Mathematical Modeling, Stability, Bifurcation Analysis, and Simulations of a Type-3 DFIG Wind Turbine's Dynamics with Pitch Control

In this paper, a type-3 Doubly Fed Asynchronous/InductionGenerator (DFAG/DFIG) wind turbine is considered for higher wind speeds with the pitch control activated. The purpose of the paper is to study the stability of wind turbine's when connected to the grid. The main blocks of the model that have been taken from the literature are described and translated into a system of differential equations with algebraic constraint. Time domain analysis for the system is provided by computing the steady states as functions of the wind speed and the grid parameters, testing eigenvalues sensitivity to the wind speed, and analyzing stability, including bifurcation in parameter space. The existence of a Hopfbifurcation for a practical value of the reactance is found and analyzed. Three groups of simulations are presented, time dependent wind speed, drop-clear terminal voltage, and a drop-clear case in reactance to show the bifurcation effect and thesystem's response to it.