| Title |
Common-Mode noise Reduction Using a Parasitic-Capacitance-Adjustable Bobbin with an Impedance-Balancing Structure |
| Authors |
윤예빈(Ye-Bin Yoon) ; 서현우(Hyun-Woo Hyun) ; 차명준(Myung-Jun Cha) ; 김래영(Rae-Young Kim) |
| DOI |
https://doi.org/10.5370/KIEE.2026.75.9.2107 |
| Keywords |
CM noise; EPC-Adjustable bobbin structure; Impedance balancing; Wheatstone bridge modeling; High-frequency noise suppression |
| Abstract |
This paper presents a novel common-mode(CM) choke structure that achieves impedance balancing by controlling Equivalent Parallel Capacitance(EPC) through an adjustable bobbin design. High-speed power converters generate significant high-frequency CM noise during rapid switching, requiring effective suppression for Electromagnetic Compatibility(EMC) and reliability. While conventional CM filters can attenuate CM noise, their high-frequency performance is strongly affected by the EPC of the inductors and tolerances of Y-capacitors. To address this limitation, a bobbin structure is proposed that enables precise adjustment of the inter-winding distance, thereby allowing control of the EPC without additional passive components. The proposed structure satisfies the Wheatstone bridge-based impedance balancing condition. The validation is performed using a 3.7 kW resonant inverter system, demonstrating up to 9.3 dBμV of CM noise reduction in the 1 MHz to 5 MHz frequency band. |