Abstract:Due to the different temperature gradients and coulomb efficiencies, the remaining capacity between cells will be inconsistencies, which results in the decrease of the capacity of battery pack. In order to improve the performance of battery pack, an equalization control strategy, which is based on t-SOC decision and k-SOC control, is proposed. Moreover, SOC algorithm of battery pack at balanced/unbalanced state is proposed. Finally, the accuracy of SOC estimation has been verified at balanced/unbalanced state. The results indicate that our method can provide effective equalization.
[1] Yuang Shung Lee, Ming Wang Cheng. Intelligent control battery equalization for series connected lithium-ion battery strings[J]. IEEE Transactions on Industrial Electronics, 2005, 52(5): 1297-1307. [2] Andrew C Baughman, Mehdi Ferdowsi. Double- tiered switched-capacitor battery charge equalization technique[J]. IEEE Transactions on Industrial Electro- nics, 2008, 55(6): 2277-2285. [3] Park Hong Sun, Kim Chong Eun, Kim Chol Ho, et al. A modularized charge equalizer for an HEV lithium-ion battery string[J]. IEEE Transactions on Industrial Electronics, 2009, 56(5): 1464-1476. [4] Pablo A Cassani, Sheldon S Williamson. Feasibility analysis of a novel cell equalizer topology for plug-in hybrid electric vehicle energy-storage systems[J]. IEEE Transactions on Vehicular Technology, 2009, 58(8): 3938-3946. [5] Masatoshi Uno, Koji Tanaka. Single-switch cell voltage equalizer using multipacked buck-boost converters operating in discontinuous conduction mode for series- connected energy storage cells[J]. IEEE Transactions on Vehicular Technology, 2011, 60(8): 3635-3645. [6] Lee Yuang Shung, Cheng Guo Tian. Quasi-resonant zero-current-switching bidirectional converter for battery equalization applications[J]. IEEE Transactions on Power Electronics, 2006, 21(5): 1213-1224. [7] Qian Hao, Zhang Jianhui, Lai Jih Sheng(Jason). A high-efficiency grid-tie battery energy storage system [J]. IEEE Transactions on Power Electronics, 2011, 26(3): 886-896. [8] Markus Einhorn, Werner Roessler, Juergen Fleig. Improved performance of serially connected li-ion batteries with active cell balancing in electric vehicles [J]. IEEE Transactions on Vehicular Technology, 2011, 60(6): 2448-2457. [9] Antonio Manenti, Andrea Abba, Alessandro Merati, et al. A new BMS architecture based on cell redundancy [J]. IEEE Transactions on Industrial Electronics, 2011, 58(9): 4314-4322. [10] Markus Einhorn, Wolfgang Guertlschmid, Thomas Blochberger, et al. A current equalization method for serially connected battery cells using a single power converter for each cell[J]. IEEE Transactions on Vehicular Technology, 2011, 60(9): 4227-4237. [11] Lu Languang, Han Xuebing, Li Jianqiu, et al. A review on the key issues for lithium-ion battery management in electric vehicles[J]. Journal of Power Sources, 2013, 226(1): 272-288. [12] Matthieu Dubarry, Nicolas Vuillaume, Bor Yann Liaw. From single cell model to battery pack simulation for Li-ion batteries[J]. Journal of Power Sources, 2009, 186(1): 500-507. [13] Zhang S S, Xu K, Jow T R, The low temperature performance of Li-ion batteries[J]. Journal of Power Sources, 2003, 115(2): 137-140. [14] Matthieu Dubarry, Vojtech Svoboda, Ruey Hwu, et al. Capacity loss in rechargeable lithium cells during cycle life testing: the importance of determining state-of-charge[J]. Journal of Power Sources, 2007, 174(1): 1121-1125. [15] Bergveld H J. Battery management systems: design by modelling[M]. Dordrecht: Kluwer Academic Publi- shers, 2001. [16] Javier Gallardo Lozano, Enrique Romero Cadaval, Isabel Milanes Montero, et al. Battery equalization active methods[J]. Journal of Power Sources, 2014, 246(1): 934-949. [17] Zheng Yuejiu, Ouyang Minggao, Lu Languang, et al. On-line equalization for lithium-ion battery packs based on charging cell voltages: part 1. equalization based on remaining charging capacity estimation[J]. Journal of Power Sources, 2014, 247(1): 676-686.