汽车电控液压助力转向系统设计

汽车电控液压助力转向系统设计

收藏

压缩包内文档预览:

资源预览需要最新版本的Flash Player支持。
您尚未安装或版本过低,建议您

汽车电控液压助力转向系统设计,汽车,液压,助力,转向,系统,设计
编号:22889753    类型:共享资源    大小:605.18KB    格式:ZIP    上传时间:2019-11-03 上传人:机****料 IP属地:河南
30
积分
关 键 词:
汽车 液压 助力 转向 系统 设计
资源描述:
汽车电控液压助力转向系统设计,汽车,液压,助力,转向,系统,设计
内容简介:
毕 业 设 计(论 文)任 务 书 设计(论文)题目:汽车电控液压助力转向系统设计 学生姓名:任务书填写要求1毕业设计(论文)任务书由指导教师根据各课题的具体情况填写,经学生所在专业的负责人审查、系(院)领导签字后生效。此任务书应在毕业设计(论文)开始前一周内填好并发给学生。2任务书内容必须用黑墨水笔工整书写,不得涂改或潦草书写;或者按教务处统一设计的电子文档标准格式(可从教务处网页上下载)打印,要求正文小4号宋体,1.5倍行距,禁止打印在其它纸上剪贴。3任务书内填写的内容,必须和学生毕业设计(论文)完成的情况相一致,若有变更,应当经过所在专业及系(院)主管领导审批后方可重新填写。4任务书内有关“学院”、“专业”等名称的填写,应写中文全称,不能写数字代码。学生的“学号”要写全号,不能只写最后2位或1位数字。 5任务书内“主要参考文献”的填写,应按照金陵科技学院本科毕业设计(论文)撰写规范的要求书写。 6有关年月日等日期的填写,应当按照国标GB/T 740894数据元和交换格式、信息交换、日期和时间表示法规定的要求,一律用阿拉伯数字书写。如“2002年4月2日”或“2002-04-02”。毕 业 设 计(论 文)任 务 书1本毕业设计(论文)课题应达到的目的: 汽车转向系统是影响汽车操纵稳定性、行驶安全性和驾驶舒适性的关键部件。在追求高效节能、高舒适性和高安全性的今天,电控液压助力转向系统(EHPS)作为一种新的汽车动力转向系统,以其良好的操作特性和准确性,成为动力转向技术研究的主流方向。 本论文以某轿车电控液压助力转向系统(EHPS)为研究目标,通过电控液压助力转向系统结构、工作原理对系统进行了静、动态计算及分析,在此基础上对系统进行了优化设计。 2本毕业设计(论文)课题任务的内容和要求(包括原始数据、技术要求、工作要求等): 1. 在阅读大量与课题相关文献资料的基础上,综合评述国内外对汽车电控液压助力转向系统(EHPS)的研究现状,为进一步研究奠定基础;2.能够熟练掌握电控液压助力转向系统结构、工作原理;3.通过本毕业设计课题论文的撰写,学生能初步掌握课题研究的方法和步骤,能独立完成课题项目的调查、研究、总结、判断,从而具备一定的项目研究能力,并最终完成一篇符合金陵科技学院毕业论文规范的系统技术文档。毕 业 设 计(论 文)任 务 书3对本毕业设计(论文)课题成果的要求包括图表、实物等硬件要求:1. 在阅读大量与课题相关文献资料的基础上,综合评述国内外对汽车电控液压助力转向系统(EHPS)的研究现状;2.能够熟练掌握电控液压助力转向系统结构、工作原理;3.完成一篇符合金陵科技学院毕业论文规范的系统技术文档;4. 能够完成各项任务,参加最后的毕业设计答辩。4主要参考文献: 1 汽车电控液压转向系统建模与仿真 赵金海 2007 2秦淑英 中心区操纵稳定性参数灵敏度分析与方向盘力矩特性研究 吉林大学硕士论文,2004 3 王春行,吕志咏. 液压控制系统M. 北京:机械工业出版社,1995. 4 罗抟翼, 程桂芬, 付家才,等. 控制工程与信号处理M. 北京:化学工业出版学,2004. 5 李永堂,雷步芳,高雨茁. 液压系统建模与仿真M. 北京:冶金工业出版社,2003. 6 张利平. 液压控制系统及设计M. 北京:化学工业出版社,2006. 7 王守城,段俊勇. 液压元件及选用M. 北京:化学工业出版社,2007. 8 王忠礼,段慧达,高玉峰. MATLAT 应用技术M. 北京:清华大学出版社,2007. 10 黄勇. 电液伺服加载系统的研究与设计D. 西安:西北工业大学,2001 11 胡良谋,李景超,曹克强. 基于 MATLAB/SIMULINK 的电液伺服控制系统的建模与仿真研究J. 机床与液压,2003,(03):230-246. 12 林涛,吴洪涛,赵强. 基于 MATLAB/SIMULINK的电液模拟仿真分析J. 机床与液压,2007,35(03):167-169,82. 14 高翔,孔丽英,孙贵芳. 电液伺服系统的仿真与自校正 PID控制器的设计J. 海军工程大学学报,2001,13(05):33-37. 15 熊汉文. 单片机实现的智能 PID控制器在液压系统中的应用研究D. 哈尔滨:哈尔滨工业大学,2001. 毕 业 设 计(论 文)任 务 书5本毕业设计(论文)课题工作进度计划:一、2015.12.05至2015.12.16:确定选题,填写审题表;指导教师下发任务书,学生查阅课题相关参考文献、资料,撰写开题报告;二、2015.12.17至2016.01.26:提交开题报告、外文参考资料及译文、毕业设计(论文)大纲;开始毕业设计(论文);三、2016.01.27至2016.04.15:具体设计或研究方案实施,提交毕业设计(论文)草稿,填写中期检查表;四、2016.04.16至2016.05.04:完成论文或设计说明书、图纸等材料,提交毕业设计(论文)定稿,指导老师审核;五、2016.05.05至2016.05.09:提交毕业设计纸质文档,学生准备答辩;评阅教师评阅学生毕业设计(论文);六、2016.05.10至2016.05.16:根据学院统一安排,进行毕业设计(论文)答辩。所在专业审查意见: 通过 负责人: 2016 年 1 月 10 日毕 业 设 计(论 文)开 题 报 告 设计(论文)题目:汽车电控液压助力转向系统设计 学生姓名:开题报告填写要求 1开题报告(含“文献综述”)作为毕业设计(论文)答辩委员会对学生答辩资格审查的依据材料之一。此报告应在指导教师指导下,由学生在毕业设计(论文)工作前期内完成,经指导教师签署意见及所在专业审查后生效;2开题报告内容必须用黑墨水笔工整书写或按教务处统一设计的电子文档标准格式打印,禁止打印在其它纸上后剪贴,完成后应及时交给指导教师签署意见;3“文献综述”应按论文的框架成文,并直接书写(或打印)在本开题报告第一栏目内,学生写文献综述的参考文献应不少于15篇(不包括辞典、手册);4有关年月日等日期的填写,应当按照国标GB/T 740894数据元和交换格式、信息交换、日期和时间表示法规定的要求,一律用阿拉伯数字书写。如“2004年4月26日”或“2004-04-26”。5、开题报告(文献综述)字体请按宋体、小四号书写,行间距1.5倍。 毕 业 设 计(论文) 开 题 报 告 1结合毕业设计(论文)课题情况,根据所查阅的文献资料,每人撰写不少于1000字左右的文献综述: 汽车电控液压助力转向系统设计1.课题研究意义 转向系统是影响汽车操纵稳定性、舒适性和行驶安全性的关键系统之一,在转向系统的设计中,存在着转向轻便性和转向灵敏性之间的矛盾。汽车在转向的时候,由于地面的阻力矩的作用,在没有助力的情况下用手臂转动转向盘会感觉到比较沉重,所以,需要采取助力转向来解决转向轻便性问题。而随着车速的增加,车轮与地面的阻力矩减小,在提供相同助力的情况下,高速时会令人感觉到转向盘发飘,转向盘角速度过大时,助力容易出现滞后现象,因此需要采用实时调节助力大小来解决转向灵敏性问题。 随着汽车电子事业有了很大的提高,为了解决上述问题提供了条件,同时为了让汽车转向助力更轻便、更节能、更安全,就需要对各电子转向产品进行研究,而本课题正是沿着这个方向对汽车的转向系统进行了研究。由于传统液压助力转向系统目前还占主导地位,而且其存在一定上的缺陷,所以对其进行改造和更新变得更有实际意思。目前考虑经济成本和运行效果:与 EPS 系统相比,EHPS 系统采用液压提高助力,使助力比较平滑,手感很好;对于以前的HPS 系统,可以经过相对简单的改装即可成为 EHPS 系统:EHPS 系统也继承了HPS 系统的优点,能提供很足的助力,所以电控液压助力转向系统是最佳选择,它能提供比其更安全、更舒适的转向操控性和节能效果。在可预见的将来,电控液压助力转向系统将会有一定的生存空间1。2.工作原理 电控液压动力转向系统主要通过车速传感器和位移传感器将车速和反向盘转角传递给电子元件或微型计算机系统,控制电液转换装置改变动力转向的助力特性 ,使驾驶员的转向手力根据车速和行驶条件变化而改变 ,即在低速行驶或急转弯时能以很小的转向手力进行操作 ,在高速行驶时能以稍重的转向手力进行稳定操作,使操纵性和稳定性达到最合适的平衡状态。电控液压动力转向系统的种类很多 ,但其基本原理都是通过在油泵或转向器上加装电子执行机构或辅助装置,根据车速、方向盘转角控制液压系统的流量或压力。