A new approach for low voltage ride through capability in DFIG based wind farm

Protection against voltage dips is very important for transient stability in a Doubly Fed Induction Generator (DFIG). Conventional crowbar circuits have been used for protection of DFIGs; however, they may be insufficient in some transient situations. Therefore, the Low Voltage Ride Through (LVRT) capability was enhanced by a Demagnetization Current Controller (DCC) for the purpose of transient analysis. In addition, both stator and rotor circuit electromotive forces were modeled in a DFIG. The performances of the DFIG models with and without the DCC were compared. Modeling was carried out in a MATLAB/SIMULINK environment. A comparison of system behaviors was made between three-phase faults with and without a stator–rotor dynamic. Parameters for the DFIG including output voltage, speed, electrical torque variations and d–q axis rotor–stator current variations in addition to a 34.5 kV bus voltage were examined. It was found that in the DFIG model the system became stable in a short time when using the DCC.