現今電動車及儲能系統快速發展，使鋰離子電池產量與需求大幅提升，因而帶動鋰離子電池回收市場發展，若能將電動車汰換下來的電池使用於儲能系統做二次使用，能延緩電池被回收的時間，並使儲能設備建置上的成本大幅降低。但各個汰役電池之電池健康狀態並不一致，若直接提供給負載做使用，會導致電池彼此間的差異愈來愈大，進而影響到電池電量利用率。
因此本文研製一雙向直流轉直流降/升壓平衡電路，並提出容量平衡及電壓平衡控制策略，依據不同的電池健康狀態來調整每個電池的充放電速率，在充放電過程中讓每顆電池容量或電壓趨近，使電池能發揮更高之充放電利用率。
本文測試兩種不同實驗情境：第一種為兩顆電池之電池健康狀態相同，但電池相對電量狀態不同;第二種為兩顆電池健康狀態不同，但電池相對電量狀態相同。由實驗結果可得知，在第一種情境下，容量平衡法相較於電壓平衡法，放電節省24.8%之平衡時間，充電節省56.6%之平衡時間。而容量平衡法及電壓平衡法相較於無平衡，放電延長12.9%及10%之放電時間，充電增加19.1%及19.2%之充電容量;在第二種情境下，容量平衡法相較於電壓平衡法，放電節省41.9%之平衡時間，充電節省63.4%之平衡時間，而容量平衡法及電壓平衡法相較於無平衡，放電延長19.4%及15.1%之放電時間，充電增加21.7%及18.7%之充電容量。

Nowadays, the rapid development of electric vehicles and energy storage systems has greatly increased the production and demand for lithium-ion batteries, thus driving the development of the lithium-ion battery recycling market. If the batteries replaced by electric vehicles can be utilized for secondary use in the energy storage system, the time for battery recycling can be delayed, and the cost of energy storage equipment construction can be greatly reduced. However, the battery health status of each retired battery is not consistent. If it is directly supplied to the load for use, the difference between the batteries will increase gradually, which will affect the battery’s power utilization rate.
Therefore, this thesis develops a bidirectional DC-to-DC buck/boost balancing circuit and proposes a capacity balance and voltage balance control strategy to adjust the charge and discharge rate of each battery according to different battery health states. In the process of charging and discharging, the capacity or voltage of each battery will approach each other, so that the battery can offer a higher energy utilization.
Through the two experimental scenarios in this thesis, the first is that the two batteries have the same battery state-of-health (SOH), but the battery relative state-of-charge (RSOC) is different; the second is that the two batteries have different SOH, but the RSOC of the battery is the same. The experimental results can be obtained, for the first scenario, compared with the voltage balance method, the capacity balance method saves 24.8% of the balancing time for discharging and 56.6% of the balancing time for charging. Compared with the unbalanced method, the capacity balance method and the voltage balance method prolong the discharge time by 12.9% and 10.0%, and increase the charging capacity by 19.1% and 19.2%. For the second scenario, the capacity balance method saves 41.9% of the balancing time for discharging and 63.4% of the balancing time for charging when compared with the voltage balance method. Compared with the unbalanced method, the capacity balance method and the voltage balance method prolong the discharge time by 19.4% and 15.1%, and increase the charging capacity by 21.7% and 18.7%.

[1] 科技政策研究與資訊中心，美國2021-2030年國家鋰電池藍圖與鋰電池回收技術(2021年08月11日)。檢自https://outlook.stpi.narl.org.tw/index/focus-theme/detail?id=4b114100791e3859017b90c2e6e44e5a/ (Dec. 6th, 2021)
[2] 謝騄璘、蔡宜君、呂學隆，「全球電動車市場動向與48V微混系統鋰電池商機剖析」，工業技術研究院，2020年4月21日。
[3] P. T. Krein and R.S. Balog, “Life Extension Through Charge Equalization of Lead-Acid Batteries,” in Proceedings of the 24th Annual International Telecommunications Energy Conference (INTELEC), pp. 516-523, Sep./Oct. 2002.
[4] S. West and P. T. Krein, “Equalization of Valve-Regulated Lead-Acid Batteries: Issues and Life Test Result,” in Proceedings of the 22nd International Telecommunications Energy Conference, pp.439-446, Sep. 2000.
