With the increasing scale of power system interconnection, the increase of wind power grid capacity has more and more influence on the stable operation of a power system. The wind power mathematical model of a FACTS device represented by UPFC and SVC are constructed. The FACTS device is positioned by residue index, and an additional damping controller is designed. Then, the effect of the FACTS device on the low-frequency oscillation of the wind power system is analyzed based on the IEEE 2-area 4-unit system by employing eigenvalue analysis and dynamic time-domain simulations. Simulation results show that system's bus voltage and the stability of the generator speed can be maintained using the FACTS device with ADC. On the other hand, the range of the tie-line power of the interconnected system is increased, the fluctuation of power network parameters caused by low frequency oscillation is suppressed, and the low-frequency oscillation characteristic of the wind power system is improved. This work is supported by National Natural Science Foundation of China (No. 51507157 and No. 51607158), Henan Science and Technology Research Project (No. 202102210305), and Project Foundation for Young Key Teachers of Henan Colleges and Universities (No. 2017GGJS093).