控制器根据车速信号、转向盘转角信号控制油泵的流量,达到助力转向的目的。EHPS 系统一般由电气装置和机械装置两部分组成,如图 1-1 所示。电气部分由车速传感器、转角传感器和电子控制单元 ECU 组成;机械装置包括齿轮齿条转向器、控制阀及管路。 图1-13. 转向轻便型和转向路感 汽车在转向时,驾驶员需要克服转向阻力矩。一般驾驶员都希望车辆转向力“轻”些好,转向轻可以减少驾驶员的体力消耗。但太“轻”又不好,因为转向力中还包含着前轮侧向力的信息,使汽车的运动状态(包括车轮与路面的附着状态)与驾驶员手上的力有一种对应关系,这就是“路感”。如果这种“路感”很清晰,驾驶员就会感到“心中有数”,所以如果转向盘上转向力太小了,“路感”也就没有了,从这个意义上说,转向力又不能太小。但同样也不应太大,如果过大就会使得驾驶员感觉疲劳。因此良好的转向盘力矩特性可减轻驾驶员的疲劳,同时起到很好的控制汽车与反馈信息的作用。所以汽车转向中的轻与灵就成为一对矛盾体,在设计时必须保证驾驶员操纵的轻便性,还要使驾驶员获得良好的路感。 1999 年,通用公司采用瑞典驾驶模拟器(VTI)运用多名驾驶员,测试了在侧向加速度为0.3g 时,随车速的不同,驾驶员所偏爱的方向盘力矩的试验。 国内一些研究机构给出了我国驾驶员平均所偏爱的方向盘力矩随侧向加速度和车速变化曲线,随车速的增加,我国驾驶员平均所偏爱的转向力矩逐渐增大,在各侧向加速度下的变化趋势基本相同 2。在侧向加速度为 1.2m/s2 时驾驶员所偏爱的方向盘力矩较小,大于 2.5m/s2 的各侧向加速度下的方向盘力矩明显增大,但在 2.5m/s2、4.5 m/s2下相差不大。如表 1-2所示驾驶员所偏爱的方向盘力矩随侧向加速度的增大而逐渐增大,车速在 40 km/h 时,转向盘力矩最小,当车速在 120 km/h 时,转向盘力矩最大。在侧向加速度大于 2.5m/s2后,转向盘力矩变化平缓。表1-2由以上可知随着车速和侧向加速度的变化,驾驶员期望的转向盘力矩是不同的,这是作为设计电控液压助力系统的重要依据。 表1-24. 电液伺服系统类型及特点 根据输入信号的形式不同,电液伺服系统可以分为模拟伺服系统和数字伺服系统两类。在模拟伺服系统中,输入信号、反馈信号、偏差信号、及其放大、校正都是连续的模拟量。电信号是直流量或交流量。模拟伺服系统重复精度高,但分辨能力较低。伺服系统的精度在很大程度上取决于检测装置的精度,而模拟式检测装置的精度一般低于数字式检测装置,所以模拟伺服系统分辨率低于数字伺服系统。另外模拟伺服系统中微小信号容易受到噪声和零漂的影响,因此当输入信号接近或小于输入端的噪声和零漂时,就不能进行有效的控制了。在数字伺服系统中,全部信号或部分信号是离散参量。数字检测装置有很高的分辨能力,所以数字伺服系统可以得到很高的绝对精度。它还利用计算机对信息进行贮存、解算和控制,在大系统中实现多环路、多参量的实时控制,因此有广阔的发展前景。液压传动与其它的传动方式相比,液压传动有下列优点: 1,在液压传动运行中,能方便地进行速度调节。 2,在同等功率的情况下,液压传动装置的体积小、重量轻、惯性小、结构紧 凑,而且能传递大的力和转矩。 3,液压传动工作平稳,反应快,冲击小,能高速启动。 4,液压传动装置的控制、调节比较简单,操纵比较方便、省力,易于实现自动化。与电气控制配合使用能实现复杂的顺序动作和远程控制。 5,液压传动装置易于实现过载保护,系统超负载时,油液会经溢流阀回油箱。由于采用油液作为工作介质,液压元件能自行润滑,因而使用寿命长。 6,液压传动元件和装置易于实现系列化、标准化、通用化、易于设计、制造和推广使用。 7,液压传动易于实现回转、直线运动,且元件排列布置灵活。 8,液压传动中,由于功率损失所产生的热量可由流动着的油液带走,因此可避免在系统某些局部位置产生过度温升。5. 液压传动系统的组成 液压伺服控制系统由以下一些基本元件组成: 1,输入元件,它给出输入信号加于系统的输入端。该元件可以是机械的、电气的等。 2,执行机构指各种类型的液压缸、液压马达。其作用是将油液的压力能转变成机械能,使工作机能驱动负载,实现规定的运动。 3,反馈测量元件,测量系统的输出并转换为反馈信号。各种传感器常作为反馈测量元件。 4,比较元件,将反馈信号与输入信号进行比较,给出偏差信号。 5,放大转换元件,将偏差信号放大、转换成液压信号(流量或压力)。如伺服放大器、机液伺服阀、电液伺服阀等。 6,控制对象,被控制的机器设备或物体,即负载。 电液伺服阀既是电液转换元件,又是功率放大元件。它能够将输入的微小电气信号转换为大功率的液压信号(流量与压力)输出。根据输出的油压信号不同,电液伺服阀可分为电液流量控制阀和电液压力控制阀两大类。 在电液伺服系统中,电液伺服阀将系统的电气部分与油压部分连接起来,实现电液信号的转换与放大以及对液压执行元件的控制。电液伺服阀是电液伺服系统的关键部分,它的性能及正确使用,直接关系到整个系统的控制精度和响应速度,也直接影响到系统工作的可靠性和寿命。电液伺服阀控制精度高、响应速度快,是一种高性能的电液控制元件,在液压伺服系统中得到广泛的应用。 电液伺服阀通常由力矩马达、液压放大器、反馈机构三部分组成。力矩马达或力马达的作用是把输入的电气控制信号转换为力矩或力,控制液压放大器运动。而液压放大器的运动又去控制液压能源流向液压执行机构的流量或压力。力矩马达或力马达的输出力矩或力很小,在阀的流量比较大时,无法直接驱动功率级阀的运动,此时需要增加液压前置级,将力矩马达或力马达的输出加以放大,在去控制功率级阀,这就构成二级或三级电液伺服阀。如图 1-3所示,为力反馈两级电液伺服阀简图。图1-3 力反馈两级电液伺服阀伺服阀输出级所采用的反馈机构或平衡机构是为了是伺服阀的输出流量或输出压力获得与输入电气控制信号成比例的特性。由于反馈机构的存在,使伺服阀本身成为一个闭环控制系统,提高了伺服阀的控制性能。 图 1-3 力反馈两级电液伺服阀毕 业 设 计(论文) 开 题 报 告 2本课题要研究或解决的问题和拟采用的研究手段(途径): 课题研究内容1、进行文献查询了解电液伺服系统类型及特点 ,了解液压传动系统的组成; 2、进行系统元件的数据模型的建立; 3、进行液压系统的设计; 4、进行电液伺服系统的仿真 ;5、学习有关软件知识,并能熟练使用软件进行转向系统的设计。 课题研究手段1、通过相关的手册及文献资料进行分析设计2、建立对转向系统元件的数据模型3、通过仿真软件搭建电液伺服系统模型进行仿真分析。 毕 业 设 计(论文) 开 题 报 告 指导教师意见:1对“文献综述”的评语: 综述内容较为丰富,参考文献合理,概括了课题所包含的研究内容的相关背景、基础知识、发展现状等,同时还对本课题所研究的任务进行了一定的阐述,对本课题的研究有一定的指导意义。 2对本课题的深度、广度及工作量的意见和对设计(论文)结果的预测: 本课题难度中等,工作量适中,研究涉及相关知识范围较广,对系统设计及程序设计能力亦有较高的要求。通过查阅相关资料,同学交流,指导老师的指导,并结合大学知识的积累,该同学可以在规定时间内完成符合本科生要求的毕业设计。 3.是否同意开题: 同意 不同意 指导教师: 2016 年 03 月 06 日所在专业审查意见:同意 负责人: 2016 年 04 月 07 日Utilization of excess wind power in electric vehicles1. Introduction Electric vehicles (EVs) raise the expectation that they can also be used as storage for intermittent electricity production from renewable energies (wind and solar) .This was mentioned as early as 2002( Kempton and Letendre ,2002) and also found its way into the energy concept of the German Federal Government (BMWi and BMU,2010).To investigate the effects of a fleet of EVs in Germany,the NET-ELAN project was initiated,funded by the German Federal Ministry of Economics and Technology.It covers abroad field of topics: Development trends of the electric grid and the power plant pool, development trends of future EV designs and determination of battery