[5] N. H. Kutkut, H. L. N. Wiegman, D. M. Divan and D. W. Novotny, “Design Considerations for Charge Equalization of an Electric Vehicle Battery System,” IEEE Symposium on Industrial Electronics and Applications, Vol. 35, No. 1, pp. 28-35, Jan./Feb. 1999.
[6] S. Hong, J. Jiang and X. Li, “A battery management system with two-stage equalization,” in 29th Chinese Control and Decision Conference, 2017.
[7] H. Oman, “Making Batteries Last Longer,” IEEE Aerospace &Electrics Systems Magazine, Vol. 14, No. 9, pp. 19-21, 1999.
[8] L. Lu, X. Han, J. Li, J. Hua and M. Ouyang, “A review on the key issues for lithium-ion battery management in electric vehicles,” Journal of Power Sources, Vol. 226, pp. 272-288, Mar. 2013.
[9] B. S. Sagar, B. P. Divakar and K. S. V. Prasad, “Series battery equalization using sequential difference algorithm,” Advances in Electronics, Computers and Communications (ICAECC), 2014 International Conference, pp.1-6, 2014.
[10] T. A. Stuart and W. Zhu, “Modularized battery management for large lithium ion cells,” Journal of Power Sources, Vol.196, No.1, pp.458-464, 2011.
[11] Y. Lee, S. Jeon and S. Bae, “Comparison on Cell Balancing Methods for Energy Storage Applications,” ResearchGate , vol.9, May. 2016.
[12] W. Luo, L. Jie, W. Song and Z. Feng, “Study on passive balancing characteristics of serially connected lithium-ion battery string,” in 13th International Conference on Electronic Measurement & Instruments, 2017.
[13] J. G. Lozano, E. R. Cadaval, M. I. M. Montero and M. A. G.Martinez, “A novel active battery equalization control with on-line unhealthy cell detection and cell change decision,” Journal of Power Sources, Vol.299, pp.356-370, 2015.
[14] P. A. Cassani and S. S. Williamson, “Design, Testing, and Validation of a Simplified Control Scheme for a Novel Plug-In Hybrid Electric Vehicle Battery Cell Equalizer,” IEEE Transactions on Industrial Electronics, Vol. 57, No. 12, pp. 3956-3962, Dec. 2010.
[15] W. C. Lee and D. Drury, “Development of a Hardware-in-the-Loop Simulation System for Testing Cell Balancing Circuits,” IEEE Transactions on Power Electronics, Vol. 28, No. 12, pp. 5949-5959, Dec. 2013.
[16] D. D. Quinn and T. T. Hartley, “Design of novel charge balancing networks in battery packs,” Journal of Power Sources, vol.240, pp.26-32, 2014.
[17] M. Daowd, N. Omar, P. V. D. Bossche and J. V. Mierlo, “Passive and Active Battery Balancing Comparison Based on MATLAB Simulation” in Proceeding IEEE Vehicle Power Propul. Conference, pp.1-7, 2011.
[18] Y. Ye and K. W. E. Cheng, “An Automatic Switched-Capacitor Cell Balancing Circuit for Series-Connected Battery Strings,” Energies, vol.9, no.3, pp.1-15, Feb. 2016.
[19] C. Speltino, A. Stefanopoulou, G. Fiengo, “Cell equalization in battery stacks through State Of Charge estimation polling” Proceedings of the 2010 American Control Conference, 2010
[20] D. H. Zhang, G. R. Zhu, S. J. He, S. Qiu, Y. Ma, Q. M. Wu and W. Chen, “Balancing Control Strategy for Li-Ion Batteries String Based on Dynamic Balanced Point,” Energies, Vol. 8, No. 3, pp. 1830-1847, Mar. 2015.pp.4906-4913, 2015.
[21] J. Xu, S. Li, C. Mi, Z. Chen and B. Cao, “SOC Based Battery Cell Balancing with a Novel Topology and Reduced Component Count,” Energies,Vol.6, No.6, pp.2726-2740, 2013.
[22] B. Dong, Y. Li and Y. Han, “Parallel Architecture for Battery Charge Equalization,” IEEE Transactions on Power Electronics, Vol.30, No.9, pp.4906-4913, 2015.
