Influence of Interleaving Winding Arrangement on Leakage Inductance and Winding Loss of High-frequency Transformer

摘要

Primary and secondary interleaving is normally used to minimize the leakage inductance and winding losses in high-frequency (HF) transformers used in high-power isolated dc-dc converters. Higher switching frequencies lead to the skin and proximity effects more significant, further more, the reduction of leakage inductance and the increase of winding losses. After analyzing the nonlinear distributions of the magnetic field strength and current density along the conductor thickness at high frequency, this paper presents a novel analytical calculation method considering the strong frequency dependence of transformer parameters, which is suitable for the non-interleaving, partially-interleaving, and fully-interleaving winding arrangements. A 4.5kHz, 5kVA HF transformer test model with amorphous core is built, and finite-element method (FEM) simulation and measurement are carried out to verify the method.