requirements and energy demand (Waldowski et al., 2010), scenarios of future energy supply and build-up of an EV fleet, assessment of spatial and temporal distributions of EVs connected to the grid (Linssen et al., 2011), grid integration of EVs with regard to feasibility, energy demand (Hennings and Linssen, 2010), emissions, and cost aspects (Bickert et al., 2011), including battery durability (Gunther et al., 2010). The project final report is published as a book(in German) (Linssen et al.,2012). This article describes the assessment of future wind power availability for charging EVs. These assessments also rely on results from the other project parts which are not described in detail here .We start with the general grid load and wind power production. The energy demand and the usage and charging of EVs are determined,and finally the energy balance for the scenario years 2020 and2030 is assessed .The potential for wind energy production and usage is first assessed with the assumption of unlimited transfer capabilities of the grid. In chapter 7 the grid limitations are addressed, the details of which are published separately (Mischinger et al., 2012). 2.Scenario This publication aims to assess the effects of a given fleet of EVs rather than predicting the probable EV deployment, therefore the build-up of a fleet of EVs is postulated.The total number of EVs is assumed tobe1millionin2020and6millionin2030,as aimed at by the German Federal Government(BMU,2011). The assumed development of the energy system is based on the objectives of the Energy Concept 2010 of the German Federal Government (BMWi and BMU, 2010), supplemented by the nuclear energy phase out decreed in 2011. Given these objectives, the power plant and wind turbine capacities installed in 2020 and 2030 are derived from calculations with the energy system model IKARUS (described e. g. in (Linssen et al., 2012).The offshore capacities assumed in the NET-ELAN scenario are approximately reached if each offshore project for which an application was submitted(dena, 2011) will be finished within two years after planned start of construction.The wind turbine capacities in the NET-ELAN scenario are shown in Table 1. For comparison, Table 1 also shows the capacities in the base scenario in the concretisation of the Energy Concept 2010 by (Nagl et al., 2010; Schlesinger et al., 2010). The dena website also provides the locations of the existing and planned wind parks. For each wind park assumed to be in operation in 2020 (2030), the wind speeds measured at the nearest of the measuring platforms FINO 1 to 3 (FINO platforms, 2012) are used to assess the potential wind power production. Table 1 also shows the allocation of installed wind park power to the three FINO locations. 3.General grid load and wind power production To calculate the fluctuations of the wind power production,the electricity demand and the charging demand of EVs,a time dependent model with at least hourly resolution is required. To assess the time series of the grid load and electricity generation in 2020 and 2030, the exact approach is separately assessing the time series of the power generation from photo- voltaic, wind, other renewables, and power consumption, and extrapolating each of them to 2020 and 2030. As some of these values were not available, an approximate approach is chosen: The assessment is based on data from the years 2007 and 2010, since the year 2007 is an example of a good wind year(wind index 106%)and 2010 of a weak wind year(windindex74%,source: (Bundesverb and WindEnergie,2012), verified by our own calculations with the data from German transmission system operators(TSOs). The time series of onshore wind power production for 2007 and 2010 are taken from the data supplied by the German TSOs, available from their