电动汽车用的一种胶体动力电池特性研究

为了研究一种新型胶体动力电池的充放电特性,评价其在电动汽车上的使用性能,在不同的工况下对该电池组进行了充放电试验,基于试验数据绘制了该电池不同使用工况下的充放电曲线,研究了其充放电性能,并分析了充放电倍率、充放电温度以及充电电压对电池充放电性能及其一致性的影响,提出了该电池在电动汽车上合理使用的建议。     

动力电池循环寿命预测方法研究

以某锰酸锂锂离子动力电池为例,研究了利用性能退化数据进行动力电池寿命预测的方法.研究发现该电池容量基本符合幂函数的衰退轨迹,利用该衰退模型外推了电池伪失效寿命;对伪失效寿命的分布进行了研究,结果威布尔分布的拟合效果最好,基于威布尔寿命分布对该电池的可靠性进行了评估.分析了用于寿命预测的实际循环数据的多少对预测精度的影响.该寿命模型和可靠性评定方法具有较高的精度,解决了动力电池寿命评估周期长和成本高的问题.     

电动汽车电池组连接可靠性及不一致性研究

通过对电动汽车用锂离子电池特性的研究,建立了电池组模型并分析了充放电基本规律,重点讨论了电池组可靠性和电池组中单个电池性能不一致性对电池组性能和寿命的影响及对电动汽车行驶性能的影响,提出了在使用方面的解决方案.     

[电动汽车稳定性控制]履带车辆混合驱动系统自动化建模

Tracked vehicle hybrid drive system is a kind of electromechanical transmission system and equipment. In order to improve the efficiency of system design and modeling, an automated modeling method was proposed for a series-parallel tracked vehicle hybrid drive systems. Based on the modeling of a power combining device and a power convergent device, the automated modeling principles were illustrated and the automated modeling rules and the screening conditions were further proposed. Then the final model equation eliminated intermediate quantity was derived. With the automated modeling method, some tracked vehicle hybrid drive systems were modeled in Simulink to validate the method. The automated modeling processes were programmed. And as an application demonstration for the automated modeling, optimal configuration seeking was described. The results show the method may build the model and screening the configuration automatically, which is a powerful method for rapid and automated modeling of tracked vehicle hybrid drive systems.     

电动汽车感应电机驱动系统矢量控制的双CPU实现

为电动汽车感应电动机驱动系统设计开发一套矢量控制系统,其硬件系统是通过双CPU-单片机80C196KC和数字信号处理器(DSP)TMS320F240来实现的.通过坐标变换得到了适用于矢量控制的同步旋转坐标系(m-t轴)下的感应电动机基本数学方程,推出了转子磁链方程和转矩方程.系统软件基于这些数学模型来实现感应电动机转子磁场定向矢量控制,并给出了软件程序流程及MATAB/SIMULAINK下的部分仿真结果和试验结果.仿真与试验结果表明,基于双CPU的感应电机矢量控制系统具有良好的动态特性,较宽的调速范围和恒转矩区域,电机及其控制系统效率高等优点,转子磁场定向矢量控制策略是可行的.     

用CAD技术进行汽车底盘总布置设计方法的研究

在数据库和图形库的基础上,运用ObjectARX工具对AutoCAD2000进行二次开发,论述了总布置设计过程、原理和方法,建立了总布置设计Petri网数学模型,完成了汽车底盘总布置设计,在一定程度上体现了虚拟设计思想.     

电动汽车电池安全事故分析与研究现状

电池安全问题严重影响了电动汽车的普及与推广,近年来电动汽车电池起火事件频发,引起了极高的社会关注度。本文对近五年的主要电动汽车安全事故进行统计分析,归纳电动汽车起火事件的历年起因分布及规律,对几种主要的事故起因背后的电池故障特性及其对热失控触发机理进行了描述,进而综述了国内外主要团队在电池过充电、外部短路、内部短路、过放电以及挤压碰撞等电池安全问题的研究现状,讨论现有主要研究成果及不足之处,最后对电池安全及热失控的诊断、预警的研究趋势及思路进行几点探讨。     

基于MATLAB SIMULINK的电传动履带车辆转向性能仿真

首先采用一种简单可行的电传动方案建立了新的电传动履带车辆模型。然后在对电传动履带车辆转向行驶基本理论分析的基础上,结合鼠笼式异步电机模型及其经典矢量控制方法,分别采用独立式和差速式两种控制方案对电传动履带车辆的转向行驶性能进行了仿真分析。结果表明：采用速度控制可以很好地实现车辆转向;为使扭矩和电流平稳,参考速度应以平缓的方式给定;对不同的转向工况,应采取不同的转向模式;再生转向时产生的再生能量很大,应对其加以充分重视和利用。     

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.     

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.