Fast Inductance Extraction for Sweeping Coil Positions Based on Nonconforming Finite Element Method and Dual Formulations

Computing inductance parameters of electromagnetic devices for different coil positions and angles is a practical problem commonly encountered. Typical applications include finding the mutual inductances for different relative positions of the coils of a wireless power transfer system. Due to a lot of sample relative positions of the coils need to be swept, it is really a time-consuming process for obtaining all the inductance values for each position. In this paper, firstly new efficient dual formulations are proposed where the global finite element matrices are totally the same thus the global assembly process needs to be performed once, which is also the case for the factorization when using sparse direct solvers. When sweeping different position parameters of the coils after translation or rotation, a sliding mesh technique is adopted to greatly save the CPU time to avoid regenerating different finite element meshes. Two test cases are illustrated using the proposed dual formulations and remesh-free nonconforming finite element method, a great acceleration can be achieved and the computed inductance parameters are also accurate.