websites(50Hertz Transmission,2011a; amprion, 2011a; TenneT,2011a; TransnetBW,2012a). The offshore wind power production in 2007and 2010 was neglectable.The time series of “vertical grid load” for 2007and2010aretakenfrom the data supplied by the German TSOs,available from their websites (50Hertz Transmission, 2011b; amprion, 2011b; TenneT, 2011b; TransnetBW, 2012b). The vertical grid load is defined as the total power transferred from the transmission grid to distribution grids and consumers.Upto2012 nearly all renew able power sources(including wind farms)were connected to distribution grids (110kVandlower, Table2, source: our own evaluation of (Engel, 2012), so the vertical grid load is the consumption minus production from renewables (minus production from small scale conventional plants).By adding the wind power to the vertical grid load, time series are derived which are independent from wind power production. Because charging at night is the focus of the analysis, photovoltaic production can be neglected. The time series of onshore wind power in 2020 and 2030 are extrapolated from the 2007 (2010) time series by the ratio of installed onshore wind turbine capacity.The time series of the offshore wind power in 2020 and 2030 are derived from the time series of the wind speed measured in 2007 and 2010 on the offshore measuring platforms FINO 1 to3 (FINO platforms, 2012) in 90m above sea level (hub height of typical offshore wind turbines) which are available from the FINO database1 (BSH, 2011). To each offshore wind park the wind speed of the nearest FINO measuring platform is assigned. Table1 shows how the wind park capacities areas signed to the three FINO locations.The electrical power available from the wind turbines is calculated from the wind speeds using a typical power curve for offshore wind turbines and multiplied by the off shore wind turbine capacity in 2020 and 2030. This derivation of the future wind power production in the NET-ELAN project is basically similar to the derivation in the dena Grid Study II (dena, 2010). Although the dena Grid Study II uses a more detailed modelling, the duration curve of the wind power production modelled in NET-ELAN is in quite good agreement with that in the dena Grid Study II (Fig. 1). 4.Energy demand of electric vehicles The specific energy consumptions of the EVs were estimated using detailed mathematical models of the cars,performing the Artemis and some measured real-world driving cycles,including consumption of ancillary systems and losses in the battery and the charger. The estimated energy demands for the Artemis driving cycle are close to those for the measured real-world driving cycle “commuter” and used for assessing the energy drawn from the grid. Three EV sizes were modelled:mini, subcompact, and compact, and three drive train concepts: pure battery vehicles (BEV) with a driving range of 120 km,EV with range extender (REEV) with an electrical driving range of 50 km (in charge depleting mode, CDM) and plug-in hybrid EV (PHEV) with an electrical driving range of 30 km (CDM). The BEV is limited to a daily driving distance of 120 km,the REEV and PHEV cover distances above the electrical range by their internal combustion engines(i.e.in charge sustaining mode).The energy demands(Table3) include a decrease over the manufacturing year due to technical improvements and the penetration of new vehicles in the fleet. The average daily driving distance of the EV was derived from the distribution of daily driving distances of privately used passenger cars from the statistical survey “Mobility in Germany 2008” ( infas and DLR, 2009). Some investigations make assumptions on future EV usage,e.g. (Metz and Doetsch,2012) assume that only cars with a yearly mileage of 12,500 to 20,000km will be substituted by an