【作者】 汤桃峰；

【导师】 杨阳；

【作者基本信息】 重庆大学 ， 车辆工程， 2011， 硕士

【摘要】 日益枯竭的石油资源和环境污染的压力使得传统的燃油汽车发展面临严重的挑战。如今汽油的零售价进入“八元”时代,节能和环保成为汽车发展的新目标。为此电动汽车得到了迅速发展,但是动力电源的性能和成本已成为影响整车推广的关键因素。动力电源是新能源车的主要储能元件,对电动车的续驶里程、加速性能和最大爬坡度等性能产生直接的影响,而且动力电池的成本更是占到了整车售价的一半,因此对动力电池的研究是非常必要的。由于锂离子动力电池具有比能量和比功率高等优点,被越来越多的汽车厂家作为新能源汽车的动力电池。①本文首先介绍了新能源汽车和动力电源的发展趋势,分析了动力电池组应用存在的问题;介绍了动力电池有关的电化学基本概念②设计了动力电池的实验内容与实验流程,并在整车实际工况下,对电池相关性能进行实验,得到了锂电池的充放电、开路电压、内阻及放电效率特性,这为电池的选择,电池模型的建立和电池的荷电状态(State of Charge,SOC)预估打下基础。③基于PNGV等效电路模型,通过实验计算得到了电池模型参数以及建立了电池端电压的仿真模型并进行了验证,提出了一种以电池等效模型的开路电压插值估算电池荷电状态(SOC)的方法。④建立了电池放电过程中荷电状态(SOC)仿真模型,并确定了常温下的模型仿真参数,进行了两种放电工况进行实验:a、恒流放电工况;b、变电流放电工况,结合电池实验结果和仿真结果进行了对比分析。结合开路电压插值估算SOC的方法能保持良好的精度,SOC值不会波动,简单易于实现,满足电动汽车SOC估计要求。⑤通过锂离子电池充放电特性、电量估算和单体电压检测,为评估电池组的差异性提供了良好的基础。基于实验分析了电池组充放电循环寿命衰减以及电池组不一致性的产生原因,然后通过单体电池电压检测电路逐一检查单体电池的工作状态,分析了影响电池组一致性的因素。更多还原

【Abstract】 Traditional engine vehicle development confronts with severe challenges, because of the increasingly serious energy and environmental pressure. When the retail price of gas get into“8 yuan”era , Energy-saving and environmental protection will must become new goal of vehicles development. Therefore, EV(electric vehicle) have got rapid development, but Power battery’s performance and costs has become a key factor in the promotion of EV。Power electrical source is the main energy storage element of electric vehicle. So the performance of batteries influences directly on vehicle’s performance. And the batteries of costs is accounted for half the price of EV, therefore, research on the battery is necessary.①Firstly, the trends of development of electric vehicle, application of the Power battery problems,the basic characteristics of battery is introduced in this paper. Then, test content and test process of the batteries are carried out.②Based on the performance experiment of batteries, the evaluation method of State of Charge(SOC) in lithium-ion batteries is researched. And a new evaluation method of SOC is investigated.③With the model of PNGV battery, the method of SOC based on open-circuit voltage was brought forward considering the temperature effect on the parameters of the equivalent battery model .④By lithium-ion battery charge and discharge characteristics, and power estimation, assessment of the battery pack can be a good difference. Based on the test of the battery charge and discharge cycle life and battery decay causes inconsistency, and then single battery voltage detection circuit to know the working status of single cells, and then analyzes consistency of the battery pack⑤A simulation model were set up based on Matlab/Simulink and obtained the parameters of the model by the lithium batteries charge-discharge test and HPPC test . Simulation and test result show that the PNGV model is very precise and can simulate the battery characterizations of charge and discharge as well. The cumulative error and inaccurate estimation of the initial value by the ampere-hour(AH) approach can be effectively avoided by the estimate method of SOC based on open-circuit voltage.And the estimation value of SOC can be kept highly precise, and the SOC error is less than 5%. The results show that the estimate method meets requirements.更多还原