Frequency Cooperative Regulation of Doubly Fed Induction Generator and Synchronous Generator

Doubly fed induction generator (DFIG) with over-speed control has the ability to adjust output quickly, which is suitable for maintaining frequency stability in power system. Under the condition that the system suffers sudden power shortage, emergency frequency support can be provided to the system temporarily by it, which is more economical than relying on storage devices. In the designed system, synchronous generator (SG) and wind turbines are parallel connected to support the load, and the wind turbines play the role of providing emergency frequency support, cooperating with synchronous machines in an orderly manner. Finally, the studied system with 60% wind power penetration is established, and the effectiveness of the proposed strategy is verified by MATLAB/Simulink simulation. This operation strategy does not need to be equipped with large capacity energy storage device, thus optimizing the economy of the system operation. At the same time, excavating deeply the potential for frequency regulation of wind turbines helps system improve the frequency regulation performance.