An adjustable degrees-of-freedom numerical method for computing the temperature distribution of electrical devices

A novel adjustable degrees-of-freedom numerical method for computing the temperature distribution of electrical devices is presented. The proposed method provides a convenient, accurate and efficient approach to increase/reduce variables and couple/decouple variables. In traditional finite element method (FEM), the electromagnetic field and thermal field need different FEM meshes, which reduce the efficiency and accuracy of the field coupling. Also, the traditional method introduces the inevitable error when the power loss is plotted from Maxwell to Fluent as the different meshes are employed. In this paper, the greatest advantage is that the electromagnetic field and thermal field can be computed using a single mesh with the proposed technology of exploiting different constrained degrees-of-freedom, which decreases the computation time and system complexity. The global domain divided into several sub-domains were utilizing various corresponding functions and also employed to reduce the computational burden when calculating the core loss, copper loss, stray loss and temperature distribution. Numerical examples are reported to showcase the accuracy and effectiveness of the proposed method.