临近空间机电伺服电源轻小型设计的技术途径

根据临近空间飞行器的任务特点,分析了临近空间飞行器对机电伺服系统输出特性的要求,并对机电伺服系统工作原理进行了概括介绍,由此得到了临近空间机电伺服系统的用电特点,最后从机电伺服系统用电指标的匹配方法和电源设计的角度,提出了提高机电伺服系统用电效率、电源轻小型化设计的技术途径。     

风光互补发电系统的优化设计(I) CAD设计方法

给出了一整套利用CAD进行风光互补发电系统优化设计的方法。为了精确确定系统每小时的运行状态,采用了更精确地表征组件特性及评估实际获得的风光资源的数学模型。为了寻找出以最小设备投资成本满足用户用电要求的系统配置,首先在风力发电机容量固定不变的前提下,计算了与该容量风力发电机匹配的不同容量的PV方阵和蓄电池所组成的风/光/蓄组合的全年功率供给亏欠率LPSP,根据总的设备投资成本最小化的原则筛选出一组与该容量风力发电机对应的满足用户给定系统供电可靠性即LPSP值的风/光/蓄组合;然后通过改变风力发电机的容量,优选出多个与不同容量风力发电机对应的既能满足用户用电要求同时总的设备购置成本又是最低的风/光/蓄组合,比较它们的成本最终唯一确定出以最小投资成本满足用户用电要求的优化的系统配置。     

风光互补发电系统的优化设计(Ⅰ)CAD设计方法

给出了一整套利用CAD进行风光互补发电系统优化设计的方法.为了精确确定系统每小时的运行状态,采用了更精确地表征组件特性及评估实际获得的风光资源的数学模型.为了寻找出以最小设备投资成本满足用户用电要求的系统配置,首先在风力发电机容量固定不变的前提下,计算了与该容量风力发电机匹配的不同容量的PV方阵和蓄电池所组成的风/光/蓄组合的全年功率供给亏欠率LPSP,根据总的设备投资成本最小化的原则筛选出一组与该容量风力发电机对应的满足用户给定系统供电可靠性即LPSP值的风/光/蓄组合;然后通过改变风力发电机的容量,优选出多个与不同容量风力发电机对应的既能满足用户用电要求同时总的设备购置成本又是最低的风/光/蓄组合,比较它们的成本最终唯一确定出以最小投资成本满足用户用电要求的优化的系统配置.     

风光互补发电系统的优化设计（I）CAD设计方法

给出了一整套利用CAD进行风光互补发电系统优化设计的方法。为了精确确定系统每小时的运行状态,采用了更精确地表征组件特性及评估实际获得的风光资源的数学模型。为了寻找出以最小设备投资成本满足用户用电要求的系统配置,首先在风力发电机容量固定不变的前提下,计算了与该容量风力发电机匹配的不同容量的PV方阵和蓄电池所组成的风／光／蓄组合的全年功率供给亏欠率LPSP,根据总的设备投资成本最小化的原则筛选出一组与该容量风力发电机对应的满足用户给定系统供电可靠性即LPSP值的风／光／蓄组合;然后通过改变风力发电机的容量,优选出多个与不同容量风力发电机对应的既能满足用户用电要求同时总的设备购置成本又是最低的风／光／蓄组合,比较它们的成本最终唯一确定出以最小投资成本满足用户用电要求的优化的系统配置。     

风能发电供热互补利用的研究与分析

结合乌兰察布市科布尔镇和赤峰市林东镇两地的风能资源、风电并网状况以及城镇的供热负荷特点,从风电出力特点、电网用电负荷特点以及供热需求等3个方面分析,得出风电与供热负荷在供热期也是用电负荷低估期具有较好的匹配特性;同时,结合两镇的实际特点,根据匹配特性,对两镇的风电供热发电互补利用进行了匹配设计,得出风电供热供电的可行性结论,为大力开发新能源(风能)的推广应用起到了一定的指导作用。     

风电提水系统及参数匹配

分析了小型风电提水系统的主要构成及原理,研究了风力发电机与潜水电泵参数的优化匹配问题,提出了用单片机通过逆变器进行控制的方法.以1 000 W风力发电机和550 W水泵为例进行了试验,其结果基本能满足风力机和水泵的匹配要求.     

城市公交车发动机循环工况的试验研究与建立

通过公交车市区道路试验,在获取大量反映公交车市区行驶特性数据的基础上,利用多元统计理论确定了城市公交车行驶工况的解析方法,建立了能够反映城市公交车实际行驶特征的城市公交车行驶循环工况,并对建立的公交车行驶循环工况的有效性进行了试验和理论验证.通过建立试验公交车的整车性能仿真模型,将公交车运行驶工况转化为发动机循环工况.研究表明：GB/T12545.2-2001中规定的用于评价公交车燃油经济性的四工况与循环建立的公交车行驶工况具有较大差别.     

