Comparison of analytical methods for calculating the AC resistance and leakage inductance of medium-frequency transformers

In this paper, a detailed investigation and comparison of different analytical expressions for the high-frequency resistance of medium-frequency transformers is presented. The comparison is made by 2D FEM simulations and experimental tests with suitable transformers. The deviations between the FEM and the various analytical calculations are presented explicitly via error contour maps to characterize the formulas for different geometrical parameters of common transformers. The comparison shows that the modified Dowell-based method features accurate results. The same study is also done to get an accurate prediction of the desired leakage inductance of transformers by modifying the formula based on Dowell.