基于紫外成像的电晕放电检测技术改进研究

针对当前电晕放电检测存在检测精度低的问题,提出一种基于紫外成像的电晕放电检测方法。该方法将基于紫外成像的电晕放电检测效果的干扰因素划分为距离、增益、温度和湿度检测等;构建了紫外线成像电晕放电检测体系,采用物镜系统解决电晕放电目标成像问题,利用光传感器将电晕放电图像进行光电转换,结合紫外滤光片滤除日盲区之外的光波,采用控制分析体系将光的强度量进行统计并分析,同时控制整个检测体系。利用图像显示体系将电晕放电图像信息融合、显示。在紫外线成像电晕放电检测体系基础上,分别对检测干扰因素逐一处理,设计基于紫外成像的电晕放电检测流程图,完成电晕放电高质量检测。实验表明,文章所提方法不仅有效处理了电晕放电检测干扰因素,还提高了放电源检测的检测精度。     

基于声发射波关联维数的避雷器异常放电识别

避雷器异常放电的现有识别方法难以判断异常放电时的吸收声波特性,导致识别结果不准确,以110 kV交流避雷器为研究对象,对避雷器异常放电类型进行识别。采用声发射技术来检测110 kV交流避雷器雷电异常放电特性,获取雷电影响下110 kV交流避雷器放电时的吸收声波;基于获取的放电吸收声波,采用关联维数的避雷器雷电异常放电吸收波特征分析方法,实现110 kV交流避雷器雷电异常放电吸收声波的特性分析。实验结果表明：该方法通过关联维数判断避雷器放电吸收声波的特性,能够有效判断雷电影响下110 kV交流避雷器每种异常放电的情况,且通过该方法识别110 kV交流避雷器雷电异常放电类型时,识别结果全部通过,因此该分析方法的应用价值显著。     

三电极等离子点火器激励参数的优化选择

为了扩大点火火核体积,提高放电等离子体点火器的点火可靠性,本文采用了三电极结构来产生大体积的稳定放电。试验对比了不同激励电压、电流下的放电特性,获取了最大放电通道体积时的外激励参数。结果表明:激励电流对放电通道体积的促进作用较弱,随着激励电流的增加,放电通道体积基本无变化,放电通道的功率密度持续上升。激励电压对放电通道体积的促进作用较大,随着激励电压的增加,放电通道体积先增大后不变,放电通道的功率密度则会先降低后上升。对比之下,增大激励电压可以获取更大的放电通道体积。     

短间隙下不同避雷针接闪性能试验研究

为探究不同避雷针在短间隙下的接闪特性,采用-250/2 500μs冲击电压波分别对全尺寸和缩小比例的可控放电避雷针、传统避雷针、普通避雷针进行间隙距离分别为0.3、0.6、0.9、1.2m的放电特性试验,采用升降法获取了不同避雷针的间隙放电电压参数和光学影像。结果表明,间隙距离为1.2m时,避雷针的50%放电电压的大小关系为普通避雷针传统避雷针可控放电避雷针,即在相同试验条件下可控放电避雷针更易于发生接闪。此外,为更加直观地比较不同避雷针在放电能力上的差异性,设计了双避雷针选择性放电试验,每组试验放电40次,发现可控放电避雷针的接闪概率分别为传统避雷针、普通避雷针的1.86、4.00倍。     

高压开关柜局部放电检测及定位方法研究

局部放电检测是开关柜状态检修的重要手段,局部放电检测方法多样,每种检测方法各有优缺点,检修人员在工作中难以判断何种检测手段更加适合现场需求。通过对开关柜放电损坏过程进行分析,论证了局部放电检测的必要性;通过对开关柜局部放电时产生的变化进行分析,论证了局部放电检测的可行性;通过实例对常见的暂态地电压、特高频、超声波等局部放电检测方法及定位方法的开展过程及优缺点进行分析,为局部放电检测方法的选取提供了参考。     

