Coupled Field–Circuit Modeling and Analysis for Interturn Short-Circuit Faults in a DFIG

Doubly fed induction generators (DFIGs) are the most preferred for use in wind turbine applications, and their internal faults will negatively impact the power grid. In this paper, a coupled field–circuit model for a stator interturn short-circuit (ITSC) fault inside a DFIG is presented, in which the bidirectional interaction between the field domain and the circuit domain is captured. The control system of the DFIG is directly integrated into the calculated model. Meanwhile, the black box arc model is used to simulate the time-varying arc conductance between the shorted turns. As a study case, a typical 1.5 MW DFIG was modeled and subjected to a stator ITSC fault. The results including flux density distribution, terminal currents and short-circuit current were given. The developed model and representative findings enrich fundamental studies on the internal faults of DFIGs.