[23] Y. S. Lee and G. T. Chen, “ZCS bi-directional DC-to-DC converter application in battery equalization for electric vehicles,” IEEE Journal of Emerging and Selected Topics in Power Electronics, vol.4, pp.2766-2772, 2004.
[24] S. H. Park, T. S. Kim, J. S. Park, G. W. Moon and M. J. Yoon, “A new battery equalizer based on buck-boost topology,” IEEE 7th International Conference on Power Electronics, pp.962-965, 2007.
[25] W. Ji, X. Lu, Y. Ji, Y. Tang, F. Ran and F. Z. Peng, “Low cost battery equalizer using buck-boost and series LC converter with synchronous phase-shift control” in 2013 Twenty-Eighth Annual IEEE Applied Power Electronics Conference and Exposition, pp.1152-1157, 2013.
[26] J. Yan, Z. Cheng, G. Xu, H. Qian and Y. Xu, “Fuzzy Control for Battery Equalization Based on State of Charge” Vehicular Technology Conference Fall (VTC 2010-Fall), pp.1-7, 2010.
[27] W. Huang and J. A Qahouq, “Energy Sharing Control Scheme for State-of-Charge Balancing of Distributed Battery Energy Storage System” IEEE Transactions on Industrial Electronics, vol.62, pp.2764-2776, 2014.
[28] Y. Cao and J. A Qahouq, “Hierarchical SOC Balancing Controller for Battery Energy Storage System” IEEE Transactions on Industrial Electronics, vol.68, pp.9386-9397, 2020.
[29] Y. D Yang, K. Y Hu and C. H Tsai, “Digital Battery Management Design for Point-of-Load Applications With Cell Balancing” IEEE Transactions on Industrial Electronics, vol.67, pp.6365-6375, 2019.
[30] J. A Qahouq, L Zhang, Y Cao and B Balasubramanian, “DC-DC power converter controller for SOC balancing of paralleled battery system” 2016 IEEE Applied Power Electronics Conference and Exposition (APEC), 2016.
[31] Y. Cao and J. A Qahouq, “Evaluation of paralleled battery system with SOC balancing and battery impedance magnitude measurement” 2018 IEEE Applied Power Electronics Conference and Exposition (APEC), 2018.
[32] 孫清華，「最新可充式電池技術大全」，全華科技圖書，民國九十二年九月。
[33] 李世興，「電池活用手冊」，全華科技圖書，民國八十五年一月。
[34] 屠海令，「先進電池：電化學電源導論」，冶金工業出版社，民國九十五年五月。
[35] 立錡科技，鋰離子電池及電池電量計介紹。檢自https://www.richtek.com/Design%20Support/Technical%20Document/AN024?sc_lang=zh-TW/ (Jun. 6th, 2021)
[36] Z. Xia and J. A Qahouq, “State-of-Charge Balancing of Lithium-Ion Batteries With State-of-Health Awareness Capability” IEEE Transactions on Industry Applications, vol.57, pp.673-684, 2020.
[37] 鄭偉呈，「基於類神經網路之鋰離子電池健康狀態估測技術研究」，國立台灣科技大學電機工程所碩士學位論文，民國一百一十年七月。
[38] 吳義利，「切換式電源轉換器」，文笙書局，民國一百零九年。
[39] 呂文隆、張簡士琨、曾國境，「交換式電源設計」，全華科技圖書，2012。
[40] PSIM User's Guide, Powersim Inc., 2003.
[41] Panasonic Inc., “Lithium Ion Battery-NCR18650” Specification of product, ver. 13.11 R1, 2012.
[42] Samsung Inc., “Lithium Ion Battery-ICR18650-26J” Specification of product, ver. 2.0, 2016.
[43] 王順忠，「電力電子學」，臺灣東華書局股份有限公司，民國90年。
[44] 廖柏涵，「以剩餘容量為基礎之鋰離子電池平衡電路」，國立台灣科技大學電機工程所碩士學位論文，民國一百零七年一月。
[45] 林韋盛，「可縮短平衡時間之鋰離子電池組平衡器」，國立台灣科技大學電機工程所碩士學位論文，民國一百零八年六月。
[46] 李昱伸，「鋰電池主動式平衡器研製」，國立台灣科技大學電機工程所碩士學位論文，民國一百一十年一月。