預估動態變化之鋰電池模擬技術

Abstract

本論文的目的是提出一種模擬電池放電技術，此技術能有效預估鋰電池在動態負載下的放電行為，提供電路設計者在設計電路時，藉由此技術模擬電池對系統供電時的參考。模擬技術的建構，係利用簡化鋰電池等效電路作為電池模型，透過實驗量測電池在不同的電量狀態(SoC)下模型內部等效參數：電池電動勢(EMF)以及過電壓內電阻(Rop)，並且將取得的參數關係建立查找表作為模擬使用。模擬鋰電池放電過程中，對設定之負載電流積分，並且引入擴散法分析模型[1]來估測電池的初始電容量與運行時間，取得電池在此負載電流下的電量狀態(SoC)，藉由找查表轉換出與之相對應的EMF及Rop，並且計算出鋰電池在特定電量狀態下的電池端電壓作為模擬放電時的參考。最後利用多組動態負載進行驗證，從實驗結果發現，此技術能夠模仿電池在動態負載下的放電行為以及準確估測電池的運行時間。

The thesis aims to present a battery technology can imitate behavior of discharge. This technology can estimate the behavior of discharge of battery under any kind of dynamic loading profile. So the circuit designers can use it to be a reference of system power source. It is built on the simplify circuit as a battery model. Through the model’s parameters, EMF and Rop, are measured from the experiment under different state of charge. This result will be built a lookup table to be simulation. When simulation process is operating, the product of current and time of operation has to be accumulated, then the Diffusion model will be used to estimate the initial capacity and life-time, and therefore the state of charge under this profile will be obtained. According to the result to find out the EMF and Rop from lookup table, and calculate the battery terminal voltage under particular state of charge to be a reference of simulation. Finally we use a series of dynamic loading profiles to validate this technology, this technology can imitate the behavior of discharge under any kind of dynamic loadings and estimate the operation time accurately from the experiment result.