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971.
This study investigates the energy consumption impact of route selection on battery electric vehicles (BEVs) using empirical second-by-second Global Positioning System (GPS) commute data and traffic micro-simulation data. Drivers typically choose routes that reduce travel time and therefore travel cost. However, BEVs’ limited driving range makes energy efficient route selection of particular concern to BEV drivers. In addition, BEVs’ regenerative braking systems allow for the recovery of energy while braking, which is affected by route choices. State-of-the-art BEV energy consumption models consider a simplified constant regenerative braking energy efficiency or average speed dependent regenerative braking factors. To overcome these limitations, this study adopted a microscopic BEV energy consumption model, which captures the effect of transient behavior on BEV energy consumption and recovery while braking in a congested network. The study found that BEVs and conventional internal combustion engine vehicles (ICEVs) had different fuel/energy-optimized traffic assignments, suggesting that different routings be recommended for electric vehicles. For the specific case study, simulation results indicate that a faster route could actually increase BEV energy consumption, and that significant energy savings were observed when BEVs utilized a longer travel time route because energy is regenerated. Finally, the study found that regenerated energy was greatly affected by facility types and congestion levels and also BEVs’ energy efficiency could be significantly influenced by regenerated energy. 相似文献
972.
程琳琳 《广东交通职业技术学院学报》2011,10(4):32-36
感兴趣区域提取技术在图像分析与处理领域中起着重要的作用。文中对现有的感兴趣区域提取技术进行了深入探讨,详细研究了当前几种较具代表性的感兴趣区域提取技术,并对其提取效果做了评价。总结了它们的优缺点以及适用场景,为用户选取合适的感兴趣区域提取方法,提供了实验依据。 相似文献
973.
974.
为减小再生制动能量的冲击性和间歇性,提出一种基于微电网的再生制动能量回馈系统,利用城轨出入口电动汽车的闲置时间,发挥其储能特性和可调度特性,平抑制动能量的冲击性和间歇性,为车站提供稳定的绿色电力。为使所提微电网再生制动能量回馈系统的安全可靠工作,设计了再生制动能量回馈控制,逆变器恒功率控制及电动汽车充放电控制,同时考虑到电动汽车充放电受荷电状态约束,提出了一种基于滞环比较器的协调控制方法,以实现再生制动能量回馈控制,逆变器恒功率控制的同时避免电动汽车过充或过放。最后搭建Simulink仿真模型对所提微电网再生制动能量回馈系统进行验证,结果表明:所提运行控制和协调控制方法是有效可行的,对再生制动能量的利用具有应用和研究价值。 相似文献
975.
为节约能源,改善环境,混合动力汽车应运而生。分析混合动力技术的工作原理。分别介绍混合动力汽车的分类及代表车型,混合动力汽车的普及和政策扶持情况,标准制定工作。并介绍混合动力汽车在中国市场和国际市场上的发展。 相似文献
976.
In this paper, airline energy efficiency is divided into two stages: Operations Stage and Carbon Abatement Stage. This new two-stage operating framework is a modification of existing ones. Then the model, Network SBM with weak disposability, is presented to evaluate the efficiency of 22 international airlines from 2008 to 2012. The results show that: (1) Most airlines’ energy efficiencies have not declined in the period. (2) The average efficiency of European airlines is higher than that of non-European airlines. (3) Non-European airlines have smaller advancements in efficiency score than European airlines. (4) Most airlines’ efficiencies in Operations Stage are higher than Carbon Abatement Stage. 相似文献
977.
The United States transportation sector consumes 5 billion barrels of petroleum annually to move people and freight around the country by car, truck, train, ship and aircraft, emitting significant greenhouse gases in the process. Making the transportation system more sustainable by reducing these emissions and increasing the efficiency of this multimodal system can be achieved through several vehicle-centric strategies. We focus here on one of these strategies – reducing vehicle mass – and on collecting and developing a set of physics-based expressions to describe the effect of vehicle mass reduction on fuel consumption across transportation modes in the U.S. These expressions allow analysts to estimate fuel savings resulting from vehicle mass reductions (termed fuel reduction value, FRV), across modes, without resorting to specialized software or extensive modeling efforts, and to evaluate greenhouse gas emission and cost implications of these fuel savings. We describe how FRV differs from fuel intensity (FI) and how to properly use both of these metrics, and we provide a method to adjust FI based on mass changes and FRV. Based on this work, we estimate that a 10% vehicle mass reduction (assuming constant payload mass) results in a 2% improvement in fuel consumption for trains and light, medium, and heavy trucks, 4% for buses, and 7% for aircraft. When a 10% vehicle mass reduction is offset by an increase in an equivalent mass of payload, fuel intensity (fuel used per unit mass of payload) increases from 6% to 23%, with the largest increase being for aircraft. 相似文献
978.
A novel flywheel energy storage(FES) motor/generator(M/G) was proposed for marine systems.The purpose was to improve the power quality of a marine power system(MPS) and strengthen the energy recycle.Two structures including the magnetic or non-magnetic inner-rotor were contrasted in the magnetostatic field by using finite element analysis(FEA).By optimally designing the size parameters,the average speed of FEA results of was 17 200 r/m,and the current was controlled between 62 and 68 A in the transient field.The electrical machine electromagnetism design was further optimized by the FEA in the temperature field,to find the local overheating point under the normal operation condition and provide guidance for the cooling system.Finally,it can be concluded from the comprehensive physical field analysis that the novel redundant structure M/G can improve the efficiency of the M/G and maintain the stability of the MPS. 相似文献
979.
980.
绞吸船疏浚典型黏性土、密实粉土粉砂和钙质结核物的混合土时易糊绞刀头,且输送时易堵管。依托连云港港30万吨级航道疏浚工程,对混合土的不均匀性进行分析,从典型土的挖掘比能与船舶施工参数相关性角度,推导出连云港港混合土的特性指标与挖掘产量的计算公式,可预测复杂土的疏浚产量。结果表明:连云港港典型混合土由黏性土、密实粉土粉砂和钙质结核物混合而成,具有多种土质特性;利用推导出的公式预测"天虎号"绞吸船挖掘此类土的生产率,经过与实测值对比,其相对偏差在15%以下,可靠性好,可为类似工程提供借鉴。 相似文献