Assessing transient response of DFIG-based wind plants - The influence of model simplifications and parameters

There has been a fast growing demand for the application of doubly fed induction generators (DFIG) in wind power plants in recent years. They have in particular dominated the market in last two years. DFIG is an ideal candidate to satisfy the requirements of the recently proposed challenging grid codes. However, many uncertainties still exist or at least there are no published reports regarding validated comprehensive DFIG models. This paper attempts to clarify the existing ambiguities in modelling of DFIG under various operating conditions using the power system analysis package DIgSILENT PowerFactory. This paper uses available DFIG models and investigates/demonstrates the influence of various model parameters and simplifications (for both mechanical and electrical subsystems) on DFIG-based wind plant transient responses. It further explores and compares the performance of different crowbar protection and rotor side converter restart schemes. Realistic operational limits, such as current margins and PWM modulation limits, are taken into account in all simulations.