Coordinated Microgrid Frequency Regulation Based on DFIG Variable Coefficient Using Virtual Inertia and Primary Frequency Control

• Published in: IEEE transactions on energy conversion Vol. 31; no. 3; pp. 833 - 845
• Main Authors: Zhao, Jingjing, Lyu, Xue, Fu, Yang, Hu, Xiaoguang, Li, Fangxing
• Format: Journal Article
• Language: English
• Published: New York IEEE 01.09.2016; The Institute of Electrical and Electronics Engineers, Inc. (IEEE)
• Subjects: Coefficients; Diesel; Distributed generation; Doubly fed induction generators; Frequency control; Generators; Inertia; microgrid frequency regulation; Microgrids; primary frequency control; Rotors; Strategy; variable coefficient; virtual inertia control; Wind power generation; Wind speed; Wind turbines
• ISSN: 0885-8969; 1558-0059
• DOI: 10.1109/TEC.2016.2537539

This paper proposes a variable coefficient combined virtual inertia and primary frequency control strategy for doubly fed induction generators (DFIG) in coordination with diesel generator to participate in wind/photovoltaic/diesel microgrid frequency regulation. The frequency response characteristic is analyzed under different wind speeds with corresponding inertia control parameters different. A 10% wind power margin is preserved through overspeed control and pitch angle control to offset the decrease of wind output power after temporary extra power surge, and provide a permanent frequency support for microgrids. The influence of droop control gain setting is also illustrated under different wind velocities. By continuously adjusting the control parameters according to wind speed variation, a variable coefficient method is realized. The method can guarantee an efficient implementation of this strategy in time-varying conditions. Finally, this coordinated control strategy is tested in a storage-independent microgrid with solar, wind, and diesel generators.