基于控制体—迎风有限元法的变压器绕组二维流体场—温度场耦合计算方法研究

Study on Coupled Calculation Method of Two Dimensional Fluid and Temperature Field of Transformer Winding Based on Control Volume-upstream FEM

针对电力变压器二维流体场和温度场的耦合问题,文中采用了基于控制体有限元法和迎风有限元法的流体场—温度场耦合计算方法。该耦合方法基于三角形网格,使用控制体有限元法计算绕组油流区域的速度场,应用流线迎风有限元法求解整体场域的温度分布。在速度场计算中引入速度提升方法解决了流体场仿真时出口边界出现的回流流动问题,并在温度场计算时提出了适用于线性三角形单元的流线迎风稳定参数取值方法,从而解决了温度场仿真时的数值振荡问题。应用所提方法计算分析了油浸式变压器绕组二维模型的油流及温度分布,并将计算结果与Fluent软件仿真结果进行了对比,对比结果验证了耦合方法的有效性。文中提出的二维流体场和温度场耦合场计算方法也可用于其他二维流体场和温度场耦合问题的分析。

In view of the coupling of the two-dimensional fluid field and temperature field in power transformer,the fluid field-temperature field coupling calculation method based on control volume finite element method and upwind finite element method is adopted in this paper.The coupling method is based on triangular mesh.The control volume finite element method is used to calculate the speed field in the oil flow area of the winding and the streamline upwind finite element method is used to solve the temperature distribution in the whole field.In the calculation of speed field,the velocity lifting method is introduced to solve the problem of the return flow at the outlet boundary in the simulation of fluid field.In the calculation of temperature field,a method of choosing the parameters of streamline upwind stability suitable for linear triangular elements is proposed so to solve the problem of numerical oscillation in the simulation of temperature field.The oil flow and temperature distribution of the two-dimensional model of oil-immersed transformer winding are calculated and analyzed by the proposed method.The results are compared with the sult.The calculation method of two-dimensional fluid field and temperature field coupling field presented in this paper can also be applied to the analysis of other two-dimensional fluid field and temperature field coupling problems.