锂电池组的均衡控制系统设计

发布时间：2018-07-18 07:20

【摘要】：随着人们环保意识的提高,锂电池以其优越的性能迅速出现在人们生活的方方面面,同时越来越广泛的应用对电池管理系统的要求也越来越高。由于生产工艺的限制及使用环境的影响,电池组中各单体电池的不一致性成为限制锂电池应用的关键因素,因此均衡控制成为电池管理系统研究的一个重点以及难点。本文针对主动均衡系统展开了深入的研究。首先本文分析了已经出现的各种均衡方式,设计了一种分层的均衡拓扑结构。底层基于Buck-Boost电路提出了一种改进的结构,增加了一个均衡桥臂,并且采用耦合电感作为能量转移器件,大大减小了电流的脉动。而顶层采用反激式变压器的结构,使能量可以从单体电池转移到电池组,也可以从电池组转移到单体电池,提高了均衡效率。这种结构也增加了可均衡的单体电池的数量,可用于大功率电池组。其次针对控制策略进行了研究,分析了开路电压与SOC的关系,利用曲线拟合快速得到开路电压,从而使利用开路电压进行均衡控制成为可能。然后分析了模糊控制策略,进行了程序流程图的设计,接下来在Simulink环境下搭建仿真模型,验证设计的正确性。最后在仿真的基础上进行实验平台的搭建,进一步验证该设计的合理性。实验结果表明,本文设计的均衡电路对整个锂电池组的均衡起到了很好的效果,增大了均衡电流,减小了电路损耗,最终使各个单体趋于一致,改善了电池组的性能。
[Abstract]:With the improvement of people's awareness of environmental protection, lithium battery has rapidly appeared in all aspects of people's life because of its superior performance. At the same time, more and more extensive application of the battery management system is also becoming more and more demanding. Due to the limitation of the production process and the influence of the environment, the inconsistency of the individual cells in the battery pack becomes the key factor to restrict the application of lithium battery, so the balance control becomes an important and difficult point in the research of the battery management system. In this paper, the active equalization system is studied deeply. First of all, this paper analyzes the existing equalization methods and designs a hierarchical equilibrium topology. An improved structure based on Buck-Boost circuit is proposed in the bottom layer. An equalization bridge arm is added and the coupling inductor is used as the energy transfer device, which greatly reduces the current pulsation. The structure of flyback transformer in the top layer can transfer energy from the single cell to the battery pack or from the battery pack to the single cell so that the equalization efficiency is improved. This structure also increases the number of balanced single-cell cells that can be used in high-power batteries. Secondly, the control strategy is studied, the relationship between open circuit voltage and SOC is analyzed, and the open circuit voltage is obtained quickly by curve fitting, which makes it possible to use open circuit voltage to equalize control. Then the fuzzy control strategy is analyzed and the program flow chart is designed. Then the simulation model is built in Simulink environment to verify the correctness of the design. Finally, the experiment platform is built on the basis of simulation to further verify the rationality of the design. The experimental results show that the equalization circuit designed in this paper has a good effect on the equalization of the whole lithium battery pack, increases the equalization current, reduces the circuit loss, and finally makes the monomer tend to be consistent, and improves the performance of the battery pack.
【学位授予单位】：河南科技大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TM912

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