Design and Implement of a Digitally Controlled LLC Resonant Converter

• Main Authors: WEI-JIE LI, 李偉傑
• Other Authors: Yi-Hua Liu
• Format: Others
• Language: zh-TW
• Published: 2015
• Online Access: http://ndltd.ncl.edu.tw/handle/03869422580354885739

碩士 === 國立臺灣科技大學 === 電機工程系 === 103 === Resonant converters can reduce switching losses and allow for high-frequency operation, these techniques process power in a sinusoidal manner and achieves zero voltage switching (ZVS). Therefore, the switching losses and noises can be dramatically reduced. Among resonant converters, LLC resonant converter has advantages such as regulating the output voltage over wide line and load variations with a relatively small variation of switching frequency, and achieving ZVS over the entire operating range. In this thesis, a 500 W digitally-controlled LLC resonant converter is implemented and studied. The gating signals of the power switches are generated using a low cost digital signal controller dsPIC33FJ16GS502 from Microchip corp. Detailed description about the hardware and firmware parts of the system will be presented first and the design considerations will be discussed. Next, the losses analysis will be performed, and the effect of the dead time values on the converter efficiency will also be investigated. According to the experimental results, the proposed digitally-controlled LLC resonant converter can achieve efficiencies higher than 90 % under all load conditions.