EV.However,future EV usage is influenced by more than just economic criteria and could be higher or lower than todays, so it is here assumed that driving distances of future EVs will besimilar to todays average cars. With these assumptions the total energy demand of 6 million BEVs in 2030 is 10.7 TWh/a, in contrast to 17 TWh/a in (Metz and Doetsch, 2012), partly because all cars are taken into account, including those with lower yearly mileage, partly because of the lower energy demand per km. As the REEV and PHEV cover daily distances above 30 km or 50 km with their ICE,the fleet energy demand with shares of BEV, REEV and PHEV as in Table3 is lower,about 9.8TWh/a. 5.Time dependent usage and charging of electric vehicles In the project, only home charging is modelled. This was decided for the following reasons: Grid interaction is only possible when the EV is parked. Although charging on-the-road seems technically possible (Yu et al., 2011; Shwartz, 2012), costs are expected to be prohibitive. A charging connection must be available where the EV is parked. The car user must connect the EV to the grid. Also here, wireless (inductive) charging is technically possible (BBC News, 2012) but assumed not to be generally applied because of high costs. The evaluation of the German nationwide survey of driving habits “MiD 2008” revealed that 92% of the daily driving distances can be covered purely electrically with a BEV and 75% with a REEV if the battery is only charged once a day after returning from the last trip of the day. In the case of urban Driving profiles measured in the project,these shares are 95% and 88%. Additional charging during the day increases these shares only marginally. The survey “MiD 2008” also indicates that the cars are parked at home for the majority of time(Metz and Doetsch, 2012) come to the same conclusion), and that the majority of privately used cars have a dedicated parking or garage near the home. That allows a private charging connection to be established with low costs, whereas public charging stations are costly (Schroeder and Traber, 2012). Connecting the EV to the grid is an extra effort for the user, so the user may not be willing to do this if it is not required for his own driving requirements.Several publications assume that the EV is connected to the grid whenever it is parked (Capion, 2009; Ekman, 2011), however the same article(Capion, 2009) admits that this is unrealistic.At least the benefit from connecting must justify the effort,therefore (Rehtanz and Rolink, 2009) assume that the EV is connected to the grid only if parked for longer than 1 h. Itis therefore assumed here that the EV is connected to the grid only after returning home from the last trip of the day and disconnected just before starting the first trip of the next day. For example(Dallinger etal.,2011) make a similar assumption. While being connected, charging can either be uncontrolled (“dumb”), which means that charging starts as soon as the EV is connected to the grid and ends when the battery is fully charged, or it can be controlled in various ways. Up to 2020, the charging power at home is assumed to be 3.3 kW which is the maximum active power available at a standard 230 V 16 A connection with a power factor of 0.9 allowing for the non-sinusoidal current drawn by the charger. In 2030, the availability of three-phase charging with 9.9 kW is assumed. In all of the modelled car types this charging power is within the design limits of the battery. For uncontrolled charging, only a part of the EVs are charging at the same time,because they return home at different times, therefore the maximum grid load for 1 million EV in 2020 is 700 MW (Fig. 2), in contrast to 3300 MW if charging of all EVs would start at the same time. But this maximum of the