Study on EMI noise reduction for high-frequency resonant converter

Abstract

In this dissertation, a new structure of transformer and its winding layout are proposed to reduce the common mode (CM) noise generated from the planar transformer (PT). By utilizing static-point-connected transformer and balanced resonant tank, proposed two half-bridge and full-bridge converters can reduce the CM current flowing through parasitic capacitors of the transformer. Moreover, the CM noise can be significantly reduced by adjacently locating primary and secondary layers with the same dv/dt characteristic. As a result, Proposed converters can achieve a high power density by reducing the size of EMI filter. Also, proposed converters can be utilized for the medium-to-high power applications due to the high voltage gain and small primary current of two half-bridge and full-bridge structure. Consequently, the proposed converter can improve the power density of the converter for the medium-to-high power applications such as electric vehicle system.