轨道交通列车再生制动能量回馈装置研究

随着国内电力电子变流技术的成熟,将再生制动电能逆变至更高电压等级的回馈方案已成为轨道交通列车再生制动电能吸收技术的发展方向。介绍了轨道交通列车再生能量吸收技术发展的现状;分析了几种常见的再生制动能量吸收装置的优、缺点;通过仿真分析,定性分析了能量回收效率与行车密度、相邻列车之间的关系。这为再生制动能量回馈装置的合理配置提供参考。     

有源稳压滤波装置在铁路供电系统电能质量问题中的应用

铁路供电系统中往往存在大量的谐波、电压波动和闪变、电压骤降、短时中断、三相不平衡等等严重的电能质量问题,导致用电设备不能够正常工作,这种情况在牵引变电站尤其严重。牵引变电站为了向二次设备提供稳定的低压工作电源,通常使用常规电磁式稳压装置来稳定电压,但是该方法不能消除谐波、对电压波动的响应速度慢,工作范围窄,不能够有效地保护用电设备。采用基于电力电子的有源稳压滤波装置从原理上可克服常规电磁式稳压电源的缺点,有效地解决电能质量问题对用电设备的影响。     

减压阀连续运行试验研究

通过了解减压阀内部结构和基本工作原理,研究影响减压阀运行的主要因素和对管道系统造成的危害,对比减压阀标准的性能技术要求,提出减压阀连续运行试验装置的研制方案,利用该装置对减压阀进行试验,分析试验结果,对减压阀结构工艺提出质量要求。     

基于"按需照明"的隧道照明能效分析研究

隧道照明系统是影响行驶安全和舒适的重要因素,良好的照明环境是隧道运营安全的有力保障.然而隧道照明系统的电能消耗一般占隧道总电能消耗的70％以上,巨大的电费支出往往成为运营单位的重要负担.随着交通量的增加,隧道照明系统须进行亮度的提升,在提升亮度的同时必须考虑照明系统的智能化调控,以做到"按需照明",避免过度照明造成的无效电能消耗.本文针对某隧道的照明系统改造升级方案,通过数值模拟预估了其实施后的亮度水平,基于"按需照明"的理念,提出了降低电能消耗的技术方案和路线.     

鄯兰原油管道超低输量输送方案电耗分析

2008年冬季,鄯兰原油管道计划输量大幅度下调,仅为设计输量的1/4。为避免对泵机组造成损害、提高设备运行效率,提出采用间歇输送方式。根据不同输送方式（连续输送和间歇输送）确定可行的开泵方案,并计算泵机组电能消耗。从开泵数目、泵机组运行时间以及泵效这几方面对不同输送方案的耗电量进行了分析。比选结果表明：采用运行流量1 000 m3/h,单次输送110 h、停输48 h的间歇输送方案所消耗的电能最少,具有显著的经济效益。     

电动汽车动力电池双向充电器无功治理功能研究

双向变流器自身可以做到功率因数为1,还可根据需求输出必要的有功和无功到交流侧,而电网中有大量波动的无功负载和非线性负载,这会导致电网的供电质量下降。文章采用三相桥式PWM双向变流器作为主电路,进行三相桥式双向变流器的数学模型分析,讨论了具备无功治理功能的动力电池充电双向变流器的工作方式,并通过仿真分析了双向变流器在能量吸收模式下进行无功治理、仅能量回馈模式以及能量回馈同时进行无功治理模式的运行结果,实现了能量吸收及能量回馈模式下的无功治理,结果证明该控制方法可行有效。     

北仑矿石码头取制样设施系统环保措施研究

建造于上世纪80年代的北仑矿石码头铁矿石取制样设备,由于受当时技术、材料和工艺的制约,整个系统对节能环保没有太多考虑,造成整个系统运行后电能浪费严重,同时产生大量粉尘和噪声。通过此次技术改进,成功地解决了上述问题。     

基于锂电池储能技术的门座式起重机节能效果分析

门座式起重机在在提升货物过程中,存储了大量的势能,而在下放货物下降或停止时,货物通过机械传动设备驱动起重电机,产生再生制动现象.传统方法采用制动电阻消耗再生电能,造成电能利用效率低下.为利用这部分再生电能,采用锂电池技术能够有效利用再生电能,从而提升门座式起重机的电能利用效率,达到节能的目的.本文在分析门座式起重机电气结构特点的基础上,分析锂电池储能技术原理,并通过实际测试验证了该技术具有明显的节能效果,在传统变频调速节能的基础上进一步提升了节能空间,值得在全国港口推广应用.     

