鋰電池充電之最佳化研究

Abstract

隨著可攜式電子產品的成長，例如手機、筆記型電腦和個人數位助理器等，使得鋰電池在電源管理扮演非常重要的角色，如何有效提高充電效率及縮短充電時間，得到較高的鋰電池充電效能變得非常重要。目前市面鋰電池充電主要採用定電流-定電壓方法，但是以此方法將鋰電池充滿需要很冗長的充電時間。本文提出鋰電池充電最佳化的方法，有別於傳統的定電流-定電壓充電模式，將充電過程畫分成多段來考量，透過整數線性規劃決定每一段的充電電流值，再將每一段充電電流合成為整個鋰電池的充電輪廓，可以依據電路設計者對效能的需求提出一套最佳化鋰電池充電配方。以此方法規畫出來的最佳化充電配方分別以快速和慢速定電流-定電壓充電方法做比較，經由實驗發現的確有效縮短充電時間分別為18% 和21%。

Commercial lithium batteries play an important role as power supplies for mobile phones, laptops, personal digital assistants (PDA) and other electronic devices. In order to maximize the performance of lithium batteries, a higher charging efficiency and less charging time are required. Today, the main charging method for lithium batteries is the constant current-constant voltage method (CC-CV), but its lengthy charging time poses a problem. This thesis presents a method to search optimal charging profile for batteries. Using such method, the charging profile is dramatically improved from the general constant current-constant voltage method. The charging process is divided into multistage for scheduling. Integer linear programming (ILP) is used to determine the value of current for each stage; all stages are then combined to synthesize the optimal charging profile for lithium batteries. Using the proposed programming, the charging profile obtained result in a charging time span which is 18% shorter than that provided by the fast constant current-constant voltage method. Likewise, the charging time of the new charging profile improve 21% over the slow constant current-constant voltage method.