In recent years, wind power generation has been attracting attention due to concerns about global warming. Among them, double-fed induction generators (DFIGs) are widely used as wind power generators because of their low cost and excellent controllability. However, it is very important to improve the fault ride-through (FRT) capability of DFIGs because they are very sensitive to grid faults. One of the methods to improve the FRT capability of DFIG is to suppress the rotor overcurrent by using a Crowbar. In order to improve the FRT capability of the DFIG, the crowbar can be used to suppress the rotor overcurrent. On the other hand, if the release timing is not appropriate, the overcurrent will recur, so the release timing of the crowbar is important. In this study, we propose a method to derive the optimal timing to release the Crowbar. In addition, the effectiveness of the proposed method is demonstrated by simulation.