Analysis of DFIG During Unsymmetrical Grid Fault by Using Crowbar Circuit

Throughout the last decade, the number of wind installations have increased greatly. One of them which has the most portion in penetration of wind turbines, is doubly fed induction generator (DFIG). Notwithstanding this variable speed machine's benefits, there are some inherent drawbacks. One of the most important concerns is to provide Low Voltage Ride-Through (LVRT) capability during different grid faults. In this paper, some solutions on this issue have been reviewed and a method is proposed to avoid the weaknesses of the other solutions. in order to compare these methods, a 9MW wind farm which consists of 6 DFIGs, connected to a grid, is studied in its normal condition and during an asymmetrical fault. The simulation results are attained by using MATLAB/ Simulink.