基于静态贝叶斯博弈的电动汽车放电电价分析

车电互联是未来对电网负荷削峰填谷的重要途径之一。合理制定电动汽车放电电价是车电互联实施的关键。作为车电互联的博弈双方,电动汽车用户和电网公司采用静态贝叶斯博弈,引入双方报价拍卖模型来制定放电电价。文章以上海市为例,计算了电动汽车在不同放电量下的放电电价取值以及双方的相应收益。研究结果表明,放电电价与放电量呈正相关,随着放电量的增加,车电互联双方的单位电能收益也会随之增加。     

雷电冲击电压下油纸绝缘气隙局部放电特性

针对变压器在雷电冲击试验中出现局部放电却无法有效诊断分析的现状,构建油纸绝缘多尺度气隙缺陷模型,探究冲击电压条件下局部放电特征。基于油纸绝缘气隙缺陷在雷电冲击电压下的放电特点,将雷电冲击电压作用时间划分为波前时间、半峰值时间、延迟时间和去电荷时间四个阶段,详细阐述了去电荷阶段局部放电驱动机制。结果表明,半峰值时间和去电荷时间内局部放电脉冲极性相反,且在去电荷阶段内脉冲放电无过冲振荡现象,随着气隙高度的增大,延时放电时间延长,平均放电量增加,累积放电量减小,且放电重复率减小。     

GIS金属颗粒放电发展的试验研究

为了观察GIS内部绝缘子表面固定金属颗粒放电的发展过程,在252 kV GIS中设置绝缘子表面固定金属颗粒缺陷,采用长时间逐步升压法使放电起始、发展直至沿面闪络.在放电发展过程中采用脉冲电流法实时监测局部放电的脉冲,统计形成表面固定金属颗粒局部放电发展过程中不同阶段的N-φ谱图、Vmax-φ谱图以及Vave-φ谱图.实验结果表明:随着放电的发展,局部放电的谱图出现变化,产生一些相应的特征:在放电发展中期,N-φ谱图的负半波会呈现双峰结构,在相位250°附近会出现幅值较大、次数较多的放电,并在338°～353°相位区间内将出现放电,这些都是有别于局部放电初期阶段的重要特征.     

高频电流脉冲法在抽水蓄能电站主变压器局部放电检测的应用

为应对常规高频电流脉冲法在测量局部放电时存在干扰信号,而导致影响局部放电判断的问题,本文通过模糊分类理论,取得了区分高频信号中局部放电信号和干扰信号的良好效果。结合局部放电产生机理,分析了不同类型局部放电信号在相位幅值（PRPD）谱图上的分布特征,并应用于脉冲信号的局部放电判断。测量了某抽水蓄能电站多台主变压器在不同工况下接地系统的高频电流脉冲,展示了环境噪声信号、具有固定相位特征的非放电信号等多种信号的PRPD谱图脉冲分布,判断了某台主变压器可能存在外部沿面局部放电情况。     

基于紫外成像法的绝缘子电晕放电影响因素试验研究

绝缘子局部电晕放电的紫外检测是判定在线运行绝缘子绝缘性能的重要手段之一。采用光子型紫外探测器检测降雨量、污秽、均压环布置方式等不同试验条件下绝缘子的局部电晕放电程度,统计了检测到的光子数均值,进而分析不同因素对绝缘子电晕放电的影响。结果表明,污秽加剧了绝缘子的局部电晕放电程度;降雨量与绝缘子局部电晕放电程度具有复杂关系;绝缘子局部电晕放电程度与外施电压幅值呈指数增长关系;高压端均压环对绝缘子串的局部电晕放电具有关键作用。     

