Small disturbance angle stability indication in the electrical networks with variable speed wind turbines

The fast growing application of sustainable energy sources imposes major structural changes on the current electric power systems. One of these structural changes is to make use of large variable speed wind turbines within the conventional electrical power networks. The installation of these wind turbines has, indeed, indispensable impacts on the dynamic behavior of the existing electric power systems. Thus, it is important to gain a rather generalized overview on how these wind turbines, which mostly use Doubly Fed Induction Generators (DFIGs), affect the system stability. This paper performs an analytical analysis for the indication of small disturbance rotor angle stability in the power systems equipped with variable speed wind turbines using DFIGs. Also, in order to consider the stochastic characteristic of the sustainable energy sources, the paper applies an iterative-stochastic method to analyze the small disturbance angle stability. The suggested iterative-stochastic methodology is numerically verified, within this paper, by getting applied to an electric power test system.