Abstract: In this paper,the trajectory sensitivity method is extended by introducing the DFIG. With the integral of the relative deviation of the SG’s mechanical power taken as the objective function,the gradient information is obtained by the trajectory sensitivity analysis. The parameters of the low pass filters are optimized based on the interior point method. The simulation results show that the extended trajectory sensitivity method has higher accuracy,and can quantify the influence of frequency control of the DFIG on the transient stability of the system. The parameter optimization improves the transient power angular and frequency stabilities of the wind power system simultaneously.