Two-Variable Admittance Modeling of DFIG Considering All Wind Speed Conditions

Abstract

The stable operation capability of the doubly-fed induction generation (DFIG) based wind power grid-connected system will vary with the wind speed, yet the existing mathematical models of DFIG is limited to some specific wind speed points, which may not be directly applied to stability analysis in the all wind speed operating conditions. The wind speed is used to characterize the steady state operating point in this paper, while considering the single-input dual-output (SIDO) characteristics of DFIG, a two-variable admittance model are proposed. Further, the two-variable admittance model are used to analyze the stability of DFIG based grid-connected system. The simulation results indicate that the established admittance model can precisely reflect the frequency characteristics in the entire wind speed operating space, which provides basis for accurate analysis and effective improvement of the stability for new energy power generation equipment.