水泵水轮机全特性曲线的拟合--移动最小二乘近似

本文在基于曲面拟合的水泵水轮机全特性曲线的变换新方法的基础上 ,将移动最小二乘近似应用于对全特性的曲面拟合。通过最小二乘曲面拟合与移动最小二乘拟合的水泵水轮机全特性拟合曲面和“S”区域拟合情况的对比 ,以及抽水蓄能电站过渡过程计算结果与实测值的对比 ,发现移动最小二乘近似能够更好地拟合水泵水轮机的全特性曲线。最后对移动最小二乘近似参数权函数因子、计算点影响域中的节点数及影响域半径乘子对计算结果的影响作了分析 ,得出了初步的建议

A new simulation method of complete characteristic curves of reversiblepump turbine-moving least square approximation

In this paper,moving least square(MLS)approximation is applied to simulate the complete characteristic curves of reversible pump turbine based on the surface fitting.The comparison of computational results which include the surface fitting of complete characteristic of the unit and the computation of turbine load rejection in pumped storage plant shows that the computational precision by using MLS approximation is better than that of the least square(LS)surface fitting.It means that MLS is more appropriate than LS to simulate the complete characteristic curves of reversible pump turbine.In the end,the effect of MLS's parameters,such as coefficient of weight function,the number of points in the support domain and the scale of radius of the support domain on the computational results are analyzed and some suggestive conclusions are presented.