新供给模式下城市建筑屋顶光伏发电的利用潜力分析

为了提高城市建筑屋顶光伏发电系统的利用价值和经济效益,从不同的用户侧角度分析,利用k均值聚类的方法得到了不同类型城市建筑的用电特征,并与软件模拟得到的典型屋顶光伏发电系统的发电特征结合进行了匹配分析,提出了"在居住建筑的屋顶安装光伏发电系统,为周围办公建筑供电"的模式.以上海市10个区域为例,结合模拟退火算法,计算得到...     

小型风力发电机的功率控制方法

将风力发电机叶片的功率一转速特性曲线划分为峰前、峰值和峰后3个区域.根据在各种风速下风力发电机叶片与电机的功率匹配特性,提出一种小型风力发电机的功率控制新方法;通过300 W/24 V风力发电机的设计和测试,验证了此功率控制方法的正确性和可行性.     

离网型风力发电机的大风限速保护研究

如果解决不好离网型风力发电机的大风限速保护问题,就会大大地降低其可靠性和安全性.文章从风轮与发电机的匹配人手,一改传统离网型风力发电机最佳功率匹配运行为峰前匹配运行,使风力发电机在大风时保持较低的风能利用系数,具有大风时的限速保护作用.     

Environmental life cycle assessment of alternative fuels for city buses: A case study in Oujda city,Morocco

The road transport sector, particularly public transport, generates significant greenhouse gas emissions due to the excessive use of petroleum-based fuels. The use of alternative fuels with lower environmental impacts is therefore a major challenge to move towards a more sustainable public transport sector. In this context, the current study presents an environmental life cycle assessment of alternative buses, including hybrid (diesel-electricity), electric, and fuel cell buses at a city level in Oujda, Morocco. This study is perfromed according to three main outputs: total energy use by fuel type, GHG emissions, and criteria air pollutants. It is concluded that electric and fuel cell buses represent efficient and sustainable alternatives to public transport during the operational phase and their deployment in Oujda city can potentially offer significant environmental savings in terms of GHG emissions and air pollutants during both the WTT and TTW phases.     

公交车辆制动能量回收与再利用系统研究

能源与环保现已成为社会发展的主题，作为能源消耗大户—公交车辆，其节能性能越来越受到人们的关注与研究。介绍了各种公交车辆制动能量回收与再利用方式的研究现状，分析了各种方式的局限性，并针对性的对液压储能方式在车辆能量回收与再利用系统中的特点和应用给予了详细的论述，然后针对具有特殊运行工况的城市公交车辆，提出了一种制动能量回收与再利用系统的模型，以期改善车辆的燃油与环保性能。     

Life cycle assessment of alternative energy types – including hydrogen – for public city buses in Taiwan

Human activities have exacerbated the global greenhouse effect, resulting in extreme climate changes that have caused disasters and food and water shortages in recent years. Transportation is one of the main causes of global greenhouse gas (GHG) emission. Therefore, policy makers must develop feasible strategies to reduce GHG emission. One of Taiwan's policy is to replace traditional diesel fuel urban buses with alternative energy buses. This paper uses a case study of city bus route No. 2 in Tainan City following the international standard ISO/TS 14067:2013 to measure the carbon footprint of different energy buses. The bus carbon footprints measured from high to low as: LNG buses, 63.14 g CO2e/pkm; traditional diesel buses, 54.6 g CO2e/pkm; liquefied petroleum gas (LPG) buses, 47.4 g CO2e/pkm; plug-in electric buses, 37.82 g CO2e/pkm, and hydrogen fuel cell buses, 29.17 g CO2e/pkm. If all urban area public buses in Taiwan were switched to hydrogen fuel cell buses, this would reduce CO2e footprint by 227,832.39 t annually. This reduction is equivalent to planting 22.78 million trees.     

Bluetooth wireless monitoring,diagnosis and calibration interface for control system of fuel cell bus in Olympic demonstration

With the worldwide deterioration of the natural environment and the fossil fuel crisis, the possible commercialization of fuel cell vehicles has become a hot topic. In July 2008, Beijing started a clean public transportation plan for the 29th Olympic games. Three fuel cell city buses and 497 other low-emission vehicles are now serving the Olympic core area and Beijing urban areas. The fuel cell buses will operate along a fixed bus line for 1 year as a public demonstration of green energy vehicles. Due to the specialized nature of fuel cell engines and electrified power-train systems, measurement, monitoring and calibration devices are indispensable. Based on the latest Bluetooth wireless technology, a novel Bluetooth universal data interface was developed for the control system of the fuel cell city bus. On this platform, a series of wireless portable control auxiliary systems have been implemented, including wireless calibration, a monitoring system and an in-system programming platform, all of which are ensuring normal operation of the fuel cell buses used in the demonstration.     

