Real-Time Reactive Power Regulation Capacity Assessment of DFIG Wind Farms

The output power of wind farms fluctuates with the wind speeds, which result in unstable voltage at the point of common coupling. The fast reactive power regulation capability of the variable speed wind turbine generators is an effective solution to suppress voltage fluctuation at the point of common coupling. The reactive power regulation capability of the variable speed wind turbine generators varies with their operation status. In order to design an effective voltage control method for the wind farms, it is of great significance to evaluate real time reactive power regulation range of the wind farms. In this paper, a doubly-fed wind turbine generator model is established, the reactive power limit of the wind turbine generator is derived. Then, the wind farm reactive power loss and reactive power compensation equipment capacity are considered to establish the wind farm reactive power capacity estimation model. Finally, the wind turbine equivalent model is used to simulate natural wind speed to obtain the real-time reactive power capacity range of the wind farm under random fluctuating wind speed, and the simulation results verify the reliability of the proposed method.