计及功率与导叶开度非线性特性的混流式水轮机改进模型

Improved Francis Turbine Model Considering Nonlinear Characteristics between Hydro-turbine Power and Guide Vane Opening

针对现有理想水轮机模型和解析非线性水轮机模型不能反映混流式水轮机组功率与导叶开度间的非线性特性问题,建立了计及功率与开度非线性特性的混流式水轮机改进模型。该模型基于水轮机解析非线性模型,加入了功率与开度非线性关系模块,分析比较了功率与开度的不同拟合方法,推荐采用三次多项式拟合方法更适用于功率与开度拟合,并通过机组频率扰动试验、功率升降试验、一次调频试验和电网故障扰动试验仿真及实测结果表明,与理想水轮机模型和解析非线性水轮机模型相比,计及功率与开度非线性特性的水轮机改进模型精度更高。

In view of the existing ideal turbine model and analytical nonlinear turbine model can not reflect nonlinear characteristic curve between Francis turbine power and guide vane opening,improved Francis turbine model is established by taking into account nonlinear characteristics of power and guide vane opening.Based on the analytical nonlinear turbine model,the improved turbine model added module of nonlinear relationship between power and guide vane opening.Different fitting methods of power and guide vane opening are analyzed and compared,and cubic polynomial fitting method is more suitable and recommended.Through frequency disturbance test,power raising and lowing test,the primary frequency disturbance test and power grid fault disturbance test,simulation and measured results show that compared with the ideal turbine model and analytical nonlinear turbine model,the accuracy of improved turbine model considering nonlinear characteristics of power and guide vane opening is higher.