Abstract: The accurate positioning of the oscillation center is the basis for correct action in out-of-step protection.Large-scale wind power integration causes system impedance parameters to change, resulting in a serious deterioration in the adaptability of the traditional out-of-step positioning method based on the impedance trajectory. To tackle this problem, an out-of-step oscillation center location method based on bus frequency is proposed. First, the influence of large-scale wind power integration on the total impedance of the system is analyzed. Further, from the power angle of the generator, the Manhattan distance similarity is calculated and a start-up criterion is constructed. Finally, the moving average method is used to smooth the wide-area measurement frequency, and an out-of-step oscillation center location method based on node frequency difference is proposed. Simulation results show that the proposed method is less affected by noise and is not affected by wind power penetration rate, and can accurately locate the out-of-step oscillation center.This work is supported by the National Natural Science Foundation of China（No. 52077120）.