藏北高原典型草甸下垫面与HEIFE沙漠区辐射平衡气候学特征对比分析

利用中日合作“全球能量与水分平衡试验一青藏高原季风试验(GAME—Tibet)”和中日合作“黑河地区地一气相互作用野外观测实验研究(HEIFE)”IOP、FOP资料,计算分析了藏北高原典型草甸下垫面安多站和HEIFE沙漠站的辐射平衡各相关特征量时频变化的气候学特征。结果表明：无论是高原安多站还是黑河沙漠站,夏季均出现超太阳常数现象(只是安多更为明显);总辐射、大气逆辐射、地表长波辐射、地表有效辐射和地表辐射平衡等的日变化(晴天)无论是安多站还是沙漠站均表现为早晚出现最小值而正午附近(地方时)达到最大值,而地表反照率的日变化(晴天)相反表现为早晚大而正午附近小的规律;上述各分量均表现有程度不等的季节变化规律：总辐射、大气逆辐射、地表长波辐射和地表辐射平衡均表现为夏半年增大达到最大值百而冬半年降低量出现最小值;另外,大气长波辐射、地表有效辐射和地表反照率在沙漠站的年际变化的振幅较安多站更为显著和有规律。     

柴油机磨合规范优化及其油液分析

本文根据４９５Ａ柴油机的特点,结合摩擦学磨合机理,给出了４９５柴油机最佳磨合的优化指标。借助油液分析的光谱、铁谱技术可以定量地判断分析磨合过程及其趋势。为了合理地缩短柴油机磨合时间,同时又提高柴油机的整机磨合质量,研制了新配方的专用柴油机磨合油。Ｌ７ 磨合油允许空载磨合初期提高磨合速度,实现高磨损率,但产生的磨粒细微,不会擦伤磨合表面。试验表明,执行新磨合规范可以缩短磨合时间４１．７％ 。     

What goes down must come up? Trends of industrial electricity use in the North-West of Russia

This article uses decomposition method to analyse industrial electricity consumption in North-Western Russia, namely in Archangelsk oblast, the Republic of Karelia and Murmansk oblast. The case sectors, forestry and electricity, have in most cases developed similarly in the chosen regions during 1990–2001. The decomposition analysis shows that the reduction of economic activity has reduced electricity consumption in all three regions but that it is not always the main factor reducing consumption. The changes in energy efficiency increased consumption in the forestry sector in all regions while in the electricity sector it led to a reduction. The changes in the structures of the regional economies increased electricity consumption in electricity industry which gained importance due to developments in the manufacturing industry. In Murmansk, forestry sector has almost disappeared during the observation period. This was the main observed electricity consumption reduction caused by structural changes. Many of the developments can be better understood against the general knowledge of transition factors.     

Exploration of the land potential for the production of biomass for energy in the Netherlands

The energy potential for energy crops and biomass residues in the Netherlands is assessed. The analysis explores the possible use of land for biomass production in the future. Various government memorandums and analyses of the expected future land use in various sectors have served as the basis for the assessment of the supply of and the demand for land in the future. In this study the potential supply of agricultural land is based on expected productivity increments in agriculture and assumptions with respect to the future demand for agricultural products. Various future claims for infrastructure, forestry, urban areas and nature are subtracted from the expected supply. The net projected supply of land ranges from zero to 52 000 ha in 2000 to 110 000-250 000 ha in 2015. The supply of agricultural land depends however on a number of supra-national factors, such as the European agricultural policy, world market developments and the agricultural production in the countries in Eastern Europe. Uncertainties remain, therefore, and the projected supply of agricultural land should be considered as a possible scenario based on current trends. If the calculated land potential is used for energy crops like miscanthus and short rotation coppice, this land could contribute 0-10 PJ in 2000 and 27-59 PJ in 2015. Secondary biomass yields, such as those from forestry, agricultural residues, wood from prunings, etc., could contribute a further 34 PJ in 2000, decreasing to approximately 28 PJ in 2015. Taken together these potentials could satisfy 1-1.5% of the energy requirements of the Netherlands in 2000 and 1.5-2.5% in 2015, provided that energy farming is an economically feasible activity for farmers.     

