以DSP微控制器實現可程式鋰電池主動式平衡與管理系統

DSP-Based Programmable for Active Equalization Circuit and Management System of Lithium Battery

吳建明(Jian-Ming Wu)

指導教授 ： 劉煥彩

國立虎尾科技大學/電機資訊學院/電機工程研究所在職專班/碩士(2013年)

摘要

本論文之研究主軸為改良「二階層主動式平衡」之鋰電池串聯電路平衡，並設計驗證其功能性。平衡電路針對四串之鋰電池提供各電池串之電壓監控，當偵測到各串電池間電量出現不平衡情形，透過二階層式電量平衡技術，使用Buck-Boost Converter之原理，將電量較高之電池串電壓升壓，再將升壓後之電荷移至鄰近之電池串上，達到平衡之作用。
目前有許多主動式平衡研究多以TI製造的專用IC及平衡電路設計，該技術是由鄰近的電池能量相互比較，將能量較高的電池能量儲存於電感上，經由電感轉換電荷到鄰近電池上。鄰近電池相互比較的缺點在於電池組中，能量儲存於電感上時，電感能量會有些許下降，當電池數目越多，所需的電感數目越多、比較的次數也越多，電感數目越多，相形之下的電路也越複雜。而每次的比較轉換都是能量的損失，當比較次數增加，相對的轉換損失也就越大。本研究提出一改良型的電池平衡電路，平衡方式由電池組中能量最高之電池串，將其能量升壓儲存於電感上，透過開關切換再將升壓後之能量轉換到能量較低的電池串上，其優點在於，只需一個電感，大大簡化了電路的複雜性，且能量的轉換是由最高壓電池與最低壓電池先進行平衡，減小電池組各電池串間的能量差異，縮減比較次數，從而降低轉換時的能量損失。

關鍵字

鋰電池 ； 降升壓轉換器 ； 升壓轉換器 ； 主動式平衡 ； 串聯電池組

並列摘要

The purpose of this thesis is to modify the “Dual order active equalization circuit” which is proposed in the reference for lithium-ion battery. The active equalization circuit is designed for manage a 4-series-cell battery system; provide a voltage monitoring for each cell. When microcontroller detected an unbalancing condition exists between cells, A Dual Oder technology based on Buck-Boost converter principle is used for cell balancing. The Buck-Boost converter boosted the voltage of the highest cell to an inductor via switching the frequency, and transfers charges to other lower voltage cells to achieve the series-connected battery cell balancing.
Many researching of active equalization circuits are designed based on dedicated chip of Texas Instrument. This technology implemented cell balancing by comparing the cells which are neighboring. Stored charges from higher voltage cell to inductors, and transferred energy to the lower voltage cell via inductors. The weaknesses of this technology are complex circuits and energy wasting. The energy will be reduced while stored in the inductor. The more cells increased the more inductor increasing. The more inductors increased the more energy depletion will be, also complicated the circuits.
This thesis is proposed a modified efficiency of equalization circuit. The balancing method is transfers energy from highest voltage cell to inductor, share charges to lowest voltage cells by MOS switching. The strength is just only one inductor is needed, simplified the circuits as well. Energy transferred from highest voltage cell to lowest voltage cell before balancing, reduced voltage difference between cells and comparing time, thus reduced energy depletion during transferring.

並列關鍵字

Lithium Battery ； Buck-Boost Converter ； Boost Converter ； Active Battery Equalization ； Series-connected Batteries

參考文獻

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Converters, Applications and Design, 2nd, John Wiley & Sons Inc.

plus charger using hybrid buck-boost converter,” Power Electronics and Drive Systems, 4th IEEE International on , October.

[12] AccuValer and et al., 2008, Battery Management System : Accurate State-of-Charge

Indication for Battery-Powered Applications, Springer, New York.