Gaussian-Polynomial Temperature Model for the Discharge Behavior of a Lithium-Ion Battery

鋰電池放電行為的高斯－多項式溫度模型

翁志祁(Che-Chi Weng) ； 逄霖生(Lin-Sen Pon)

《華岡工程學報》 21期 (2007/06) Pp. 121-127

https://doi.org/10.29987/CCUHKJE.200706.0018

摘要

本研究延續高斯多項式的近似模型，將電池的工作溫度做為參數。我們用一個四次方的溫度的多項式函數來描述鋰電池在固定負載，但不同操作溫度下的非線性的放電行為。在電池剩餘容量百分比與電池電壓的函數圖中，實際的量測值與本模型的誤差大多發生在電池放電的初期，然而在電池放電的中段及末端，本模型則有非常優異的表現，其電壓誤差都在零點一伏特以內。若以剩餘電池容量的百分比來計量，其誤差則在三個百分點以內。對於使用者而言，他們在乎的是，還剩多少電池容量可供使用，而非已使用了多少電量。所以，對於電池放電後段行為的瞭解，遠比放電前段的描述更為重要。雖然高次方的多項式看起來奇特而複雜，但在日漸普遍的以微處理機來實現剩餘電量的預測下，這並不會造成任何困擾。

關鍵字

鋰電池 ； 可充電電池 ； 電池剩餘容量 ； 放電曲線 ； 高斯函數 ； 多項式函數 ； 電池放電行為 ； 高斯－多項式近似模型 ； 高斯－多項式溫度模型

並列摘要

In this research, we extend the Gaussian-Polynomial Approximation Model with operation temperature as the parameter. A fourth-order temperature polynomial is used to describe the nonlinear feature of batteries discharge behavior for a fix current load under various temperatures. As a result, in the curve of percentage of remain capacity versus voltage, the major differences between the observed discharge curve and the curve generated from our temperature model is happened only in the beginning of the discharge. In the middle and the later part of the discharging, our model fits very well to the observed discharge curve. The differences are within 0.1 volts. As to the percentage of remaining battery capacity, the differences are within 3 percents. To the users, the important concern is how much the capacity remains to be used, rather than how much capacity they have used. Thus, the understanding of the later part of the discharge curve is much more important than that of the earlier part. Although the high order polynomial looks odd and complicated, the getting more popular microprocessor implementation of fuel gauge doesn’t seem to be a problem.

並列關鍵字

Lithium-ion battery ； Rechargeable battery ； Polynomial ； Gaussian ； Gaussian-polynomial approximation model ； Gaussian-polynomial temperature model ； Battery discharge behavior