Fitting method and system for roughness and friction speed of wind power plant

The invention discloses a method and a system for fitting roughness and friction speed of a wind power plant, and belongs to the technical field of wind power plant weather forecast. The method comprises the following steps: acquiring wind speed measured data of a plurality of observation floor heights of a wind power plant, establishing a wind power plant atmospheric stability discrimination model, substituting the wind speed measured data into the wind power plant atmospheric stability discrimination model, and calculating to obtain a wind shear index of the wind speed measured data; according to the wind shear index, screening out data meeting a neutral stable state from the wind speed measured data; and substituting the data meeting the neutral stable state into a logarithmic law wind profile model, and performing fitting solution by using a least square method to determine the roughness and friction speed of the wind power plant. According to the method, the accurate roughness and friction speed of the w