Life Cycle Assessment (LCA) for use on renewable sourced hydrogen fuel cell buses vs diesel engines buses in the city of Rosario,Argentina

The purpose of this paper is to build the first Energy and Life Cycle Analysis (LCA) comparison between buses with internal combustion engine currently used in the city of Rosario, Province of Santa Fe, Argentina, and some technological alternatives and their variants focusing on buses with an electrical engine powered by compressed hydrogen that feet fuel cells of polymer electrolyte membrane (PEM). This LCA comprehend raw material extraction up to its consumption as fuel. Specifically, hydrogen production considering different production processes from renewable sources called “green hydrogen” (Velazquez Abad and Dodds, 2020) [1] and non-renewable sources called “grey hydrogen” (Velazquez Abad and Dodds, 2020) [1]. Renewable sources for hydrogen production are rapid cut densified poplar energy plantation, post-industrial wood residues such as chips pallets, and maize silage. For non-renewable hydrogen production sources are the local electrical power grid from water electrolysis and natural gas from the steam methane reforming process.Buses whose fuel would be renewable hydrogen, produced near the City of Rosario, Province of Santa Fe, Argentina, meet one of the main criteria of sustainability biofuels of the European Union (EU) taken into account Renewable Energy Directive (RED) 2009/28 [2] and EU RED Directive 2018/2001 [3] that need significant reduction on net greenhouse gases (GHG) from biomass origin row material respect fossil fuels. At least 70% of GHG would be avoided from its main fossil counterpart of the intern combustion engine (ICE), in the worst and current scenario of the emission factor of the electrical grid of Argentina in the point of use that is about 0.40 kg CO_2eq/kWh with energy and environmental load of 100% in the allocation factor in the hydrogen production stage of the LCA analysis.     

琅驰6C系列客车专用柴油机性能开发

针对客车专用柴油机的配试要求,对琅驰6C系列发动机的增压系统、燃油喷射系统、燃烧系统等进行优化改进。根据综合性能配试结果,确定了对琅驰系列柴油机采用的综合性技术措施,并对改进后的发动机进行了综合试验与分析。发动机经综合优化后,在保持原有性能水平的基础上,琅驰6C系列客车发动机还具有低排放、较低的工作运行油耗、起动和换档加速性能好等特点。琅驰6C系列客车发动机的开发成功,为城际干线配套动力、农村道路标准化配套动力、城市公交配套动力提供了从158～206kW功率范围的配套解决方案。     

Performance analysis of proton-exchange membrane fuel cell stacks used in Beijing urban-route buses trial project

Fuel cell hybrid vehicles' sustained development and commercialization are contingent on the reliability and durability of the fuel cell engines. In August 2008, official trial of the three proton-exchange membrane (PEM) fuel cell hybrid city buses commenced in a commercial-operation urban-route in Beijing for one year. In this paper, data from the performance analysis of the automotive fuel cells used in those city buses are presented and analyzed. The durability and reliability of the fuel cell engines under realistic conditions were evaluated by analyzing the standard deviation of the single-cell fuel cell voltages and by estimating the voltage vs. current characteristics obtained using the recursive least squares fitting method. After studying the degradation status by analyzing fitted results from the measured data, it is concluded that the fuel cell engines' performance meets the standard imposed by the driving conditions of the Beijing urban-routes, but that their performance degradation necessitates maintenance in order to ensure normal operation.     

Alternative fuel buses currently in use in China: Life-cycle fossil energy use,GHG emissions and policy recommendations

The Chinese government has enacted policies to promote alternative vehicle fuels (AVFs) and alternative fuel vehicles (AFVs), including city bus fleets. The life cycle (LC), energy savings (ES) and GHG reduction (GR) profiles of AVFs/AFVs are critical to those policy decisions. The well-to-wheels module of the Tsinghua-CA3EM model is employed to investigate actual performance data. Compared with conventional buses, AFVs offer differences in performance in terms of both ES and GR. Only half of the AFVs analyzed demonstrate dual benefits. However, all non-oil/gas pathways can substitute oil/gas with coal. Current policies seek to promote technology improvements and market creation initiatives within the guiding framework of national-level diversification and district-level uniformity. Combined with their actual LC behavior and in keeping with near- and long-term strategies, integrated policies should seek to (1) apply hybrid electric technology to diesel buses; (2) encourage NG/LPG buses in gas-abundant cities; (3) promote commercialize electric buses or plug-in capable vehicles through battery technology innovation; (4) support fuel cell buses and hydrogen technology R&D for future potential applications; and (5) conduct further research on boosting vehicle fuel efficiency, applying low-carbon transportation technologies, and addressing all resultant implications of coal-based transportation solutions to human health and natural resources.     

天然气大客车发动机与传动系的匹配分析

介绍了在开发低排放天然气大客车中,利用自行开发的汽车性能模拟计算软件,对选择的3 种天然气发动机与传动系统的匹配作了分析,并进行了动力性能的模拟计算,使开发的新型大客车的性能最佳,为天然气大客车的设计开发提供指导。