Renewable energy resources (RERs) are widely embedded in the power system due to the fossil fuel depletion, economic and environmental issues. The permanent magnet synchronous generator (PMSG) is considered one of the most promising technologies for the wind energy conversion system (WECS). However, in case of faults occurrence the behavior of the PMSG will be changed considerably. The crowbar protection is the most common used for reduce the negative effects of the faults. The resistors of the crowbar should be determined preciously to ensure the best performance of the WECS based PMSG based during the system faults. The aim of this paper is to investigate the performance of the WECS based PMSG under grid faults with optimal integration of the Crowbar protection system. The Lightning Attachment Procedure Optimization (LAPO) is employed to find the optimal values of the crowbar's resistors to mitigate the fault effects. The simulation results reveal to that the performance of the WECS based PMSG can be enhanced considerably with optimal inclusion of the crowbar protection in terms of the stator current, the DC voltage, the delivered active and reactive powers to the grid under faults of states.