电动汽车电池管理系统的开发研究

本文针对电动汽车电池管理系统中的电池SOC估算和均衡电路开展研究工作。利用安时积分法设计SOC估算电路,采集电池电压进行数据分析,达到实时精确监测反馈电池SOC的功能;采用基于电感的非耗散型均衡电路控制策略,实现电池间能量均衡。在Matlab中完成了电路的仿真,通过硬件设计及电路制作验证SOC及均衡效果。结果表明,本系统能实现精确测定电池残电量和单体电池间的能量均衡,能量损耗小、工作效率高。     

莫让野蛮生长挑战公共安全 见微知著,标准先行

正目前我国电动汽车安全问题主要体现在电池使用、材料构成和充电安全方面,上下游产业发展不平衡、企业盲目重量轻质是造成这些问题的主要因素。此外,监管存在漏洞、政府相关政策不全,保障电动汽车安全必须在生产过程中严格执行安全要求和标准。随着电动汽车产业发展迈入培育的关键时期,电池等自主创新技术还有待进一步提高,如何确保电动汽车产业安全运行和健康发展成为当前面临的重大课题。据悉,为促进我国电动汽车行业标准的完     

英国某研究团队认为可以准确预测电动汽车中的电池寿命

对于汽车行业来说,提高电池性能和整体使用寿命,具有革命性意义.在英国,由两家电动汽车制造商、若干学者和一家电池分析专业公司组成的团队,正在开展一项电动汽车电池研究项目.该项目旨在预测电池寿命,据称已取得成功.     

纯电动公交车示范项目

在本项目中,临沂市公交总公司采用了铝合金全承载车身、三相异步电机驱动系统、磷酸铁锂动力电池组的纯电动车作为公交车,依靠当地电动汽车生产企业提供的车辆技术支持,从2010年2月起,先后在5条公交线路上进行了SDL6120EVG纯电动车的示范运行。通过合理使用电池、强化电池保养、加强驾驶员培训等管理手段。到目前为止,单车平均运行2万多公里,车辆运行平稳,节能环保效果良好。     

百人会电动汽车安全问题研讨会召开 提高电动汽车安全性

正3月27日,中国电动汽车百人会召开了"电动汽车热点问题系列研讨会Ⅰ",对电动汽车安全问题进行探讨和分析。目前国内电动汽车安全问题主要体现在电池使用、材料构成和充电安全方面。上下游产业发展不平衡、企业盲目重量轻质是造成这些安全问题的主要因素,此外,监管监控存在漏洞、政府相关政策不全也是原因之一。因此,电动汽车相关企业必须严抓质量环节、进行技术创新、加强监管监控、不能冒进求成;政府相关部门也应重视电动汽车安全问题,在相关政策法规上进行逐步完善,确保各部门之间协同合作,促进电动汽车行业有序、健康、稳定的发展。     

纯电动小客车用锂动力电池温度特性实验研究

本文测试和分析了纯电动小客车用锂动力电池在不同温度下的放电、充电、放电容量、欧姆内阻和表面温升性能,实验结果表明,低温对锂单体电池性能的影响比较显著,锂单体电池在低温下各项性能指标存在变差趋势。为保证锂单体电池的正常使用,建议增设电池包预加热系统以便提升锂单体电池性能。     

纯电动汽车应用现状分析及策略探讨

通过对知豆纯电动汽车的调查实践,文章简述了纯电动汽车的优势及其电驱动系统机构,分析了纯电动汽车的应用现状,提出了纯电动汽车应用存在的价格较高、基础设施不完善、电池性能及能量管理有待优化等问题。在此基础上,提出了要继续强化纯电动汽车的基础研究、加快充换电站等基础设施建设和政府政策继续引导支持的建议。     

汽车新节能技术的展望

文章介绍了目前国际上几种比较新颖的节能技术,诸如能量收集与储存新技术、汽主行驶中的能量回收再生技术,电容器和电池二次电池能量回收再生技术、飞轮电动汽车的能量回收与利用技术等等。     

电动汽车运行阶段碳排放因子影响因素研究

电动汽车全生命周期可分成生产、运行、拆解回收三个阶段,本文在分析三个阶段碳排放内涵的基础上,重点研究了电动汽车运行阶段的碳排放因子,分析了发电结构、电池容量、续航里程三个因素对运行阶段碳排放因子的影响机理。研究结果表明：发电结构是影响电动汽车碳排放因子的重要因素,2020年中国、美国电动汽车运行阶段碳排放因子分别为87.99、51.49 gCO2/km,中国约为美国的1.7倍,主要原因是中国的煤电占比远高于美国,且美国可再生能源发电比例较高;在我国2020年的发电结构下,电池容量为20 kW·h的电动汽车续航里程从100 km提升至200 km后,其运行阶段碳排放因子从121.36 gCO2/km降至60.68 gCO2/km。因此,我国应大力发展可再生能源发电技术,不断优化电力结构,为降低电动汽车碳排放因子打下基础;同时要不断突破电池技术难题,优化电池性能,提高续航里程,从而有效降低电动汽车运行阶段的碳排放因子。     

基于专利数据的纯电动汽车发展分析

该文以对全球纯电动汽车专利申请进行检索的结果为依据,分析了全球纯电动汽车专利申请的增长趋势、专利申请的技术构成态势,并从专利申请国、专利申请目标国方面进行了分析,着重分析了我国技术水平与国际上的差距,列举了纯电动汽车核心技术即电池的发明点,为我国新能源技术的研究开发提供专利信息服务。     

Survey of R&D in PRT systems

A survey of research and development in advanced transit has been made by Chalmers University of Technology in Gothenburg in cooperation with Trans21 in Boston. Summary findings are reported for fourteen academic research programs and ten development programs for PRT. An earlier version of this paper was presented at the International Conference of PRT and other Emerging Systems held in Minneapolis in 1996.     

