变压器铁芯等效磁导率的反演计算方法

Equivalent magnetic permeability inversion calculation method of transformer core

采用有限元法分析变压器电磁问题时，往往忽略铁芯的叠片结构，将铁芯简化为同种材料构成的整体，铁芯等效磁导率的取值直接影响着仿真计算的精度．将电磁场有限元方法与智能遗传算法相结合，研究了铁芯等效磁导率的反演计算方法，研究结果表明，即使是非取向硅钢片，铁芯简化模型的等效磁导率也表现出方向性，取与硅钢片平行方向的磁导率等于单片硅钢片磁导率，与硅钢片垂直方向的等效磁导率略小于单片磁导率，可有效提高有限元法分析变压器电磁问题的精度．

The finite element method （FEM） has been widely applied to the magnetic field analysis of transformer. To reduce calculating amount, the core which is made of silicon steel sheet, the core is usually simplified as homogeneous material as a whole. The equivalent value of magnetic permeability of the simplified core is very important which directly related to the computing accuracy. In this paper the equivalent magnetic permeability parameter inversion method is studied using the smart genetic algorithm and FEM. The results show that the equivalent magnetic permeability of simplified core should has inhomogeneous property;in the direction parallel to steel plate, the core magnetic permeability should equal to steel sheet; on the other hand, in the perpendicular direction, the equivalent core magnetic permeability should slightly smaller than that of a steel sheet. The accuracy of FEM can be improved effectively.