Grid Frequency Response of Different Sized Wind Turbines

In many power systems like for instance the Continental European synchronous area of the ENTSO-E, wind power is replacing conventional (thermal) generation. Because wind power does in general not show inertial response and does not provide control power, the ability of the entire system to withstand power disturbances deteriorates. Under the event of a large generation outage in a system with large scale wind power, grid frequency limits could be exceeded which affect controllability, stability, and reliability of power system operation. Therefore, there is an incentive that wind turbines participate in balancing power. Previous research showed that control systems can enable participation of wind turbines in balancing, using their kinetic energy. It was also perceived that different sized wind turbines have different capacities to support the system. This research elaborates on previous work and shows that wind turbines equipped with adequate control systems can provide nearly identical grid frequency response as conventional power plants, independently of the size of the wind turbines. This work shows that system stability can be maintained even with large scale wind power integration. The grid frequency drop which immediately originates after a large generation outage will not worsen due to wind power, which consequently will not threaten the current power system operation.