Two-Variable Admittance Model for D-PMSG-Based Wind Turbine and Stability Criterion Based on Magnitude and Phase Contour Plot.

Recently, wind power technology has been developed rapidly. The interaction between the wind turbine generator and the grid may cause the stability issue and threats the reliable operation of the power system. So, it is vital to analyze the stability of the wind power grid-connected system. Due to the fluctuation of wind speed, the operation characteristics of the system vary, and the system exhibits different stability characteristics at the varied operating points. Thus, it is important to analyze the system stability in the entire operation space. The impedance-based analysis is an effective tool for the stability analysis of the grid-connected system. However, it is difficult to apply the conventional impedance/admittance model to characterize the system performance due to the fact that the system operating point often varies continually. To overcome this challenge, this paper proposes a two-variable admittance model that incorporates the wind speed into the conventional admittance model. In addition, a new stability criterion based on the magnitude and phase contour plot is developed to enable the stability analysis. Simulation and experimental results are presented to demonstrate that the proposed two-variable admittance model and the stability criterion are effective tools for stability analysis of the wind power grid-connected system. [ABSTRACT FROM AUTHOR]