Leakage Inductance Reduction Using the Interleaved Winding Technique in High-Frequency Toroidal Transformers

High leakage inductance in transformers is the main cause of excessive voltage spikes and ringing waveforms in dc-dc converters. Therefore, reducing leakage inductance is important in the design of power electronic devices. This paper provides an analysis of high-frequency leakage inductance in toroidal transformers. The leakage inductance is reduced by implementing an interleaved winding arrangement. Interleaved winding is a winding method in which the primary and secondary windings are positioned side by side in each 1 winding. The leakage magnetic field strength distribution is also analyzed in several winding arrangements using FEA simulation. The effect of leakage inductance on high frequency is also discussed. The frequency effect shows the difference in the magnetic energy leakage curves between conventional and interleaved windings. The results indicate that the interleaved winding technique reduced the leakage inductance from an initial value of 56.03 µH to 0.58 µH, representing a reduction of 98.9%. The high-frequency effects show a 9.01% reduction in the leakage inductance of the interleaved winding arrangement.