电动汽车动力电池组可用容量评估方法研究

发布时间：2018-07-08 16:40

本文选题：锂离子动力电池 + 健康状态(SOH)　；参考：《合肥工业大学》2016年硕士论文

【摘要】：受环境污染和能源危机的影响,新能源汽车被列为国家重点扶持产业,未来新能源汽车的占有率会逐年递增,锂离子电池的性能优势使其成为纯电动车和混合动力汽车的动力电池首选。由于锂离子电池的固有特性导致电池SOC和SOH等状态参数很难直接被测量,所以电池模型和电池状态参数的研究一直是行业的热点。电池管理系统作为新能源汽车的重要组成部分是电池安全工作的保障,也是电池状态参数估算的设备平台,如何在电池管理系统中对电池状态参数准确估算目前仍是个技术难题。本文将在电池管理与测试系统平台的搭建基础上对动力电池可用容量和SOH的估算方法进行研究。首先研究锂离子电池的工作原理及电池结构特征,分析电池的电压特性、电池的温度特性、电池的内阻特性和电池的循环特性,并研究锂离子电池在使用过程中导致电池容量衰减的几种主要因素。其次分析几种常用等效电路模型的特征及优缺点,选择二阶RC等效电路模型模拟锂离子电池的工作特性,运用递推RLS算法对电池模型参数辨识估计,并验证电池模型实用性,为后期的可用容量估算获得了参数估算值。然后研究几种常用的电池可用容量估算方法,基于所选用的电池模型利用扩展卡尔曼滤波法对电池SOC进行估算,将获得的SOC值和库伦计数法所得到的SOC值进行比对,综合选取当前时刻的SOC值,最后利用SOC值和可用容量的关系得到电池可用容量和电池SOH值。最后搭建实验平台,验证电池模型的实用性,通过单体电池和成组电池的实验结果对所提出的方法进行验证,分析实验结果可看出所选的估算方法在精度方面具有很好的实验效果。
[Abstract]:Under the influence of environmental pollution and energy crisis, new energy vehicles are listed as the key industries supported by the state. In the future, the share of new energy vehicles will increase year by year. The performance advantage of lithium ion battery makes it the first choice of power battery for pure electric vehicle and hybrid vehicle. Due to the inherent characteristics of Li-ion battery, it is difficult to measure the state parameters such as SOC and SOH directly, so the research of battery model and battery state parameters has been a hot spot in the industry. As an important part of new energy vehicle, battery management system is the guarantee of battery safety and the equipment platform for estimating battery state parameters. How to accurately estimate battery state parameters in battery management system is still a technical problem. In this paper, based on the platform of battery management and test system, the available capacity of power battery and the estimation method of SOH are studied. Firstly, the principle and structure of Li-ion battery are studied. The voltage characteristic, temperature characteristic, internal resistance characteristic and cycle characteristic of battery are analyzed. Several main factors that lead to the battery capacity attenuation during the use of lithium ion battery are studied. Secondly, the characteristics, advantages and disadvantages of several commonly used equivalent circuit models are analyzed. The second order RC equivalent circuit model is selected to simulate the working characteristics of lithium ion battery. The recursive RLS algorithm is used to estimate the parameters of the battery model, and the practicability of the battery model is verified. The parameter estimation value is obtained for the later available capacity estimation. Then several commonly used methods for estimating the available capacity of the battery are studied. Based on the selected battery model, the SOC of the battery is estimated by using the extended Kalman filter, and the SOC value obtained by the Coulomb counting method is compared with that obtained by the Coulomb counting method. Finally, the relationship between SOC value and available capacity is used to obtain the available battery capacity and SOH value. Finally, an experimental platform is built to verify the practicability of the battery model, and the proposed method is verified by the experimental results of single cell and group battery. By analyzing the experimental results, we can see that the proposed estimation method has a good experimental effect in terms of accuracy.
【学位授予单位】：合肥工业大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U469.72

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