Surface Construction of Hydro Turbine Transfer Coefficients Based on Radial Basis Function Fitting Interpolation Method
The unit model in simulation calculation of hydraulic turbine governing system mainly adopts simplified model,ignoring the nonlinear characteristics of turbine,which makes it difficult to accurately reflect the actual operation process of turbine.The difficulty of constructing hydraulic turbine nonlinear model depends on the accurate acquisition of hydraulic turbine transfer coefficients for different operating conditions.Firstly,the expression of hydraulic turbine trans-fer coefficient was derived based on the comprehensive characteristic curve of hydraulic turbine model.Then,the radial basis function fitting interpolation method was introduced to reconstruct and mesh the comprehensive characteristic sur-face of the hydraulic turbine model.The effects of different radial basis kernel functions on the fitting interpolation accu-racy of hydraulic turbine model comprehensive characteristic curve were compared.Finally,the turbine transfer coeffi-cient surface was constructed,and the influence of the fitting interpolation error of the comprehensive characteristic curve of the hydraulic turbine model on the accuracy of the hydraulic turbine transfer coefficient solution was analyzed.The re-sults show that the mean relative error of resampling can be controlled within 0.005 by using the radial basis function fit-ting method to reconstruct the comprehensive characteristic surface of the hydraulic turbine model.The accuracy of the transfer coefficient of the turbine under different working conditions is higher.
万方数据
维普
