Modeling and Analysis of Near‐Field Radiation From High‐Frequency Transformers in Flyback Converters Based on Poynting's Theorem

ABSTRACT Electromagnetic compatibility is a critical factor in high‐frequency transformer design. Research typically focuses on reducing electromagnetic radiation from flyback transformers in switching power supplies by suppressing common‐mode currents and employing common‐mode filters. However, the influence of a high‐frequency transformer's three‐dimensional structure and materials on radiation is difficult to assess directly. To address this, this paper models and analyzes a flyback high‐frequency transformer to overcome the limitations of traditional common‐mode current‐centric research methods. By modeling the flyback high‐frequency transformer in Maxwell software and simulating the distribution of electromagnetic fields and flux within its three‐dimensional structure, this study effectively evaluates the influence of the transformer's three‐dimensional structure and materials on near‐field radiation. Experimental validation of the analysis results demonstrates that the proposed method can effectively assess the impact of structural parameters on near‐field radiation, providing a research foundation for machine learning‐based EMI optimization design.