Accurate Calculation of High-Frequency Transformer Leakage Inductance Based on Dowell’s Model and Analysis of Influencing Factors

The leakage inductance of high-frequency transformers (HFTs) is a critical parameter affecting the performance of power electronic equipment, such as DC-DC converters. During the transformer design phase, by precisely calculating and retaining an appropriate amount of leakage inductance, the independent inductors in the original topology can be replaced, thereby reducing the size of the converter. This paper derives the analytical expression for the magnetic field distribution in the core window, based on Dowell’s one-dimensional model system. A leakage inductance calculation model is established using the square integral of the magnetic field strength. The study investigates the effects of winding spatial distribution and operating frequency on leakage inductance. Finally, the model’s accuracy is verified through experimental measurements, with the results aligning closely with those obtained from the analytical method, and the error falling within a reasonable range.