港口航道泥沙工程交通行业重点实验室

<正>团队依托于交通运输部港口航道泥沙工程交通行业重点实验室,主要从事河流动力学及内河航道治理技术、河口动力学及河口航道治理技术、海岸动力学及波浪-结构-地基相互作用、海岸港口航道治理技术等四个方向的基础理论和应用研究。现有水力学及河流动力学、港口海岸及     

电力滤波装置在索道中的应用

介绍普陀山索道应用电力滤波装置的全过程，经过探讨，分析、设计、制造、安装、调试，有效地抑制了高效对电力系统的危害，电网质量明显改善，功率因数显著提高，从而获得更好的经济效益，使索道设备进入良性循环状态。     

Development a new power management strategy for power split hybrid electric vehicles

Reduction of greenhouse gas emission and fuel consumption as one of the main goals of automotive industry leading to the development hybrid vehicles. The objective of this paper is to investigate the energy management system and control strategies effect on fuel consumption, air pollution and performance of hybrid vehicles in various driving cycles. In order to simulate the hybrid vehicle, the combined feedback–feedforward architecture of the power-split hybrid electric vehicle based on Toyota Prius configuration is modeled, together with necessary dynamic features of subsystem or components in ADVISOR. Multi input fuzzy logic controller developed for energy management controller to improve the fuel economy of a power-split hybrid electric vehicle with contrast to conventional Toyota Prius Hybrid rule-based controller. Then, effects of battery’s initial state of charge, driving cycles and road grade investigated on hybrid vehicle performance to evaluate fuel consumption and pollution emissions. The simulation results represent the effectiveness and applicability of the proposed control strategy. Also, results indicate that proposed controller is reduced fuel consumption in real and modal driving cycles about 21% and 6% respectively.     

Emissions from auxiliary power units and ground power units during intraday aircraft turnarounds at European airports

It is widely known that emissions from aircraft engines, Auxiliary Power Units (APU) and ground handling equipment contribute to air pollution at airports. During the aircraft turnaround process, the main source of emissions is the APU. The use of the APU can be significantly reduced if the aircraft stand is equipped to supply external electrical power and pre-conditioned air to the cabin. This paper analyses the actual duration of APU and external power usage during intraday aircraft turnarounds at 125 airports during June 2015. The data is derived from flight data recording units of more than 200 short-haul, narrow-body jet aircraft, conducting some 25,195 aircraft turnarounds and thus provides the most detailed assessment of aircraft power usage available. A common practice is for the APU to be running for a short period on arrival at the stand (arrival-cycle) and then again for a short period prior to departure (departure-cycle). It is identified in this study that departure-cycle emissions are three times greater than arrival-cycle emissions. These emissions could be reduced if more accurate forecasts of departure times are available to flight crew. The provision of external ground power is found to reduce emissions by up to 47.6%. However, the study also highlights that when the source of external power is a diesel-fuelled mobile Ground Power Unit (GPU), there is a net doubling in emissions of hydrocarbons. APU usage is also observed to vary with outside air temperature (OAT) leading to possible increases in emissions of up to 6%.     

华山索道电力补偿的改造

章介绍了对华山索道电力驱动系统的电力补偿电路的改造，提高功率因素，降低能耗和运行成本的经验，可供有关索道企业参考。     

“富强中国”轮使用岸电项目

推广靠港船舶使用岸电技术是交通运输部近期节能减排重点工作任务之一,该项目"利国、利民、利港、利航"。河北远洋运输集团作为推广靠港船舶使用岸电技术的先行者,积极建设绿色航运,与连云港港口集团共同研制了"高压变频数字化船用岸电系统"。2011年9月在所属"富强中国"大型散货轮上安装、调试成功"岸电"设备,并得到中国船级社的认可。     

Market power and its determinants in the Chinese airline industry

This paper first measures the degree of Chinese airlines’ market power by using Lerner index, and then investigates its determinants. Our empirical results show that a certain degree of market power exists in the Chinese airline industry. Of the three dominant carriers, Air China exhibits the strongest market power whereas China Eastern Airlines the weakest, with China Southern Airlines being in the middle. Furthermore, the extent of market power varies significantly among regional markets, with China’s northeast region as the strongest, followed by the eastern and western regions, and the central area as the weakest. We also find a hub-premium effect similar to the result found in the US airline market. Our analysis shows that the existence of high-speed rail and low-cost carriers, income level, population size, seasonality, and number of competing airlines are the main determinants of competition in the Chinese airline market.     

The inverse power transformation logit and dogit mode choice models

This paper explores the properties of inverse Box-Cox and Box-Tukey transformations applied to the exponential functions of logit and dogit mode choice models. It is suggested that inverse power transformations allow for the introduction of modeler ignorance in the models and solve the “thin equal tails” problem of the logit model; it is also shown that they allow for asymmetry of response functions in both logit and dogit models by introducing alternative-specific parameters which make cross elasticities of demand among alternatives generally asymmetric. In the dogit model, modeler ignorance and consumer captivity remain conceptually distinct. Standard logit and dogit models appear as very special “perfect knowledge” cases in broad spectra of models which also include, among others, the reciprocal extreme value or log-Weibull variants. These improvements over the simple symmetric-thin-equal-tail-perfect-knowledge logit and the symmetric-pure-captivity dogit are achieved at the cost of introducing at the most two new parameters per alternative considered in the original logit and dogit mode choice models.     

