WT Modelling with DFIG for Transient Analysis Focusing in UMEC Model of Power Transformer

The aim of this paper is the analysis of the behaviour of a Wind Turbine (WT) with a Double Fed Induction Generator (DFIG) dynamic model, where the transformer is modelled either by an electrical circuit model or by a Unified Magnetic Equivalent Circuit (UMEC). The grid model includes this transformer and a voltage source. The parameters of the UMEC model have been obtained from name-plate data, the datasheet and the manufacturer of the power transformer. Such transformer model also includes the effects of the core saturation characteristic (V-I curve). Finally, the transient state of WT with DFIG is analyzed when a voltage dip occurs, because during these faults appear over currents due to the changes in the magnetic fluxes of the DFIG and these kind of faults can cause that the transformer works in the saturation part of their characteristic curve. The simulation results are used to show the reliable operation range of the conventional transformer model representation.