纯电动汽车锂动力电池组双向均衡控制策略研究及系统开发

发布时间：2018-01-26 10:49

本文关键词： 锂动力电池电池不一致性双向均衡反激式变压器　出处：《吉林大学》2014年硕士论文　论文类型：学位论文

【摘要】：由于电池单体间不一致性的存在，当单体锂动力电池经过串并联应用于纯电动汽车后，性能较差的电池较早的达到充放电截止电压造成电池组的容量利用率下降，降低纯电动汽车续驶里程，增加纯电动汽车使用成本，不利于纯电动汽车的使用与推广。本文所研究的均衡技术通过实时监测电池组在使用过程中的状态信息来对电池组进行均衡管理，能改善电池组使用过程中的不一致性产生的影响，提高电池组的容量利用率，减缓电池老化速度，延长电池组的使用寿命，增加电动汽车续驶里程。本文以对锂动力电池组不一致性的机理分析为基础，设计均衡系统，并完成系统软硬件设计，最后进行试验验证。研究内容如下： 1.从生产制造过程、使用过程、储存过程三个方面对锂动力电池组的不一致产生和恶化的原因进行机理分析，总结目前应用于改善电池组不一致性的解决方法；阐述均衡技术对于缓解电池在使用过程中不一致性的恶化，有效提高电池组使用寿命的重要意义。通过对锂动力电池进行相关试验，分析不同电池特性参数（电压、内阻、SOC）对于电池组不一致性问题的表现形式，选取开路电压作为搁置阶段的均衡变量，工作电压作为电池组充放电阶段的均衡变量。 2.对常见均衡电路拓扑结构的优缺点进行对比分析，选取基于反激式变压器的能量非耗散型均衡拓扑结构。并对反激式变压器的基本参数进行计算，搭建均衡仿真电路，选取电路控制参数。 3.选取电压极差作为均衡进入与退出的判断依据，，根据相关电池试验和电路要求，确定相应的控制阀值；针对电池组不同的工作阶段提出充电均衡、放电均衡和搁置均衡三种控制策略，利用均衡系统模型对均衡控制策略进行仿真验证。 4.以“主-从”分布式结构作为均衡系统的总体架构，完成电源模块、电压采集模块、电流采集模块、均衡模块以及通信模块的硬件电路设计，然后完成系统的软件设计。 5.完成系统调试，获得均衡电路在顶部均衡和底部均衡时的实际调试结果，与仿真结果进行了对比分析，然后通过搁置阶段和充放电阶段的台架试验验证均衡系统在电池组不同工作阶段对于改善电池组不一致性的控制效果。
[Abstract]:Because of the inconsistency between the cell units, when the lithium battery is used in the pure electric vehicle after series-parallel connection. The lower battery performance reached the charge / discharge cutoff voltage earlier, which led to the decrease of battery pack capacity utilization, reduced the driving range of pure electric vehicle, and increased the use cost of pure electric vehicle. It is not conducive to the use and promotion of pure electric vehicle. The equalization technology studied in this paper can manage the battery pack by monitoring the state information of battery pack in the process of using in real time. It can improve the influence of inconsistency in battery pack use, increase the capacity utilization ratio of battery pack, slow down the aging speed of battery, prolong the service life of battery pack, and increase the driving distance of electric vehicle. Based on the analysis of the mechanism of lithium power battery pack inconsistency, this paper designs the equalization system, designs the software and hardware of the system, and finally carries on the test verification. The research contents are as follows: 1. Analyze the causes of the inconsistency and deterioration of lithium power battery from three aspects: manufacturing process, use process and storage process. Summarize the current solutions to improve battery pack inconsistency; This paper expounds the importance of equalization technology in alleviating the deterioration of the inconsistency during the use of the battery and effectively increasing the service life of the battery pack. This paper analyzes the performance of different cell characteristic parameters (voltage, internal resistance) to the battery pack inconsistency, and selects the open circuit voltage as the equalization variable in the shelving stage. The working voltage is used as the equalization variable of battery charge and discharge stage. 2. The advantages and disadvantages of common equalization circuit topology are compared and analyzed. The energy non-dissipative equalization topology based on flyback transformer is selected, and the basic parameters of flyback transformer are calculated. Set up the equalization simulation circuit, select the control parameters of the circuit. 3. Selecting the voltage range as the basis for judging the equalization of entry and exit, according to the battery test and circuit requirements, determine the corresponding control threshold; Three control strategies, charging equalization, discharge equalization and shelving equalization, are proposed for different working stages of the battery pack. The equalization control strategy is verified by simulation using the equalization system model. 4. Taking the "master-slave" distributed structure as the overall structure of the equalization system, the hardware circuit design of the power supply module, voltage acquisition module, current acquisition module, equalization module and communication module is completed. Then the software design of the system is completed. 5. The system debugging is completed, and the actual debugging results of the equalization circuit in the top and bottom equalization are obtained, and the results are compared with the simulation results. Then the control effect of the equalization system in different working stages of the battery pack is verified by the bench tests in the shelving stage and the charging and discharging stage.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：TM912;U469.72

【参考文献】