charging load will occur at about 6 pm,when at winter time also the other grid loads are at maximum. That can cause problems particularly for the distribution grid,described in detail in the final report (Linssen etal.,2012).The simplest mode of controlled charging is shifting the charging into off-peak times.The grid load minimum in Germany is between about midnight and 6 am.In order to achieve a nearly constant charging load between 0 and 6 am the statistically distributed charging times ranging from some minutes to 6.4 h (for the BEV full driving range of 120 km) must be taken into account. A very simple control algorithm could be as follows: The 15% of the EVs having a charging need of 3 h or more start charging at midnight. Charging of each of the 27% of EVs needing 1.5 to 3 h starts at a time so that charging is finished at 6 am.The charging times of the 58% of EVs needing less than 1.5 h are evenly distributed between midnight and 4 am.The resulting course of the share of simultaneously charging EVs over time is not perfectly even, ranging from 22% to 31% (Fig. 3), but much better than a simultaneous start of all charging (100%) at midnight. With a charging power of 9.9 kW (assumed for 2030), all charging times are below 2 h and can be suitably distributed between 0 and 6 am, giving a smooth grid load. 6.Energy balance without grid restrictions Because of its statutory priority, all electric power from renew- able energies is consumed unless its production exceeds the consumption (including possible export) or the grid stability requires its limitation. As long as all renewable power is already utilized in other loads,the additional load of EVs must be satisfied by increasing the production of conventional power plants. Renewable power is only available for charging EVs if this power could not be used otherwise. The amount of excess renewable power depends not only on the renewable power production and the power consumption but also on the amount of conventional power required to stabilize the grid (so-called must-run capacity). The dena Grid Study I (dena, 2005) assessed that in 2020 with an installed wind power capacity of 48 GW, 20 to 30 GW of conventional power plant production are needed to be able to supply negative control power (that is power which can be reduced when needed for balancing production and consumption). The FGH assessed that currently (2012 to 2014) in the German grid 8 to 25 GW of conventional power plant production must run to be able to control the active power balance and 4 to 20 GW for delivering reactive power (FGH et al., 2012). It is assumed here that 20 GW of conventional power production are needed to ensure grid stability. To show the impact of the must-run capacity, the results for zero must-run are pointed out, too. Fig. 4 shows the distribution of potential excess energy from wind power in the hours between midnight and 6 am of each night, for the year 2030. In a good wind year (solid lines) with 20 GW must-run power, excess energy is available in 70% of the nights,and it meets the daily(MoFr)energy demand of 6 million EVs (dotted line) in 50% of the nights.On the other hand, if no must-run power is required, excess energy is available in only 20% of the nights and meets the EV demand in 8% of the nights.The available excess energy is even less for a weak wind year (dashed lines). The utilization of wind power is limited by the charging demand of the vehicles,i. e. each night only as much wind power can be charged into the batteries of the vehicles as was discharged by driving during the past day (dotted line).The capability of the vehicles to utilize wind power could be increased if the battery would not be fully charged in nights with low wind, but that would mean a decrease of available driving range which will