Hydrogen refueling station networks for heavy-duty vehicles in future power systems

A potential solution to reduce greenhouse gas (GHG) emissions in the transport sector is to use alternatively fueled vehicles (AFV). Heavy-duty vehicles (HDV) emit a large share of GHG emissions in the transport sector and are therefore the subject of growing attention from global regulators. Fuel cell and green hydrogen technologies are a promising option to decarbonize HDVs, as their fast refueling and long vehicle ranges are consistent with current logistic operational requirements. Moreover, the application of green hydrogen in transport could enable more effective integration of renewable energies (RE) across different energy sectors. This paper explores the interplay between HDV Hydrogen Refueling Stations (HRS) that produce hydrogen locally and the power system by combining an infrastructure location planning model and an electricity system optimization model that takes grid expansion options into account. Two scenarios – one sizing refueling stations to support the power system and one sizing them independently of it – are assessed regarding their impacts on the total annual electricity system costs, regional RE integration and the levelized cost of hydrogen (LCOH). The impacts are calculated based on locational marginal pricing for 2050. Depending on the integration scenario, we find average LCOH of between 4.83 euro/kg and 5.36 euro/kg, for which nodal electricity prices are the main determining factor as well as a strong difference in LCOH between north and south Germany. Adding HDV-HRS incurs power transmission expansion as well as higher power supply costs as the total power demand increases. From a system perspective, investing in HDV-HRS in symbiosis with the power system rather than independently promises cost savings of around seven billion euros per annum. We therefore conclude that the co-optimization of multiple energy sectors is important for investment planning and has the potential to exploit synergies.     

A bi-objective maintenance scheduling for power feeding substations in electrified railways

Railway infrastructure is characterized by intensive capital investment, long lifecycle and low return. It is crucial to attain a reasonable system reliability while keeping the recurrent cost manageable throughout the asset lifecycle. Power feeding substations are the key assets on electrified rail lines. As they are subject to various adverse operating conditions, maintenance works of different levels are scheduled to ensure reliability and extend the asset life time if possible. Maintenance scheduling is often regarded as a trade-off between reliability and cost. This study incorporates considerations of different levels of maintenance activities to balance between reliability and cost. In establishing the system reliability model, the contribution of individual component reliability toward the overall system reliability is extracted from the functional relationship among the components. Solution methodologies to this scheduling problem are also proposed here. Evaluation of the scheduling model and the proposed solution is discussed and analyzed through simulation. To cater for the operating conditions in different systems, the impact of weighting factors between reliability and cost on the variations of resulting schedules will be investigated.     

The power of reforming streets to boost access for human-scaled vehicles

This commentary argues for strategies to rapidly increase access by small, human-scaled modes in cities through changes to street designs. Such rapid transformations are necessary as part of responses to critical environmental, economic and public health challenges cities face. We explain that even though coordinated transport and land use planning is desirable, the built environment is mature and slow to change, while streets can and have changed in character and use frequently. This suggests that access to employment, amenities and services should be dramatically increased through reoriented street space toward human-scaled transport modes which will improve safety, reduce pollution, and save households and governments money. We then articulate the prospects of a new generation of accessibility research based on network evolution.     

Evaluation of fuel cell auxiliary power units for heavy-duty diesel trucks

A large number of heavy-duty trucks idle a significant amount. Heavy-duty line-haul truck engines idle about 20–40% of the time the engine is running, depending on season and operation. Drivers idle engines to power climate control devices (e.g., heaters and air conditioners) and sleeper compartment accessories (e.g., refrigerators, microwave ovens, and televisions) and to avoid start-up problems in cold weather. Idling increases air pollution and energy use, as well as wear and tear on engines. Efforts to reduce truck idling in the US have been sporadic, in part because it is widely viewed in the trucking industry that further idling restrictions would unduly compromise driver comfort and truck operations. The auxiliary power units (APUs) available to replace the idling of the diesel traction engine all have had limited trucking industry acceptance. Fuel cells are a promising APU technology. Fuel cell APUs have the potential to greatly reduce emissions and energy use and save money. In this paper, we estimate costs and benefits of fuel cell APUs. We calculate the payback period for fuel cell APUs to be about 2.6–4.5 years. This estimate is uncertain since future fuel cell costs are unknown and cost savings from idling vary greatly across the truck fleet. The payback period is particularly sensitive to diesel fuel consumption at idle. Given the large potential environmental and economic benefits of fuel cell APUs, the first major commercial application of fuel cells may be as truck APUs.