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An EMI‐Optimized Transformer for De‐Y Flyback Converter with Low Common‐Mode Noise
Author(s) -
Wang Tingying,
Shao Chensheng,
Liu Qi,
Liao Liangchuang,
Qian Qinsong,
Ding Desheng
Publication year - 2021
Publication title -
ieej transactions on electrical and electronic engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.254
H-Index - 30
eISSN - 1931-4981
pISSN - 1931-4973
DOI - 10.1002/tee.23409
Subject(s) - flyback transformer , emi , flyback converter , electromagnetic interference , transformer , capacitor , converters , electronic engineering , electrical engineering , common mode signal , engineering , noise (video) , voltage , computer science , digital signal processing , artificial intelligence , analog signal , image (mathematics)
Y‐capacitors are widely used in flyback converters to suppress common‐mode (CM) noise to comply with the strict electromagnetic interference (EMI) standards. However, Y‐capacitors increase the leakage current between the primary and secondary side, which is not allowed in the applications with high safety requirements. In this paper, the displacement current models of two conventional De‐Y methods are quantitatively established to analyze their limitations for the flyback converter. Then, a hybrid EMI‐optimized transformer is proposed to improve the limitations. The proposed structure can completely balance the CM noise between the primary and secondary sides, making the flyback converter comply with the EMI standard under the conditions of no Y‐capacitor. Compared with the traditional methods, the proposed method has a better capability for CM noise suppression, higher universality and the same cost. Finally, the simulation and experimental results verify that the CM noise of the new transformer structure decreases about 10 dB compared with that of the conventional one. © 2021 Institute of Electrical Engineers of Japan. Published by Wiley Periodicals LLC.