SOC distribution-based modeling for lithium-ion battery for electric vehicles using numerical optimization

In order to simulate electrical characteristics of a lithium-ion battery used in electric vehicles in a good manner,a three-layer battery model is established.The charge of the lithium-ion battery is assumed to distribute among the three layers and their interaction is used to depict hysteresis and relaxation effect observed in the lithium-ion battery.The model parameters are calibrated and optimized through a numerically nonlinear least squares algorithm in Simulink Parameter Estimation Toolbox for an experimental data set sampled in a hybrid pulse test of the battery.Evaluation results showed that the established model is able to provide an acceptable accuracy in estimating the State of Charge of the lithium-ion battery in an open-loop fashion for a sufficiently long time and to describe the battery voltage behavior more accurately than a commonly used battery model.The battery modeling accuracy can thereby satisfy the requirement for practical electric vehicle applications.     

电动汽车电池管理系统和剩余容量计研究

目的研究和开发电动汽车电池管理系统,实现铅酸储能蓄电池的剩余容量计量技术。方法通过对电动汽车铅酸储能电池基本电化学特性分析,采用了以安时法－Ｐｅｕｋｅｒｔ公式－开路电压法为基本算法,进行电池管理系统的开发,同时考虑了温度、自放电、使用循环寿命等因素对铅酸电池剩余容量预测的影响。结果所开发的管理系统铅酸电池剩余容量静态充放电实验计量误差小于５％,提供给驾驶员一个较准确的剩余容量,并对电池组中每声池进行监测,对铅酸电池的过放电和过充电等非正常工作情况及时报警,实用性强。结论电动汽车电池管理系统可以有效延长电池的使用寿命,优化电池能量的利用,提高电动汽车的性能。     

Fuzzy Model for Estimation of the State-of-Charge of Lithium-Ion Batteries for Electric Vehicles

A fuzzy model was established to estimate the state of charge (SOC) of a lithium-ion battery for electric vehicles. The robust Gustafson-Kessel (GK) clustering algorithm based on clustering validity indices was applied to identify the structure and antecedent parameters of the model. The least squares algorithm was utilized to determine the consequent parameters. Validation results show that this model can provide accurate SOC estimation for the lithium-ion battery and satisfy the requirement for practical electric vehicle applications.     

过盈配合时齿轮内径与预应力关系研究

齿轮过盈配合在工程中一直被广泛使用。由过盈配合产生的预应力对齿轮的强度和寿命影响很大。本文针对某发动机过盈装配的曲轴齿轮进行了基于刚度模型和有限元法的分析，得出齿轮内径、过盈量与预应力的关系，为采用过盈配合齿轮的设计提供借鉴。     

New P3D Hydraulic Fracturing Model Based on the Radial Flow

Pseudo three-dimension (P3D) hydraulic fracturing models often overpredict the fracture height for a poorly contained fracture. To solve this problem, a new method is presented in shaping the P3D fracture geometry on the basis of the fundamental theory and the original 1D fluid flow is replaced with a more representatively radial flow. The distribution of the fluid in the modified fluid field is analyzed and a sound explanation to the problem is given. Due to the consideration of the fluid flow in the vertical direction, the modified model can predict the fracture height much better. To validate the rationality of the radial fluid flow assumption, the distribution of the fluid in the modified fluid field is simulated with the plane potential flow by using finite element method. And the results agree effectively with those from the assumption. Through comparing with the full 3D model, the results show that this new P3D model can be used to aid the fracturing design and predict the fracture height under poorly contained situation.     

电动公交大客车驱动系统控制特性分析

针对一种具有永磁加增磁绕组复合励磁方式的新型直流牵引电动机,研制了电动公交大客车的驱动控制系统。建立了永磁加增磁复合励磁电动机驱动控制系统的数学模型。应用线性二次型性能指标最优控制方法设计了电动公交大客车加速度控制系统的控制参数,并且进行了计算。实验结果表明,该驱动控制系统的抗干扰能力强、调节特性快速、平稳,能很好地满足电动公交大客车的动力特性要求。     

电动汽车电池组连接方式研究

为了了解电动汽车电池组连接方式对电池组使用性能的影响,通过大量的电动汽车运行试验,对电动汽车电池组的连接方式进行了研究。建立了电池组连接模型,并重点分析讨论了不同连接模型对电池组连接可靠性和电池不一致性的影响,提出了合理的连接方式选择原则。     

动力电池充放电效率测试分析

从理论上对动力电池充放电效率的不同测试方法进行了分析,建立了电池充放电效率的测试模型,提出了直流脉冲法快速测试电池在不同放电率和放电深度下的充放电效率。同时采用不同的测试方法测试了不同动力电池的充放电效率,分析了不同放电率和不同放电深度对电池效率的影响。直流脉冲法和其它测试方法相比,测试结果基本相同,但这种测试方法可以缩短测试的时间。     

大数据分析技术在新能源汽车行业的应用综述——基于新能源汽车运行大数据

为应对化石能源危机和环境污染问题,新能源汽车技术的发展与应用引起广泛重视。新能源汽车具有高信息化的特点和智能网联化的发展趋势,在日常运行中会产生大量行驶数据信息。利用海量多源异构数据进行安全预警与监管、车辆技术分析,是推动我国新能源汽车行业发展的关键。综述了大数据分析技术在新能源汽车行业的应用情况,概述了大数据分析技术的基础理论、发展历程,介绍了新能源汽车国家监测与管理平台的架构和功能,并着重阐述了新能源汽车大数据分析过程。分别从动力电池数据、汽车运行数据和充电数据的角度出发,分析了现有的研究方向和研究方法,列举了部分研究成果和应用情况。最后,对当前新能源汽车大数据分析领域存在的问题和发展应用前景进行了总结和展望。     

基于驱动信号的加速车身速度算法

为了改进目前在汽车动力学控制系统研究中常用的由车辆的非驱动轮速获得车身速度的计算方法的局限性和精确性,通过建立行驶车辆及车轮部分的动力学及运动学模型,推导并提出了基于驱动轮速信号带可调整加权因子的车身速度算法. 编制了嵌有车速算法的Matlab程序并对不同路面上加速的车辆工况进行了仿真. 仿真结果与试验结果吻合良好,验证了算法的可信性.