Magnetic field analysis of coupling transformers for electric vehicle using 3-D finite element method

The 3-D analysis is useful for the optimum design of high frequency coupling transformers which have complex structures. It is difficult to predict the current distributions taking into account eddy currents in sheet coils. In this paper, the current density vector analysis and the magnetic field analysis taking into account eddy currents in the spiral sheet coils are coupled. The exciting current characteristics and copper loss are calculated by our method. It is shown that the load characteristics can be accurately calculated by comparison with measurements. The copper loss distributions taking into account eddy currents in the coils are also shown quantitatively.