Research On A Stand-alone Wind Pumped Storage Hydropower Plant

Wind power has characteristics of random volatility, intermittency, varing seasonal and climate. As a kind of uncontrollable power, the increase of wind power penetration in the power system will impact the stability of power system operation and power quality. In order to ensure the safe and stable operation of the power system, each power grid has specific restrictions with the capacity of integration of wind power. This restriction will restrict the wind development and cause "abandon wind". In order to improve the utilization of renewable energy, researches are being carried out to find out the new way to improve wind power penetration in almost all countries.As is well-known, energy storage device in the power system is the effective method to restrain the wind power fluctuations, and using pumped storage system in a power system is one of ways to raise the wind energy penetration. Studies have been done to introduction a pumped storage system in power system which aims mainly at peak clipping, valley filling of a grid and so on. In this study, a relatively novel solution is introduced to enable wind-hydro-pumped storage station to generate power energy like a conventional generation unit so as to maximize wind energy penetration. With reasonable configuration, it can serve not only as conventional power source but also as peak regulation. Based on the specific island data, the components of wind pumped storage system, mode of operation, operation efficiency, the system stability are studied in this paper.Firstly the feasibility wind pumped storage system operating as a conventional the hydropower station is studied. Energy transforming efficiency is calculated and analyzed in three kinds of operation mode and the feasibility of the system is demonstrated using local hydrology, meteorology, reservoir, electric power system and other data under the proposed system framework.Then the efficient operation schemes of the pump in the fluctuation of energy are discussed. The structures of wind pumped storage system and driving system of pump group, with high energy conversion efficiency, and the connection mode and control strategies are proposed. Then the simulation model of the system is set up in MATLAB/SIMULINK, and dynamic simulation analysis of several critical state when it is operating, such as system startup, variable pump operation and switch, etc, are put up, verifying the operation feasibility and stability of the standalone system.