Intelligent Estimation of Residual Capacity of Batteries for Electric Vehicles

• Main Authors: Chia-Hao Tsai, 蔡家豪
• Other Authors: Yee-Pien Yang
• Format: Others
• Language: zh-TW
• Published: 2003
• Online Access: http://ndltd.ncl.edu.tw/handle/89832696720329844302

碩士 === 國立臺灣大學 === 機械工程學研究所 === 91 === This research proposes an intelligent method for estimating the residual capacity of lead-acid batteries in electric vehicles. It solves the vital problem when applying the ampere-hour (AH) on the commercial product. To make ampere-hour(AH) more practical and complete, this estimation method discusses three points: (1) the unknown capacity when first using lead-acid batteries; (2) the decrease of capacity when high discharge rate happens; (3) the reset for altering parameters when batteries become deteriorating. This paper provides the following solutions: (1) to estimate real open circuit voltage(OCV) with transient open circuit voltage(TOCV); (2) to put correction function into ampere-hour (AH) for calculating the decrease of capacity; and (3) record the last residual capacity of batteries the first open circuit voltage to reset the original parameters. The experiment results show that the ampere-hour (AH) and TOCV are consatisfactory when transient high-rate discharge happens. The residual capacity can be calculated authentically by adding more correction functions. However, a tremendous error of initial capacity occurs unexpectedly when the TOCV is applied at the end of discharge. It is not preper to use after the residual capacity is less the 50%. Besides, with the record of the last residual capacity and the first open circuit voltage, the linear relationship between the state of charge and the open curcuit voltage is revised to describe the battery deterioration.