Common Mode Noise Reduction for an LLC Resonant Converter by Using Passive Noise Cancellation

Ryu, Younggon; Kim, Sungnam; Jeong, Geunseok; Park, Jaesu; Kim, Duil; Park, Jongwook; Kim, Jingook; Han, Ki Jin

doi:2015.15.2.89

J. Electromagn. Eng. Sci > Volume 15(2); 2015 > Article

Journal of Electromagnetic Engineering and Science 2015;15(2):89-96.
DOI: https://doi.org/10.5515/JKIEES.2015.15.2.89

Common Mode Noise Reduction for an LLC Resonant Converter by Using Passive Noise Cancellation

Younggon Ryu¹, Sungnam Kim², Geunseok Jeong², Jaesu Park², Duil Kim², Jongwook Park², Jingook Kim¹, Ki Jin Han¹

¹School of Electrical and Computer Engineering, Ulsan National Institute of Science and Technology
²LG Electronics

Abstract

This paper describes the application of a passive noise cancellation method to a prototype inductor-inductor-capacitor (LLC) resonant converter by placing a compensation winding in a transformer to reduce common mode noise. The connection method for the compensation winding is investigated. A circuit analysis is implemented for the displacement currents between the primary and secondary windings in the transformer. The analyzed displacement currents are verified by performing a circuit simulation and a proper compensation winding connection that reduces common mode noise is found. The measurement results show that common mode noise is reduced effectively up to 20 dB in the 1 to 7 MHz frequency region for the prototype LLC resonant converter by using the proposed passive noise cancellation method.

Key words: Common Mode Noise, Electromagnetic Compatibility, LLC Resonant Converter, Passive Noise Cancellation