The Impact of Container Type Diversification on Regional British Port Development Strategies

Abstract

Despite a concentration of container traffic in the southeast of the UK over the last few decades, regional ports are attempting new development strategies to capture or retain specific traffic segments. These include intra-European short-sea traffic and a potentially increasing feeder market. These trends are reflected in the movement of different container types, which result in a number of planning challenges related to changing infrastructural and operational requirements. This paper uses highly disaggregated data on container type movements to address three issues that can inform these planning challenges. First, the imbalance of trade resulting in empty container repositioning; second, the requirement for gauge-cleared rail routes to cater for the increasing proportion of high-cube containers; and third, the specialisation of European short-sea traffic at secondary UK ports. The results reveal the disproportionate repositioning of empty containers at Scottish ports and the importance of 45?ft, high-cube and pallet-wide containers at regional ports, highlighting their focus on intra-European short-sea traffic and raising difficulties relating to their lower quality of landside infrastructure (particularly rail) in comparison to the large south-eastern ports. The potential repercussions on hinterland infrastructure development raise questions about both public and private sector responses to regional port development.     

管道风险分析指数评分法中分值调整初探

管道风险分析指数评分法中重要步骤之一就是确定影响管道事故因素的权重,各个管道风险因素在整个管道事故中所占的权重是不相同的。针对目前管道风险分析指数评分法基本假设之一（各因素的分值范围都是0～100分）,为了更加客观、准确、合理地反映各个风险因素对于管道事故的影响程度,提出并论述了依据层次分析法的数学逻辑性进行综合计算得出管道风险因素的权重,然后对评分法中各个因素的最高分值,根据其权重不同进行相应调整,从而增强评价者对风险因素的认识和评判能力,提高管道风险评价结果的准确性。     

A century of evolution of the accessibility concept

The concept of accessibility has acquired numerous meanings along multiple dimensions during the century of its evolution. This essay argues for the salience of two dimensions: application-based and definition-based. In its application, accessibility has incorporated positive and normative dimensions which have varied in prominence over time. In its definition, accessibility has varied between a mode of evaluation incorporating measured mobility and proximity, on the one hand, and a predefined market basket of urbanist improvements to transportation and land use systems, on the other. Advocates of the accessibility shift should emphasize both the measured approach to accessibility and accessibility’s normative side.     

天然气站往复式压缩机活塞失效分析

针对天然气站往复式压缩机活塞的断裂事故,运用失效分析方法,开展了活塞断口扫描电镜分析、能谱和金相分析。根据断口形貌的电镜和金相观察结果,结合理论知识,分析确定了该活塞发生断裂事故的主要原因,即在特定工况下该活塞的材料缺陷是造成断裂的主要因素。     

中国城市道路规划方位性问题研究

文章结合中国的传统建筑文化理念和现代科学原理,从历史文化、能源节约、环境保护、房地产定价、交通安全等多方面分析研究了城市道路在规划和设计时所应遵从的定向规则。     

Predicting queue variability to enable analysis of overload risk

ABSTRACT

Predicting the risk of traffic demands and delays exceeding critical limits at road junctions, airports, hospitals, etc., requires knowing how both mean and variance of queue size vary over time. Microscopic simulation can explore variability but is computationally demanding and gives only sample results. A computationally efficient approximation to the mean is used in many modelling tools, but only empirical extensions for variance in particular situations have been available. The paper derives theoretical formulae for time-dependent and equilibrium variance, believed to be novel and to apply generally to queues covered by the Pollaczek–Khinchin mean formula, and offering possible structural insights. These are applied in an extended approximation giving mutually consistent mean and variance estimates with improved accuracy. Tests on oversaturated peak demand cases are compared with Markov probabilistic simulation, demonstrating accuracy (R^2?>?0.99) for typical random, priority-like (M/M/1) and traffic-signal-like (M/D/1) queues. Implications for risk analysis, planning and policy are considered.     

Planning guidelines for metro–bus interchanges by means of a pedestrian microsimulation model

The big paradigm for cities nowadays is to study the movement of pedestrians at the interface between metro and bus systems – metro–bus interchanges. When these interchanges are not well designed, walking is inefficient and can be unsafe for pedestrians. This paper analyses, by means of a pedestrian microsimulation model, metro–bus interchange spaces in order to propose planning guidelines for the city of Santiago de Chile. Specific objectives are (1) to identify the variables that provide efficiency and safety in those spaces; (2) to simulate different scenarios using the pedestrian simulation model LEGION; (3) to propose planning and design guidelines for pedestrian spaces at metro–bus interchanges; and (4) to contrast the recommendations in the recently opened terminal station on Line 1 of Metro de Santiago: Los Dominicos Station.     

生命大过天

文章介绍了广西壮族自治区公路管理局开展专项行动,治理以桥梁为重点的交通基础设施安全隐患的情况,针对在役桥梁、在建桥梁和农村公路桥梁存在的安全隐患提出了相应的治理措施。