Optimization Design of Planar Transformer for High Frequency LLC Series Resonant Converters

• Main Authors: Meng-Fan Lin, 林孟帆
• Other Authors: Huang-Jen Chiu
• Format: Others
• Language: zh-TW
• Published: 2018
• Online Access: http://ndltd.ncl.edu.tw/handle/u9m6cr

碩士 === 國立臺灣科技大學 === 電子工程系 === 106 === Magnetic components are the main source of power losses in high step-down LLC resonant converters. Therefore, to achieve high efficiency and high power density, improving the magnetic element is an important issue. Ferrite cores with high permeability and low core loss are widely used in high-frequency switching power supplies. The core loss mainly results from hysteresis loss and eddy current loss. Therefore, this thesis aims to analyze and optimize the structure of ferrite cores using Maxwell software to implement the Finite Element Method (FEM). Changing the distribution of magnetic flux density to reduce core loss results in a tradeoff design between the volume and loss of magnetic core. Then, the transformer can be optimized to achieve high circuit efficiency. Finally, a 750-W LLC resonant converter prototype with specifications of 380-V input voltage, 12-V output voltage, and 500-kHz switching frequency is implemented and tested to verify the feasibility of different architectures on transformer cores.