Accurate magnetic field calculations for contactless energy transfer coils

In this paper, a method for estimating the magnetic field intensity from hexagon spiral windings commonly found in contactless energy transfer applications is presented. The hexagonal structures are modeled in a magneto-static environment using Biot-Savart current stick vectors. The accuracy of the models are evaluated by mapping the current sticks and the hexagon spiral winding tracks to a local twodimensional plane, and comparing their two-dimensional magnetic field intensities. The accuracy of the magnetic field intensity calculations can then be improved by employing the mesh matrix method. To demonstrate the presented method, the magnetic field intensity distribution of a hexagon spiral winding is calculated using single filament substitution and compared with the mesh matrix-based improved current filament model. Distinct differences between the two distributions are noted, which confirms the need and advantages of using the model presented in this paper, especially when highly accurate results are required