Error Correction Method for Improvement of Calculation Accuracy of Electromagnetic Force Analysis in Magnetostatic Field Using Nodal Force Method

Calculation of electromagnetic forces are applied to the design of electrical machines, such as the magnetic levitation systems, actuators, and various motors and so on. To accurately pursue the dynamics of electrical machines, the calculation of electromagnetic forces must be accurate. The calculation accuracy of the electromagnetic force using the finite element method is substantially dependent on the configuration of the finite elements. When the analysis model is discretized by the finite element mesh with bilateral symmetry, the accuracy of electromagnetic force tends to be better owing to the offset of the error components by the bilateral meshes. However, the application of an asymmetric finite element mesh affects the accuracy of electromagnetic force. This is because the offset generated by the bilateral meshes is not achieved. Since controlling the mesh distribution with bilateral symmetry has limitations due to the asymmetry of the analysis target, it is effective to estimate the numerical calculation error of the electromagnetic force rather than symmetrical mesh generation. In this study, an estimation method of the error component of the electromagnetic force is proposed and applied to the analysis model in a magnetostatic field problem. Furthermore, the error estimation for a model with the nonlinear magnetic property including an iron core is proposed. The validity of the proposed method is illustrated compared to the conventional nodal force method.