铁路10kV配电所改造设计若干问题探讨

铁路配电所是铁路电力供电系统的主要组成部分,既有配电所改造设计与新建配电所设计有着明显的不同,需要满足技术先进性、设备可靠性以及经济性,而且还要解决现有设备在运行过程中的问题.本文对铁路10 kV配电所改造设计中遇到的问题进行分析与讨论,并提出设计应采用的策略.     

基于dSPACE的船用异步电机矢量控制研究

为了能够反复便捷地对船用异步电机矢量控制技术进行研究,需要对整个系统进行仿真。而传统的离线仿真技术已不能满足现在系统多样的需求,而本文研究的d SPACE实时仿真技术可以很好的解决这一问题。本文首先研究船用异步电机矢量控制技术,然后针对该控制方案进行基于Simulink的离线仿真,接着搭建了基于d SPACE半实物仿真平台的船用异步电机矢量控制系统,并借助于该系统展开船用异步电机矢量控制实验,验证基于d SPACE进行船用异步电机矢量控制的可行性、实用性与便捷性。     

Air quality impacts of electric vehicle adoption in Texas

Widespread adoption of plug-in electric vehicles (PEVs) may substantially reduce emissions of greenhouse gases while improving regional air quality and increasing energy security. However, outcomes depend heavily on the electricity generation process, power plant locations, and vehicle use decisions. This paper provides a clear methodology for predicting PEV emissions impacts by anticipating battery-charging decisions and power plant energy sources across Texas. Life-cycle impacts of vehicle production and use and Texans’ exposure to emissions are also computed and monetized. This study reveals to what extent PEVs are more environmentally friendly, for most pollutant species, than conventional passenger cars in Texas, after recognizing the emissions and energy impacts of battery provision and other manufacturing processes. Results indicate that PEVs on today’s grid can reduce GHGs, NO_x, PM₁₀, and CO in urban areas, but generate significantly higher emissions of SO₂ than existing light-duty vehicles. Use of coal for electricity production is a primary concern for PEV growth, but the energy security benefits of electrified vehicle-miles endure. As conventional vehicle emissions rates improve, it appears that power grids must follow suit (by improving emissions technologies and/or shifting toward cleaner generation sources) to compete on an emissions-monetized basis with conventional vehicles in many locations. Moreover, while PEV pollution impacts may shift to more remote (power plant) locations, dense urban populations remain most strongly affected by local power plant emissions in many Texas locations.     

China’s electric car frustrations

By 2020, the vehicle population in China will likely exceed 280 million—exacerbating national energy security, urban air pollution, and traffic congestion. In response, many local and regional governments in China are pursuing an expanding array of measures to restrain growth in personal vehicle ownership and, along with the central government, reducing emissions and energy use of vehicles. One prominent strategy is the promotion of new energy vehicles, especially plug-in electric vehicles (PEVs). Large subsidies were offered—up to $27,600 (171,000 RMB) per vehicle in some regions, including almost $9200 (57,000 RMB) from the central government—which suggests that China is making a major commitment to PEVs. But sales have been meager. In 2013, only 17,600 PEVs, mostly buses and utility trucks, were sold, less than 0.1% of total civilian vehicle sales. Several factors explain the failure of PEV sales to take off: (1) protectionism by local governments; (2) uncertainty over which electric-drive vehicle technologies to promote and what consumers are willing to pay, (3) lagging investments in charging infrastructure, and (4) conservative investment behavior by automakers and battery manufacturers. The central government issued directives to local governments in late 2013 to reduce barriers to out-of-town companies, resulting in modest sales increases in early 2014, but a more coherent, broader, and effective set of policies, incentives, and strategies are needed to overcome consumer and industry resistance and the lack of charging infrastructure.     

动车组客室座椅蒙面用布研究

以动车组座椅蒙面布为研究对象,以实践应用为基础,从蒙面布的各项性能指标出发,分析动车组座椅蒙面布的综合性能要求,明确动车组座椅蒙面布今后的研究与开发方向。     

地铁车辆牵引电机异响问题及解决措施

针对某项目车辆牵引电机异响问题,介绍了故障牵引电机的调查过程,初步确认牵引电机异响的原因为牵引电机轴承出现异常;对出现异常的牵引电机轴承进行了调查,发现电机轴承出现电蚀现象;通过对电蚀轴承的进一步调查,初步确认牵引电机轴承轴端电流过大是牵引电机电蚀的原因。为解决牵引电机轴端电流过大的问题,提出了有效的整改措施,并进行了试验验证,取得了良好的效果。     

Handling performance control for hybrid 8-wheel-drive vehicle and simulation verification

In order to improve handling performance of a hybrid 8-Wheel-Drive vehicle, the handling performance control strategy was proposed. For armoured vehicle, besides handling stability in high speed, the minimum steer radius in low speed is also a key tactical and technical index. Based on that, the proposed handling performance control strategy includes ‘Handling Stability’ and ‘Radius Minimization’ control modes. In ‘Handling Stability’ control mode, ‘Neutralsteer Radio’ is defined to adjust the steering characteristics to satisfy different demand in different speed range. In ‘Radius Minimization’ control mode, the independent motors are controlled to provide an additional yaw moment to decrease the minimum steer radius. In order to verify the strategy, a simulation platform was built including engine and continuously variable transmission systems, generator and battery systems, independent motors and controllers systems, vehicle dynamic and tyre mechanical systems. The simulation results show that the handling performance of the vehicle can be enhanced significantly, and the minimum steer radius can be decreased by 20% which is significant improvement compared to the common level of main battle armoured vehicle around the world.     

Consumers’ willingness to pay for alternative fuel vehicles: A comparative discrete choice analysis between the US and Japan

This paper conducts a comparative discrete choice analysis to estimate consumers’ willingness to pay (WTP) for electric vehicles (EVs) and plug-in hybrid electric vehicles (PHEVs) on the basis of the same stated preference survey carried out in the US and Japan in 2012. We also carry out a comparative analysis across four US states. We find that on average US consumers are more sensitive to fuel cost reductions and alternative fuel station availability than are Japanese consumers. With regard to the comparative analysis across the four US states, consumers’ WTP for a fuel cost reduction in California is considerably greater than in the other three states. We use the estimates obtained in the discrete choice analysis to examine the EV/PHEV market shares under several scenarios. In a base case scenario with relatively realistic attribute levels, conventional gasoline vehicles still dominate both in the US and Japan. However, in an innovation scenario with a significant purchase price reduction, we observe a high penetration of alternative fuel vehicles both in the US and Japan. We illustrate the potential use of a discrete choice analysis for forward-looking policy analysis, with the future opportunity to compare its predictions against actual revealed choices. In this case, increased purchase price subsidies are likely to have a significant impact on the market shares of alternative fuel vehicles.     

城市轨道交通电气系统网络负荷建模方法研究

城市轨道交通电气系统网络存在分散性、时变性、随机性、多样性和非连续性等多种特性。介绍了几种常用的经典负荷模型结构。针对该电气系统网络系统的特点,采用带有反馈模拟云数据生成器,应用隶属度函数与经典负荷模型相结合理论,提出一种基于窗函数的负荷模型建模方法,并对该方法进行了仿真验证。