probably not be accepted by the vehicle users. Fig. 4 shows only the energy balance of each night. As the excess wind power is not evenly distributed over the night hours and the charging power of the EVs is limited, the excess wind energy which actually can be utilized by EVs is even lower. The yearly sums of utilized and non-utilized wind power are shown in Fig. 5. In 2020, the effect of 1 million EVs is so small that it can hardly be seen. 6 million EV in 2030 have a noticeable but not dramatic effect and can be powered without extensions of the electric power system (described in detail in (Linssen et al., 2012). Note that in Fig. 5 “other power” only includes the power directly fed into the transmission grid (380 and 220 kV voltage level) and the total energy in this figure is lower than the total electricity consumption. In 2030 about 50% of the energy need of the EVs can be met by utilizing excess wind power, but only if 20 GWof must-run power are required for grid stabilization. If zero must-run power would be required, even in 2030 most wind power could be utilized in other loads and hardly any excess wind power is available for charging the EVs. 7.Energy balance with grid restrictions For assessing the capabilities of the transmission grid to deliver EV charging power and to absorb wind power, a model of the German transmission grid including the power plant portfolio was developed for 2020 and 2030. The details are published, see (Mischinger et al., 2012). The calculations with the grid model show that in the scenario year 2030 the limitation is more significant, 8%compared to 15% without grid restrictions,because the grid capacity does not keep up with the increased installed wind turbine power.The share of charging energy supplied by wind energy in 2030 is limited by grid bottlenecks to 30%,compared to a potential of 50% without grid restrictions. 8.Conclusions 1 million EV have hardly any effect on the energy balance, 6 million have a noticeable but not dramatic effect. In the scenario,significant excess wind power is only available if it is assumed that 20 GW of conventional power is required for grid stabilization. If no minimum of conventional power is required,required,all wind poweras far as it can be transported by the transmission gridcan be utilized by other consumers,so that all charging power of the EVs must be delivered by increased production from conventional power plants. Without grid restrictions and a must-run power plant capacity of 20 GW, in the model year 2030 about 15% of the excess wind power can be utilized for charging EVs and can supply up to 50% of the energy needed by the EVs. The utilization of wind power is limited by the daily charging demand of the cars. Taking bottlenecks of the transmission grid into account, in the model year 2030 a significant amount of wind power can not be transported to the consumers, reducing the share of EV charging supplied from wind power from 50% to 30%. 在电动车中利用过剩的风能1.引言电动汽车的出现,提升了人们的预期:人们希望电动汽车可作为贮存器,贮存可再生能源(比如风能和太阳能)间歇发电所产生的电能。早在2002年,就有人提及上述想法(科普顿和勒让德,2002年),并且,这一设想,已被引入德国联邦政府的能源理念当中(宝马公司下属子公司和BMU,2010年)。为了调研德国境内电动汽车的整体情况,启动了欧洲局域网网络项目。该项目,由德国联邦经济技术部提供资金支持,涉及诸多领域的课题: 电力系统网络和电厂联营体的发展趋势 未来电动汽车设计的发展趋势以及对电池(相关指/参数)要求及能源需求的测定 未来能源供给以及建立电动汽车车队的设想 与电网连接的电动汽车的空间分布与时间分布(林森等,2011年) 电动汽车并网涉及的相关事项,包括可行性,能源需求(海宁思和林森,2010年),排放及包括电池耐久性(甘特等,2010年)在内的成本(伯克特等,2011年)问题。该项目的最终报告已(在德国)印刷成书并出版发行(林森等,2012年)。本文记述了未来风力发电用于电动汽车充电的有效性的评估。评估的参照标准,是其他项目中的部分结果,而这些内容并未在本文中有详细地描述。开始阶段,我们采用的是常规的电网负荷和风力发电。我们测定了能源需求,确定了电动汽车的使用和充电方法。在最后阶段,我们对2020年和2030年设想所涉及到的能源平衡问题进行了评估。我们假定电网的传输能力是无限的,在这一前提下,首先对风能发电的潜力和利用进行了评估。在第七章中,对电网的局限性进行了探讨,其中的细节问题并未收录,而是另行发布。(米思阁等,2012年)2. 设想本文旨在对设定的电动汽车车队所产生的影响进行评估,而不是为了预测电动汽车的部署与规划,因此我们会假定建立一支电动汽车车队。该车队的汽车数量,到2020时,假定为100万辆,到2030年时,假定为600万辆,而这两个数值,也正是德国联邦政府的预期目标。