oscillations

This paper aims to improve the frequency stability in electric vehicles (EVs) penetrated hydro-dominant power grids. Such an environment is subjected to two significant technical challenges. On the one side, the occurrence of ultra-low frequency oscillations (ULFOs) has been frequently noticed in the last two decades. They are intrinsically caused by the hydropower plants and can lead to the hydro-dominant power systems' collapse. On the other side, EVs have demonstrated the ability to participate in the power system's frequency regulation by injecting stored power back in the grid. However, this contribution from vehicle-to-grid (V2G) has to match EV users' convenience. In this paper, the ability of a V2G system to participate in the damping of hydro-dominant grid ultra-low frequency oscillations is investigated. The occurrence of ultra-low frequency oscillations is successfully reproduced in the chosen test system. A comparison between the system with and without proposed V2G schemes is carried out, showing V2G schemes' positive effect on the grid frequency stability. The results are then shown and discussed to validate the effectiveness of the proposition in terms of damping the ULFOs while still satisfying EV users' convenience.