Study on electromagnetic transient characteristic of DFIG during voltage dip

In wind power system, the fault ride-through capability of doubly fed induction generators (DFIG) has draw a lot of attention. For analyzing the electromagnetic process of DFIG and influence of saturation of magnetic circuit on transient process during voltage dip, the mathematical model coupling two-dimension finite element method(FEM) with circuit equations was presented and used to simulate the transient process of DFIG. This paper simulated the transient process of generator while the different grid voltage dipping conditions, analyzed electromagnetic characteristic in transient process, and studied influence of different end leakage reactance on transient process. It is concluded that increasing stator leakage reactance can weaken DC component of flux linkage during the transient process of voltage dip, so limit the amplitude of transient current. The work can provide some useful reference for controlling wind power system when grid voltage dips.