充放电控制策略对蓄电池效率和寿命的影响研究

发布时间：2019-05-15 16:51

【摘要】：随着经济的发展,人们对蓄电池的依赖程度越来越高。一方面电力系统要求的不间断供电,使蓄电池作为备用电源给设备供电,起到“削峰填谷”的作用；另一方面“十三五”规划中提出,实施新能源汽车推广计划,提高电动车产业化水平。电动汽车的发展离不开蓄电池,蓄电池的充放电效率和寿命是制约电池储能技术和电动汽车发展的关键因素之一,但国内外研究主要集中于蓄电池的建模、电压电流的测试以及修复,对电池的充放电效率和寿命的研究较少。本文以铅酸蓄电池的充放电效率和寿命为研究对象,设计了一套充放电效率测试系统。在此平台上,测试铅酸蓄电池在不同充放电策略下的充放电效率和寿命,通过分析测试数据,得出提高充放电效率和寿命的控制策略。本文主要工作可以总结为以下四个方面：(1)铅酸蓄电池电化学原理和基本参数的分析根据铅酸蓄电池的内部结构,着重分析了其在充电和放电过程中的电化学原理,研究了不同充放电的控制方式及其对蓄电池充放电效率和寿命等参数的影响,最后详细介绍了蓄电池充放电效率和寿命的测试方法。(2)充放电效率测试系统的设计该系统以型号为TMS320F28335的DSP芯片为控制核心,主要由硬件电路设计和软件程序编写两部分组成。其中,硬件设计主要分为充放电单元、检测单元、驱动单元以及辅助电源的设计；软件部分包括主程序设计、充放电控制程序设计以及通讯程序设计。它能够对充放电电压电流的设置,显示蓄电池端电压、电流、容量以及电量,并通过RS485通讯将数据上传至上位机,方便数据的管理和分析,实现了蓄电池充放电效率的测试。最后通过对牵引用(电动车专用)12V36Ah铅酸蓄电池进行测试实验,验证了该系统的可行性。(3)充放电控制策略对蓄电池效率影响的分析以牵引用(电动车专用)12V120Ah铅酸蓄电池为测试对象,通过充放电电流为5.2A、12A、20A和40A的测试实验,得到不同充放电电流下的充放电效率,通过分析测试数据发现,20A充放电时电池的充放电效率达到最大为86%。在MATLAB中对20A充放电策略下的电压及电流数据进行拟合,得到拟合函数。通过控制充放电电压和电流按照该拟合函数变化,就可以实现充放电效率最大化。(4)充放电控制策略对蓄电池寿命的影响分析对电池进行循环寿命测试实验,根据实验数据分析不同充放电电压和放电深度对电池寿命的影响。着重分析了20A放电电流下蓄电池寿命,对蓄电池进行300次的寿命测试实验,每10次进行一次容量测试,得到蓄电池容量保持率的变化曲线。发现电池在20次循环时开始进入稳定期,250次循环后容量开始急剧衰减,得到蓄电池寿命的衰退速率是先增大后减小再增大的结论。并根据上述分析结果设计了电动教练车的蓄电池寿命测试方案。
[Abstract]:With the development of economy, people rely more and more on batteries. On the one hand, the uninterrupted power supply required by the power system makes the battery supply power to the equipment as a standby power supply, which plays the role of "peak cutting and valley filling"; On the other hand, the 13th five-year Plan puts forward that the promotion plan of new energy vehicles should be implemented to improve the industrialization level of electric vehicles. The development of electric vehicle can not be separated from battery. The charging and discharging efficiency and life of battery are one of the key factors that restrict the development of battery energy storage technology and electric vehicle, but the research at home and abroad mainly focuses on the modeling of battery. The charge and discharge efficiency and life of the battery are less studied in the test and repair of voltage and current. In this paper, a charge-discharge efficiency test system for lead-acid battery is designed, which takes the charge-discharge efficiency and life of lead-acid battery as the research object. On this platform, the charge-discharge efficiency and life of lead-acid battery under different charge-discharge strategies are tested, and the control strategy to improve the charge-discharge efficiency and life is obtained by analyzing the test data. The main work of this paper can be summarized as follows: (1) the electrochemical principle and basic parameters of lead-acid battery are analyzed according to the internal structure of lead-acid battery. The effects of different charge and discharge control methods on the charge and discharge efficiency and life of the battery were studied. Finally, the test method of battery charge and discharge efficiency and life is introduced in detail. (2) the design of charge and discharge efficiency test system is based on DSP chip of model TMS320F28335. It is mainly composed of hardware circuit design and software programming. Among them, the hardware design is mainly divided into charge and discharge unit, detection unit, driving unit and auxiliary power supply design; the software part includes the main program design, charge and discharge control program design and communication program design. It can set the charge and discharge voltage and current, display the battery terminal voltage, current, capacity and electric quantity, and upload the data to the upper computer through RS485 communication, which is convenient for the management and analysis of the data, and realizes the test of battery charge and discharge efficiency. Finally, through the test experiment of 12V36Ah lead-acid battery, The feasibility of the system is verified. (3) the influence of charge-discharge control strategy on battery efficiency is analyzed. 12V120Ah lead-acid battery for traction (electric vehicle) is taken as the test object, and the charge-discharge current is 5.2 A, 12A. The charge-discharge efficiency of 20A and 40A is obtained under different charge-discharge currents. Through the analysis of the test data, it is found that the maximum charge-discharge efficiency of 20A battery is 86%. The voltage and current data of 20A charge-discharge strategy are fitted in MATLAB, and the fitting function is obtained. By controlling the change of charge and discharge voltage and current according to the fitting function, the charge and discharge efficiency can be maximized. (4) the influence of charge and discharge control strategy on battery life is analyzed and the cycle life test of battery is carried out. The effects of different charge-discharge voltage and discharge depth on battery life were analyzed according to the experimental data. The battery life under 20A discharge current is analyzed emphatically. the battery life test is carried out 300 times, and the capacity test is carried out every 10 times, and the change curve of battery capacity retention rate is obtained. It is found that the battery begins to enter the stable stage at 20 cycles, and the capacity begins to decline sharply after 250 cycles. It is concluded that the decay rate of battery life increases at first and then decreases and then increases. According to the above analysis results, the battery life test scheme of electric coach is designed.
【学位授予单位】：陕西科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TM912;U469.72

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