王官屯油田官142地区中生界地层特征

王官屯油田地处河北省沧县王官屯乡境内,区域构造位置为黄骅坳陷南区孔店构造带的西南端,处于孔东断裂带两侧。根据钻录井特征、地球物理响应特征,结合区域地层对比,将王官屯油田官142地区中生界地层划分为中下三叠统、中下侏罗统、上侏罗统-下白垩统三套旋回。通过对该区地层特征的分析,认为中下三叠统以棕红、紫红色粉细砂岩和泥岩互层为主;中下侏罗统下部主要为暗色泥岩夹砂岩,上部为一套巨厚砂砾岩,并作为中生界油藏主要储集层;上侏罗统-下白垩统发育紫红色砂岩及安山岩。通过分析各时期的构造运动特征,认为印支运动以整体抬升为主,发育了三叠系地层;燕山早期以走滑和挤压为主,盆地规模较小,发育中下侏罗统的河湖相沉积;燕山中期火山活动强烈,发育火山物质为主的晚侏罗世-早白垩世地层;燕山晚期该区整体抬升遭受剥蚀,缺失上白垩统地层。而喜山时期的升降运动对中生界油气成藏具有重要意义。     

Why did the energy intensity fall in China's industrial sector in the 1990s? The relative importance of structural change and intensity change

There have been a variety of studies investigating the relative importance of structural change and real intensity change to the change in China's energy consumption in the 1980s. However, no detailed analysis to date has been done to examine whether or not the increased energy efficiency trend in the 1980s still prevailed in the 1990s. This article has filled this gap by investigating the change in energy consumption in China's industrial sector in the 1990s, based on the data sets of value added and end-use energy consumption for the 29 industrial subsectors and using the newly proposed decomposition method of giving no residual. Our results clearly show that the overwhelming contributor to the decline in industrial energy use in the 1990s was the decline in real energy intensity, indicating that the trend of real energy intensity declines in the 1980s at the 2-digit level was still maintained in the 1990s. This conclusion still holds even if we lower the growth rate dramatically in line with the belief that the growth rate of China's GDP may be overestimated.     

The impact of the European Union emission trading scheme on the electricity-generation sector

In order to comply with their commitments under the Kyoto Protocol, France and Germany participate in the European Union Emission Trading Scheme (EU ETS) which predominantly concerns the electricity-generation sectors. In this paper we ask whether the EU ETS provides the appropriate economic incentives to produce an efficient system in line with the Kyoto commitments. If so, electricity producers in the countries concerned should include the price of carbon in their cost functions. After identifying different sub-periods of the EU ETS during its pilot phase (2005–2007), we model the prices of various electricity contracts in France and Germany and look at the volatility of electricity prices around their fundamentals while evaluating the correlation between electricity prices in the two countries. We find that electricity producers in both countries were constrained to include the carbon price in their cost functions during the first two years of the EU ETS. Over this period, German electricity producers were more constrained than their French counterparts, and the inclusion of the carbon price in the electricity-generation cost function was much more stable in Germany than in France. We also find evidence of fuel switching in electricity generation in Germany after the collapse of the carbon market. Furthermore, the European market for emission allowances has greatly contributed to the partial alignment of the wholesale price of electricity in France to that in Germany.     

基于相对湿润度指数的贵州省近十年干旱特征分析

为分析贵州省干旱分布特征,基于贵州省均匀分布的30个气象站点2010～2019年的逐日气象数据,以相对湿润度指数为干旱监测指标,利用反距离权重插值分析及相关分析研究贵州省近10年的干旱特征.结果 表明,贵州省不同月份的干旱强度和干旱发生范围有所不同,且总体上呈干旱等级越高,干旱范围越小的态势.不同时间尺度的干旱强度和干...     

Hydrogen in China: Policy,program and progress

The paper introduces the role of energy in China economy context, criteria for sustainable development in energy sector, China's hydrogen vision, the role of hydrogen in China's R&D plan, recently launched national programs, and progresses and achievements in research, development and demonstration. The paper concludes that with fast economy development in the new era in China, the energy sector has been confronted with severe challenges in terms of supply security, environment pollution and greenhouse gas emission, and China has attached significant priority on research and development in hydrogen and fuel cell areas, as one of effective counter-measures to address these challenges. Transition to the hydrogen economy in China, a long-term, non-carbon energy solution, is believed to play a significant role, complementary to electricity, in the future sustainable energy system. It is recommended that more priority be attached for R&D in secondary industry, especially the utilization of hydrogen and fuel cell in stationary power generation from coal gasification.