A State-of-Charge Estimation for Lithium Iron Phosphate Battery by Using Internal Electromotive Force Method

• Main Authors: Cheng-Lien Chou, 周承練
• Other Authors: 陳建富
• Format: Others
• Language: zh-TW
• Published: 2009
• Online Access: http://ndltd.ncl.edu.tw/handle/12006852657771104071

碩士 === 國立成功大學 === 電機工程學系碩博士班 === 97 === This thesis explores the characteristics of the lithium iron phosphate battery to estimate the state-of-charge (SOC) using internal electromotive force and internal resistance. Traditionally, the internal resistance of batteries can be used to estimate SOC. However, the internal resistance of the battery is varied with aging and thus causing error of estimation. By combining internal electromotive force and internal resistance methods to estimate the SOC of battery, the accuracy of SOC estimation is improved. A non-isolated bidirectional converter is used to charge/discharge the four series-batteries to verify the accuracy of the proposed estimating method. Also, the voltage of the batteries, the current of the batteries and the voltage of the bus are monitored though using RS232 interface.