对能源系统发展的假定,是建立在德国联邦政府(宝马公司下属子公司和BMU,2010年)所提出的2010年能源理念这一基础之上的,并且,也考虑到了2011年所颁布的逐步淘汰核能的规定。在设定了上述目标的前提下,到2020年时,所建立的发电厂的数量和风力发电能力的大小,是利用IKARUS能源系统模型测算所产生的结果。(描述见于.文章中,比如(林森等人所著文章中,2012年)。如果每一个应用得以提交并用于每个离岸项目,那么在欧洲局域网网络情境下,离岸生产能力的目标大致可以实现,并且在计划建设开工后的两年内,得以完成。另外,欧洲局域网网络情境下的风力发电能力的大小,请参见表1。为了便于对比,表1中亦展现了基于(由那吉尔等,于2010年;施莱辛格等人,于2010年,提出的)2010年能源理念具体化目标的,基础情境下的生产能力。Dena网上,也列出了现有的和计划建设的风力发电园的位置。这些风力发电园投入使用的时间,假定在2020年(或是2030年)。利用与发电园距离最近的FINO1至3号测量平台(FINO 平台,2012年)来进行风速测试,并利用测试结果,来评估潜在的风力发电能力。表1也展示了Fino1至3号测试平台所配属的,已建立的风力发电园的位置。3. 常规电网负荷和风力发电为了测算风力发电的波动值,电动汽车的电流要求以及充电要求(指数),需要建立一个时变模型,该模型要包含解决方案,方案产生频率不低于每小时/一次。为估算2020年和2030年的电网负载和电流生成的时间数列,采用精确方法,分别测算了光电池发电,风力发电以及其他可再生能源发电的时间数列和能源消耗,并推算了到2020年和2030年时上述参数的数值。其中一些数值,过去无法获得,所以就选用了以下的近似方法:估值是建立在2007年至2010年的数据基础之上的,其原因在于,2007年是风力较大年(风力指数达到了106%),而2010年是风力较小年(风力指数只有74%),数据来源是:(Bundesverb和WindEnergine, 2012)。上述的数据,已经过我们自有的估算证实,估算所使用的数据来自德国传送操作系统(简称TSOs)。2007年和2010年两年的近岸风力发电的时间序列,其来源为德国传送操作系统(TSO),数值见于该系统的数家网站(50赫兹,传送,2011a; 安普瑞恩,2011a;特尼特,2011a; 传送带BW,2012a) (译者注:50Hertz(50赫兹) ,amprion(安普瑞恩),TenneT(特尼特),TransnetBW(传送带BW), 为德国四大输电系统运营商)。2007年和2010年两年的离岸风力发电数值已忽略。2007年和2010年两年的垂直电网负载的时间序列,其来源为德国传送操作系统(TSO),数值见于该系统的数家网站(50赫兹,传送,2011b; 安普瑞恩,2011b;特尼特,2011b; 传送带BW,2012b)。垂直电网负载的定义为:从传输电网至配电电网和消费者处所传输的总电量值。截至2012年,几乎所有的可再生发电资源(包括风力电场在内),都已与配电电网相连接(100千Vandlower(译者注:Vandlower, 可能是电量计量单位,或许类似中国的千瓦时,但未查出具体含义),表2,来源为我们自己的估值(安吉尔, 2012))因此,垂直电网载荷就是用消耗的电量减去可再生能源产生的电量(不含小规模传统发电厂所发出的电量)后,所得到的数值。将风力发电数值与垂直电网的负载相加,即可得到时间序列的数值,这一数值与风力发电的数值,不相关联。因为夜晚充电是解析的重点,所以光电池所产生的电量可以忽略不计。2020和2030两年的近岸风力的时间序列的推算,是依据2007年(2010年)的时间序列而开展的,而后两者(07和10年)的时间序列,则是以建成的近岸风力涡轮机容量为基础而确定的。2020和2030两年的离岸风力的时间序列,源自2007年和2010年的风速测试的时间序列的结果,而后两者的(指07年和10年)时间序列结果,是利用建在海平面90米以上(此高度为典型的离岸风力涡轮机的轮毂高度)的FINO1至3号测量平台得出的,这三个测量平台的数据则来自FINO 1号数据库(博世,2011年)。距离每个离岸风电场最近的FINO测量平台的风速已经确定。表1的内容,是三个FINO平台的定位是如何与风电场的产能地区相对应的。而风力涡轮机所产生的电能的测算依据,是风速。这里的风速,指的是利用典型的功率曲线,测算出离岸涡轮机的相关数值,再乘以2020年和2030年的离岸风力涡轮机的容量所得出的结果。欧洲局域网网络项目中的未来风力发电值的导出方法,类似于dena网站上的二期电网研究(dena网站,2010年)所使用的导出方法。尽管后者所利用的是一个更加精细的建模方式,但在欧洲局域网网络项目中,风力发电的历时曲线所使用的建模方式,与dena网站上的二期电网研究所使用的建模方式,是基本一致的。(图/表1)4电动汽车的能源需求使用汽车的详细数学模型估计具体的电动汽车的能源消耗,执行阿耳特弥斯和测量一些真实的驾驶周期,包括辅助系统消耗和电池和充电器的损耗。阿耳特弥斯驾驶周期估计的能源需求接近真实上班族的驾驶的周期测量并且通过评估供电网络可以适用。三个电动汽车尺寸建模:迷你,微型车,紧凑,和三个传动系概念:纯电池汽车(BEV)的驾驶里程为120公里,电动汽车与增程器(REEV)电子系统可行驶的50公里(负责消耗模式,CDM)和插电式混合动力电动汽车(PHEV)的电气系统可行驶30公里(CDM)。BEV仅限于日常驾驶120公里的距离,内燃机上方的REEV和PHEV覆盖距离。(Table3)包括制造一年由于技术改进和新汽车的普及率的快速变化使得能源需求在减少。平均每日驾驶电动车的距离是来源于日常驾驶距离的分布由2008年德国“Mobility”统计调查使用的私人轿车得出。通过一些调查做出假设未来电动汽车的使用,例如:Doetsch(梅斯和,2012)认为只有汽车每年12500到20000公里的里程将由一个电动汽车取代。然而,未来电动汽车的使用不仅仅是受经济条件和可能高于或低于今天的,所以在这里假定未来电动汽车的行驶距离将比今天的普通汽车更短。与这些假设的总能源需求600万2030年成为10.7 TWh /a,与17 TWh /a(梅斯和德意茨创作,2012),部分原因是考虑到所有的汽车,包括年度里程较低,部分原因是每公里较低的能源需求。REEV和PHEV覆盖日常距离超过30公里或50公里的冰,与BEV能源需求进行共享,REEV和PHEV Table3较低,大约9.8TWh /a。5时间取决于使用和电动汽车的充电在这个项目中,只有回家充电是模仿。这个决定是出于以下原因:网格交互只能当电动车停放。
温馨提示:
1: 本站所有资源如无特殊说明,都需要本地电脑安装OFFICE2007和PDF阅读器。图纸软件为CAD,CAXA,PROE,UG,SolidWorks等.压缩文件请下载最新的WinRAR软件解压。
2: 本站的文档不包含任何第三方提供的附件图纸等,如果需要附件,请联系上传者。文件的所有权益归上传用户所有。
3.本站RAR压缩包中若带图纸,网页内容里面会有图纸预览,若没有图纸预览就没有图纸。
4. 未经权益所有人同意不得将文件中的内容挪作商业或盈利用途。
5. 人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对用户上传分享的文档内容本身不做任何修改或编辑,并不能对任何下载内容负责。
6. 下载文件中如有侵权或不适当内容,请与我们联系,我们立即纠正。
7. 本站不保证下载资源的准确性、安全性和完整性, 同时也不承担用户因使用这些下载资源对自己和他人造成任何形式的伤害或损失。
提示  人人文库网所有资源均是用户自行上传分享,仅供网友学习交流,未经上传用户书面授权,请勿作他用。
关于本文
本文标题:汽车电控液压助力转向系统设计
链接地址:https://www.renrendoc.com/p-22889753.html

官方联系方式

2:不支持迅雷下载,请使用浏览器下载   
3:不支持QQ浏览器下载,请用其他浏览器   
4:下载后的文档和图纸-无水印   
5:文档经过压缩,下载后原文更清晰   
关于我们 - 网站声明 - 网站地图 - 资源地图 - 友情链接 - 网站客服 - 联系我们

网站客服QQ:2881952447     

copyright@ 2020-2025  renrendoc.com 人人文库版权所有   联系电话:400-852-1180

备案号:蜀ICP备2022000484号-2       经营许可证: 川B2-20220663       公网安备川公网安备: 51019002004831号

本站为文档C2C交易模式,即用户上传的文档直接被用户下载,本站只是中间服务平台,本站所有文档下载所得的收益归上传人(含作者)所有。人人文库网仅提供信息存储空间,仅对用户上传内容的表现方式做保护处理,对上载内容本身不做任何修改或编辑。若文档所含内容侵犯了您的版权或隐私,请立即通知人人文库网,我们立即给予删除!