Adequate Crowbar for Enhancing the Performance of Squirrel Cage Induction Gnerators Wind Farms

The asynchronous wind farms are based on squirrel cage induction generators (SCIG/WF). The main disadvantage of SCIG/WF is the deeply affected by the faults which may occur in the interconnected grid. These conditions can lead to disconnect SCIG/WF from the grid. The crowbar has been used effectively in protecting the stator or rotor coils of doubly fed induction generators (DFIG) which are used in variable speed wind farms. The large value of crowbar causes an overvoltage after fault removal. In this paper, a developed method is used to enhance the performance of SCIG/WF during the grid faults. The developed method is based on using the crowbar as outer protection to equip save path for the fault current. This method is proposed to investigate the value of crowbar which can prevent SCIG/WF from disconnection, limiting the current at the contact point between SCIG/WF and grid. The impact of adequate crowbar on SCIG/WF is investigated during symmetrical fault (Three phase fault) and unsymmetrical fault (double line) using MATLAB Simulink program.