Under the background of the vigorous development of the new power system with the theme of new energy

wind power has been significantly developed. Wind power has become one of the main sources of renewable energy. The series compensation method can effectively improve the transmission capacity of transmission lines by connecting capacitor bank with transmission lines

which is the preferred way for large wind power plants to connect to the grid. However

the disadvantage of the series compensation method is that it increases the possibility of sub synchronous oscillation of the system. For studying the suppression method of sub synchronous oscillation and as for the problem of sub synchronous oscillation caused by induction generator effect in doubly fed wind farm in this paper

the generalized Nyquist analysis method based on impedance analysis is used to deduce and analyze the sub-synchronous oscillation phenomenon of wind farm

and an integral coefficient is added to the rotor side of the system to increase the damping of the system. Finally

the wind farm equivalent system is set up in Matlab/Simulink

and the accuracy of the theoretical analysis and suppression strategy is verified by simulation.