Filtering method for preprocessing fitting data of power curve

The invention provides a filtering method for preprocessing fitting data of a power curve. The filtering method includes: A, obtaining wind speed for fitting the power curve and power data corresponding to the wind speed; B, sectioning the data of the wind speed; C, determining an upper filtering limit and a lower filtering limit in each wind speed section; and D, filtering the data according to the upper filtering limit and the lower filtering limit. Actually measured historical data are utilized for fitting power curvature, abnormal data in the historical data are removed by means of setting the upper filtering limit and the lower filtering limit, and accordingly the power curve obtained by the aid of the fitted historical data can reflect actual performances of a unit, and accurately predicts and assess power generation capability of the unit.