Source-sink Localization Analysis of Sub-synchronous Oscillation between Substations

With the development of new energy, the sub-synchronous oscillation accidents caused by the grid connection of large-scale wind farms have seriously affected the safe and stable operation of the power grid. Timely analysis and summarization of oscillation accidents are of great significance to ensure the safety of power electronic equipment and the stable operation of the system. In this paper, taking a typical large-scale wind farm grid-connected system as an example, the electromagnetic transient model is analyzed for the forced-type sub-synchronous oscillation problem. Then, the oscillation source and sink are determined through the harmonic power flow analysis method and the harmonic frequency impedance analysis method. Furthermore, by adding a serial compensation device, observe the changes in the source and sink of sub synchronous oscillations. Finally, it is concluded that under forced disturbances, the system will generate new oscillation sources, and some wind farms in the system may also become excitation sources for oscillations. The addition of series compensation equipment will affect the changes in oscillation sources, providing reference for handling practical cases.