With the increasing penetration of wind power into electric power grid

large scale integration of the doubly fed induction generator (DFIG) in wind farm and its low voltage ride-through (LVRT) capability stipulated stringently in the revised grid code have led to extensive researches on the detailed theoretical analysis of the DFIG dynamic characteristics and its LVRT enhancement capability. However

no matter whether mathematical analysis or simulation calculation was used in previous investigations

different kinds of negligence and assumptions have emerged

such as neglecting stator resistance or assuming the same leakage inductance between stator and rotor sides

which will result in different influences on the accuracy and validity of the dynamic characteristics analysis and the LVRT control design. In order to overcome these drawbacks

a completely accurate mathematical dynamic DFIG model is developed during the three-phase voltage dips without any negligence

and different interactivities between the generator’s rotor parameters and the damping speed and degree of the generator’s electro-magnetic variables have been derived. Based on the proposed calculation and analysis

the improved Crowbar circuit prototype and the optimal parameters design of the Crowbar are given. The simulation results in MATLAB/ SimuLink have totally verified the validity and efficiency of the theoretical calculation and the proposed scheme.