What is the market potential of plug-in electric vehicles as commercial passenger cars? A case study from Germany

Commercial passenger cars are a possible early market segment for plug-in electric vehicles (PEVs). Compared to privately owned vehicles, the commercial vehicle segment is characterized by higher mileage and a higher share of vehicle sales in Germany. To this point, there are only few studies which analyze the commercial passenger car sector and arrive at contradictory results due to insufficient driving profile data with an observation period of only one day. Here, we calculate the market potential of PEVs for the German commercial passenger car sector by determining the technical and economical potential for PEVs in 2020 from multi-day driving profiles. We find that commercial vehicles are better suited for PEVs than private ones since they show higher average annual mileage and drive more regularly. About 87% of the analyzed three-week vehicle profiles can technically be fulfilled by battery electric vehicles (BEVs) with an electric driving range of about 110 km while plug-in hybrid electric vehicles (PHEVs) with an electric range of 40 km could obtain an electric driving share of 60% on average. In moderate energy price scenarios, PEVs can reach a market share of 2–4% in the German commercial passenger car sales by 2020 and especially the large commercial branches (Trade, Manufacturing, Administrative services and Other services) are important. However, our analysis shows a high sensitivity of results to energy and battery prices as well as electric consumptions.     

基于元胞自动机的轨道交通突发客流拥堵消散演化机理研究

为保证城市轨道交通运输系统在突发客流条件下能够安全高效运营，本文基于元胞自动机建立城市轨道交通突发客流拥堵传播模型.分析突发客流量拥堵传播过程，采用状态参数集反映车站拥挤程度的多样化差异，定义更为准确合理的客流量元胞自动机演化规则.以成都市轨道交通部分线网为例，仿真设置不同量值的突发客流，研究线网客流状态的演化规律.结果表明，随着突发客流量增加，客流状态从区域拥堵演化至线拥堵的速度减缓，从线拥堵演化至点拥堵的速度保持不变或略有加快.此外，大量突发客流会引起拥堵消散速度的减缓，造成更大时空范围的区域性拥堵.     

智能网联卡车车队混合流通行能力分析方法

智能网联卡车车队有望成为网联自动驾驶率先应用的场景之一，本文针对智能网联卡车车队混合交通流通行能力开展研究。首先，以智能网联卡车车队、人工驾驶卡车及人工驾驶小汽车构成的随机混合交通流为研究对象，考虑智能网联卡车车队规模空间分布特征，分析混合交通流中10种跟驰行为类型，理论推导其概率表达式，进而构建智能网联卡车车队混合交通流通行能力的通用性分析方法。然后，考虑实际交通流运行中卡车分布的随机性，将智能网联卡车车队混合交通流分为优势流、随机流和劣势流3种态势，以此提升混合交通流通行能力分析方法的普适性。最后，选择实测数据标定的跟驰模型进行案例分析，验证理论分析方法的有效性。研究结果表明：智能网联卡车比例提高或其车队规模增大均有利于3种态势混合交通流中车辆转换系数及相对熵的减小，从而可有效提升混合交通流通行能力。不同智能网联卡车比例条件下，智能网联卡车车队随机分布最优车队规模为2~4辆，同时，优势流、随机流和劣势流3种混合交通流通行能力依次递减。研究结果揭示了智能网联卡车车队混合交通流通行能力提升的内在机理，为未来智能网联卡车车队的运营管理提供方法支撑。     

Probe vehicle data sampled by time or space: Consistent travel time allocation and estimation

A characteristic of low frequency probe vehicle data is that vehicles traverse multiple network components (e.g., links) between consecutive position samplings, creating challenges for (i) the allocation of the measured travel time to the traversed components, and (ii) the consistent estimation of component travel time distribution parameters. This paper shows that the solution to these problems depends on whether sampling is based on time (e.g., one report every minute) or space (e.g., one every 500 m). For the special case of segments with uniform space-mean speeds, explicit formulae are derived under both sampling principles for the likelihood of the measurements and the allocation of travel time. It is shown that time-based sampling is biased towards measurements where a disproportionally long time is spent on the last segment. Numerical experiments show that an incorrect likelihood formulation can lead to significantly biased parameter estimates depending on the shapes of the travel time distributions. The analysis reveals that the sampling protocol needs to be considered in travel time estimation using probe vehicle data.     

依靠技术手段,防止客车电气火灾

铁路客运量的剧增给铁路的安全运输生产提出了更高的要求 ,不断增加的高技术装备使得电气系统发生火险的可能性在不断增大 ,旅客列车安全用电与防火问题也面临着严峻的挑战。为此 ,必须加强对空调客车电气系统的制造、维修、保养中的防火安全意识 ,以及对火灾事故的预想和防范 ,坚决杜绝此类事故的发生 ,以保证旅客列车的绝对安全     

客车行车安全监测系统中走行部节点功能校验系统的实现

为了对客车行车安全监测系统中车辆走行部节点功能进行校验 ,将以往典型试验的采样数据无失真的回放出来 ,代替车辆走行部节点的采样信号源 (传感器拾取的信号 ) ,车辆走行部节点装置对输出的波形进行采样、预处理和数据分析 ,方便实用     

发展重载运输对编组站既有调速设备提出的新要求

文章介绍了发展重载运输以后对编组站作业带来的各种影响,并提出应对既有的调速设备和作业方式进行改造和改进来适应这一新变化.     

地铁车体结构垂向总载荷和纵向力取值的探讨

针对我国地铁车辆车体强度载荷值不统一的现状 ,通过与国内外地铁强度规范的比较及计算分析 ,并考虑安全性和经济性 ,提出我国地铁车体的垂向载荷和纵向力的建议值     

运行旅客列车隧道火灾模型实验及数值模拟

旅客列车在隧道内发生火灾时 ,火灾烟气运动状况直接影响旅客的人身安全。本文利用风洞提供的流场模拟列车在隧道中运行的速度场 ,制作了 1∶5的旅客列车卧铺车厢 ,在车厢模型中加入等比例的火灾载荷 ,对运行旅客列车在隧道内发生火灾进行了缩尺模拟实验 ,并用商业CFD软件PHOENICS 3 .5对实际情况进行了简化数值模拟 ,研究了不同情况下旅客列车火灾特征及火灾中烟气蔓延规律 ,提出了满足火灾救援和旅客人员疏散的要求。     

IGBT模块在TGV-A高速列车动力车辅助逆变器上的应用

在确保TGV的运营和提高可靠性的前提下,法国国营铁路(SNCF)寻求一种革新、耐用、可靠和经济的器件来更换车载功率设备中的GTO.文章介绍了保持TGV-A动车的车载环境与静止变流器使用IGBT技术的兼容性.重点介绍了在一个30 kVA的辅助逆变器上开展的相应工作,为改造任务制定的技术规范,并在满足热要求的同时实现与现有机械接口的匹配,目的是提高运行的可靠性,优化开关性能,以满足CEM的要求.研究工作成功实现了产品的工业化,这使机车车辆工程技术部门的技术服务能满足更换例如GTO之类的功率器件的需要.