Efficiency Improvement of LLC Resonant Converter under Light Load

• Main Authors: Che-Yang Su, 蘇哲揚
• Other Authors: 賴炎生
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/7v6g59

碩士 === 國立臺北科技大學 === 電機工程系研究所 === 102 === The objective of this thesis is to design and implement an LLC resonant converter controlled by digital signal processor to give 12V output voltage. Variable switching frequency control is used to regulate the output voltage. The resonant inductor, resonant capacitor cooperate to achieve zero voltage switching and reduce switching losses. In addition, a synchronous rectification technique for LLC resonant converter is used to reduce conduction losses in secondary side and burst mode control is used to reduce the switching loss under light load. The Texas Instruments digital signal processor (DSP), TMS320F28035, is used as the control core for the verification of design and implementation. The design specifications include input voltage of 400V, output voltage of 12V and total power rating of 300W. Simulation and experimental results show that the maximum efficiency is 94.66% and the efficiency can be increased up to 18% under 2% load by burst mode control. These results confirm the design and implementation.