Modeling of Wind Turbines Equipped with Doubly-Fed Induction Machines for Power System Stability Studies

This paper deals with the modeling of the doubly-fed induction generator (DFIG) for stability studies. Using the space-phasor representation and the underlying quasi stationary model, suitable control algorithms for the simulation of the DFIG operating on an interconnected system is developed. The schemes include the pitch-angle/speed control and the decoupled control of the real and reactive power outputs. The model is then implemented on a large test network. Simulations have been carried out to study the control behavior of wind turbines to wind speed changes and the response to three phase grid faults. The results demonstrate the suitability of the models and the overall control architecture for stability studies and give insight into the scope of possible targeted control interventions. The short-circuit test in particular highlights the relationship between the control philosophy adopted and the possibility of the DFIG actively participating in supporting the network voltage