1.哈尔滨工业大学电气工程及自动化学院,黑龙江省哈尔滨市 150001;2.上海建坤信息技术有限公司，上海市 200032
1.School of Electrical Engineering and Automation, Harbin Institute of Technology, Harbin 150001, China;2.Shanghai Jiankn Information Technology Company, Shanghai 200032, China
This work is supported by National Key R&D Program of China (No. 2018YFB0904000) and National Natural Science Foundation of China (No. 51977046, No. 51977040).
A compensation control strategy for doubly-fed induction generator (DFIG)-based wind turbine based on disturbance compensation of grid voltage is proposed in this paper to solve the stability problem of grid-connected in weak grid. Firstly, a unified impedance model of DFIG-based wind turbine is established in the synchronous reference frame including rotor side converter (RSC) and grid side converter (GSC). Then, based on the established impedance model, the transfer relationship between the point of common coupling voltage and the controller output is analyzed, the voltage disturbance compensation is introduced into the current loop of RSC and GSC respectively to improve the converter control. The generalized Nyquist criterion (GNC) proves that the proposed method can effectively improve the grid-connected stability of DFIG-based wind turbine in weak grid. Theoretical analysis shows that the compensation control of RSC and GSC based on the point of common coupling voltage disturbance compensation can improve the impedance characteristics of DFIG so as to improve their stability under weak grid condition. Finally, the effectiveness of the proposed compensation control method is verified by simulation.