Design and Implementation of a igitally-Controlled Phase-Shift Full-Bridge onverter for Battery Charger

• Main Authors: Shih-Cin Ji, 紀仕秦
• Other Authors: Yi-Hwa Liu
• Format: Others
• Language: zh-TW
• Published: 2011
• Online Access: http://ndltd.ncl.edu.tw/handle/dg33z2

碩士 === 國立臺灣科技大學 === 電機工程系 === 99 === Lead-acid batteries are commonly utilized in electrical vehicles. For lead-acid batteries, an intelligent battery charger is essential for maximizing the charging efficiency and prolonging the battery cycle life. In this thesis, a fully-digital battery charger based on a phase-shift-controlled full-bridge converter (PSFBC) is presented. Full-bridge converters with phase-shift switching control have been widely employed in medium-power or high-power applications. These converters provide zero-voltage switching (ZVS) for the power devices of the full bridge converter. The switching loss can, therefore, be significantly reduced. The digital controller including the digital PID compensator and digital filter is designed and implemented. Analog controllers are replaced by a single dsPIC33FJ16GS502 digital signal controller (DSC) from Microchip Corp. The advantages of the digital controller include components cost reduction and more flexible design. Digital power stage also provides intelligent adaptability and flexibility to satisfy any complex power requirement with the straightforward ability to monitor, process and adapt to system conditions. In addition to provide the digital control of the PSFBC, a five-step constant-current charging algorithm is also implemented. The five-step constant-current charging algorithm is proven to have the advantages such as longer cycle life, higher charge/discharge energy efficiency and shorter charging time. Moreover, this method can easily be incorporated into ICs because its simplicity. In order to verify the correctness of the proposed system, experimental results will be given to validate the correctness of the proposed system and the measured efficiency of the whole system achieved 92%.