Research on the Design Method of Nanocrystalline High-Frequency Transformer

With the rapid development of wide bandgap semiconductors, high-frequency transformers have become vital for enhancing power density: their losses, volume, and parasitic parameters impact system performance. Nanocrystalline magnetic cores offer high saturation magnetic induction and low loss advantages, making them popular in high-frequency transformer design. This study first analyzes the impact of square wave excitation voltage waveform on the core loss model of high-frequency transformers, presenting a revised model. A precise design method for leakage inductance under a hybrid winding is proposed to address the low accuracy in leakage inductance calculation, offering greater freedom in transformer winding design. To summarize the optimization design process of transformers, a 100kHz/7.5kW nanocrystalline high-frequency transformer is designed. A testing platform is built, and test results verify the correctness of the design method: leakage inductance is within 1% of theoretical calculations, and losses are within 6%. This validates the effectiveness of the high-frequency transformer design approach.