With the rapid development of large-scale wind power

the cluster wind power base has been initially built in scale in Hami area of Xinjiang. But since the wind power is at the end of the power grid

the grid structure is weak and shows the collusion relay power supply;therefore the volatility and randomness of wind power have a great impact on the safe and stable operation of power grid. Especially in recent years

the generation mechanism of the asynchronous oscillation（including sub synchronous oscillation and super synchronous oscillation）occurred in DC near area and wind power concentrated area is not studied clearly. In this paper

the extraction method of sub synchronous oscillation component is analyzed with combination of transient and steady recording data of sub synchronous oscillation on-line monitoring device and the different reasons on the transient and steady data result is analyzed and studied. The aspects should to be concerned about for using transient steady state data to analyze the multi-mode and asynchronous oscillations are presented. It has laid a solid foundation for the largescale development

operation and optimization of wind power

and has important reference value for the analysis and control of the asynchronous oscillation of a large number of power electronic components.