Abstract:In order to suppress the fluctuations of the rotor speed and electrical power of the doubly-fed induction generator (DFIG) system when it works at a wind speed greater than the rated value, a new coordinated regulation strategy is proposed using the coordinated passivity techniques, with the pitch angle regulation and excitation voltage control simultaneously considered. First, based on analysis of the characteristics of wind turbines and the basic electromagnetic relationship of DFIGs, a four-order nonlinear model was established for regulation of the pitch angle and control of the excitation voltage of DFIGs. In particular, the formula of the wind power utilization coefficient and pitch angle was fitted with the polynomial function, and the uncertainty of the fitting result was modeled, ensuring the high accuracy of the system model. Secondly, pitch angle control was realized based on design of the former two orders of the robust controller using the Lyapunov techniques, and excitation voltage control was achieved based on the coordinated passivity techniques. Thus, the passive feedback of the whole system was obtained, and the system is both robust and tends to be stable. The simulation results validate the effect of the control strategy. The effectiveness of the present control strategy was also verified by its comparison with other control strategies.