基于自适应网格控制的10 kV油浸式变压器多物理场仿真计算

Simulation of Multi-physical Field of 10 kV Oil-immersed Transformer Based on Adaptive Grid Control

为避免变压器多物理场计算过程中全局加密带来的网格冗余,提出一种基于误差分析的网格自适应剖分方法。首先采用棱边有限元法进行磁场分析确定变压器损耗分布,进而采用有限体积法进行温度流体场分析确定变压器初始温度流体场分布,基于提出的变压器温度流体场计算单元误差计算式,可有针对性地提取出变压器温度流体场计算过程中数值计算误差大的单元,从而实现网格的自适应加密。分别以x、y、z方向上流体流速为误差控制量,进行3次网格自适应加密,第3次自适应加密后的整体网格是全局加密下网格数量的65.6%,计算时间缩减36.0%,同时变压器各测温点以及绕组热点温度计算值与温升试验值之间的最大绝对温差不大于3℃,验证了仿真结果的准确性。研究为变压器多物理场计算网格质量优化控制提供参考。

In order to avoid the grid redundancy caused by global encryption in the calculation of multi physical fields of transformer,an adaptive grid generation method based on error analysis is proposed in this paper.Firstly,the loss distribution of transformer is determined by magnetic field analysis based on edge finite element method.Then,the transformer initial thermal fluid field distribution is determined by the finite volume method.Based on the error calculation formula of transformer temperature fluid field calculation element,the elements with large numerical calculation error in the calculation process of transformer temperature fluid field can be extracted,so as to realize the adaptive mesh refinement.The fluid velocity in x,y and z directions is taken as the error control variables,and the grid is adaptively encrypted for three times.After the third time,the whole grid is 65.6%of the number of grids under global encryption,and the computing time is reduced by 36.0%.At the same time,the maximum absolute temperature difference between the calculated value and the test value of transformer temperature measurement points and winding hot spot temperature is not more than 3℃,which verifies the accuracy of the simulation results.The research of this paper can provide reference for the mesh quality optimization control of transformer multi physical field calculation.