The distinctive toroidal core structure and asymmetric winding mode of toroidal high-frequency transformers facilitate the leakage magnetic field distribution characteristics to differ significantly from those of shell and core transformers. Consequently

the conventional method for calculating transformer leakage inductance is limited. This paper introduces a novel analytical approach for determining the leakage inductance of toroidal high-frequency transformers. Analytical expressions for the internal and external magnetic field intensities generated by a round conductor and a surrounding conductor are derived by using the magnetic field energy method and Ampere’s law. Spatial subdivisions are then implemented based on the distribution characteristics of the leakage magnetic field

and the magnetic leakage energy of each sub-region is calculated through independent integration. The impact of eddy current loss on leakage inductance at high frequencies is thoroughly taken into account

and the leakage magnetic energy of irregular gaps between turns is indirectly considered to enhance calculation accuracy. A toroidal transformer prototype is designed and fabricated for experimental validation

demonstrating a relative error of less than 4% between the measured and theoretical values

surpassing traditional calculation methods. To systematically assess the analytical approach

16 sets of simulation verification systems are established

comprising one benchmark group mirroring the prototype’s specifications and 15 derivative groups with core parameters adjusted discretely. The relative deviation between calculated and simulated values is below 5%

verifying the efficacy and accuracy of the proposed method.