A Novel Battery Charger with Fuzzy-Based Taguchi Method

• Main Authors: Chun-Liang Liu, 劉俊良
• Other Authors: Yi-Hua Liu
• Format: Others
• Language: zh-TW
• Published: 2014
• Online Access: http://ndltd.ncl.edu.tw/handle/93771335352908588904

博士 === 國立臺灣科技大學 === 電機工程系 === 102 === Lithium ion (Li-ion) batteries have been widely used in various kinds of applications, including consumer electronics, green energy systems and electrical vehicles. Since the charging method has a significant influence on the performance and lifetime of Li-ion batteries, an intelligent charging algorithm which can properly determine the charging current is essential. In this dissertation, a fuzzy-logic-control-based (FLC-based) five-stage Li-ion battery charger is proposed. The proposed charger takes the temperature rise and the gradient of temperature rise of battery into account, and adjusts the charging current accordingly. Comparing with the conventional constant current-constant voltage (CC-CV) and five-stage CC charging methods, the proposed charger is capable of charging the Li-ion batteries with shorter charging time and higher charging efficiency. To further improve the performance of the proposed FLC, the fuzzy-based Taguchi method is utilized to determine the optimal output membership functions (MFs). The fuzzy-based Taguchi method can be regarded as a multiple performance characteristic index (MPCI) problem and can obtain the optimal output MFs in only 54 experimental tests. Comparing with the conventional CC-CV method, the charging efficiency and the obtained cycle life of the Li-ion battery are increased by 1.65% and 59.3%. The charging time and average temperature rise in the proposed are reduced about 58.3% and 26.7%, respectively.