110 kV并联可控电抗器及其应用

介绍了高压可控电抗器在电力系统中的重要作用及其在国内的研究现状，开发了110 kV/30 Mvar裂心式高压并联可控电抗器工业样机及相应的控制装置和保护装置，介绍了其结构形式并分析了工作原理和工作特性。介绍了该可控电抗器在现场的试验过程，并测试了其特性参数。该可控电抗器已在湖南怀化电业局田家220 kV变电站投入运行，使110 kV母线电压稳定在115 kV。     

选择线路并联电抗器应注意的问题

地方电网孤立运行的水电站,系统装机容量小,在长距离小负荷110kV高压供电时,由于线路电容效应,末端电压升高。实践证明采用线路并联电抗器是最好办法,有利于提高输电能力及系统运行的稳定性,运行方便灵活。现就农一师西大桥水电站至农三师小海子图木休克110kV输变电工程(简称西图输变电工程)安装两台10kV线路并联电抗器运行一年来所遇到的实际问题。     

500 kV输电线路断路器合闸电阻配置原则

通过对某500 kV输电线路断路器取消合闸电阻的投切试验、断路器事故进行分析，并对此进行电磁暂态仿真计算，讨论了500 kV输电线路断路器取消合闸电阻的原则，与线路操作过电压幅值、线路两端高压并联电抗器配置情况的关系。研究结果表明，500 kV输电线路断路器合闸电阻配置时，需要考虑线路高压并联电抗器的配置情况，这将直接影响断路器断开的成功与否。     

我国已全面掌握750kV运行技术

9月27日，西北电网有限公司隆重举行750kV输变电示范工程安全运行一周年总结表彰大会，总结我国第一个750kV输变电工程的建设运行经验，表彰作出突出贡献的先进集体和个人，以此推动西北750kV电网和国家特高压电网建设。     

广东(惠汕)500 kV线路国产微机保护配置方案

针对500 kV输电线路保护装置的选型问题，简述了广东电网500 kV线路保护的使用情况 ，分析了国外高压保护产品在国内电网运行中存在的缺陷和问题，叙述了国产保护原理的先 进性、适应性以及国产化、微机化500 kV线路成套保护配置方案。     

浅谈戈壁滩电网施工特点

"西电东送"是优化能源配置的重要战略,电力大动脉电网西电东送沿线为戈壁滩。文章以新疆-西北联网750kV哈密～安西输电线路工程为施工背景,分析西北戈壁滩施工因素,简要阐述了西北戈壁滩的气候、环境、组织、技术等方面特点。     

330kV高压电抗器匝间保护误动原因分析

安装了分相式高压并联电抗器的高压输电线路,在线路发生单相接地故障而断路器单相跳闸瞬间,输电线路和高压电抗器处于缺相运行状态。如果高压电抗器匝间保护的电压采样取自母线TV二次侧,匝间保护在一次设备非全相运行时将会误判成区内故障而动作跳闸。文章根据一起330 kV线路单相瞬时性故障引起电抗器保护装置的匝间保护误动作、造成线路两侧断路器三相跳闸事件,分析了高压电抗器处于各种非正常情况下匝间保护动作原因,指出为防止电抗器非全相运行时匝间保护误动作应采取的措施。     

中国第一个同塔双回750kV输变电工程竣工投产

中国第一个同塔双回750kV输变电工程——750kV兰州东至平凉至乾县输变电工程于2009年5月25日18时正式竣工投产。兰平乾工程于2007年8月15日开工建设,是西北750kV电网主网架的核心工程,是西北实施“西电东送”战略的主通道,对加强陕甘断面潮流交换、确保陕西迎峰度夏期间可靠用电、保持西北电网系统稳定起着重要作用。该电网的建成投产,标志着西北750kV送端电网已覆盖陕西、甘肃、青海、宁夏4省（区）,为实现西北水、火、风电“打捆”外送奠定了坚实的电网基础。     

拉西瓦水电站首批机组顺利并网发电

从黄河流域最大的水电站——拉西瓦水电站传来喜讯，拉西瓦水电站首批2台700MW水轮发电机组并网发电。强大的电能通过拉西瓦-官厅、拉西瓦-西宁2条750kV输电线路输送到西北电网。     

南水北调中线35kV超长输电线路节能与安全改造

针对35k V超长输电线路存在问题,采用集中补偿和分散补偿、SVG动态双向连续补偿和并联电抗器单向分级补偿、35k V电网高压补偿和各负荷站点低压补偿等综合措施,实现35k V输配电系统分(电压)层和分(供电)区的无功平衡,系统功率因数由0.1提高到0.95,节能效果显著;采用增设线路调压器并优化其容量配置,解决了电网电压过高、威胁设备安全运行的问题。     

Call for Papers

正As the eldest and most distributed professional journal of water industry,Water Wastewater Engineering(W WE)gained very wide acceptance from the colleagues working in this field in this country since start publication in 1964.Now it is administrated by the Ministry of Construction of the People’s Republic of China and sponsored by the China Civil Engineering Society etc.     

地下厂房施工过程的三维非线性数值模拟分析

根据冗各电站地下厂房开挖支护的施工顺序,以隐式杆单元模拟锚杆,以壳单元模拟混凝土喷层,采用三维非线性有限元技术,对洞室群的开挖支护动态过程进行了模拟计算。通过三维非线性有限元计算分析得到:洞室群动态开挖过程中围岩应力变形的分布规律,围岩塑性区的发展规律,锚杆受力变化情况。计算结果表明:整个开挖过程中,洞周围岩位移变化规律正常,量值较小,塑性区主要分布在洞室周边,围岩稳定性较好;但在洞室交叉口处围岩的变形较大,出现较大范围的塑性区,在此基础上提出了支护措施优化方案,并对优化方案的效果进行了评价。     

Serial discontinuities in a Rocky mountain river. I. Distribution and abundance of plecoptera

Samples were taken year-round at eleven sites along the altitudinal profile (2900-1400 m a.s.l.) of the Gunnison River, a 329 km tributary of the Colorado River, to document the distribution of the Plecoptera and to evaluate responses to hypolimnial-release dams in the headwaters and middle reaches. Twenty-two species were present, with the greatest species richness occurring in an unregulated segment upstream of the middle reach dams; average nymphal biomass over the study period (175 organisms, 395 mg dry mass m^?2) was also greatest in this segment. Only four species (58 organisms, 48 mg m^?2) were present in the tailwaters of the headwater dam and values were greatly reduced (nine species; 35 organisms, 180 mg m^?2) below the middle reach dams. The stonefly community recovered ca. 80 km downstream from the last dam (15 species; 244 organisms, 250 mg m^?2), apparently in response to natural resetting of environmental conditions corresponding to those above the middle reach dams. At the most downstream site (11) only four species (four organisms, 16 mg m^?2) were present. The observed distributional pattern is a classic serial discontinuity in response to hypolimnial stream regulation in a temperate latitude river.     

Impacts of Microcystis on algal biodiversity and use of new technology to remove Microcystis and dissolved nutrients

Cyanobacteria often dominate eutrophic lakes, outcompeting green algae that are required by fish and zooplankton. This study was undertaken to ascertain the impact of the cyanobacterium, Microcystis, on algal biodiversity. Under laboratory conditions, we found that the presence of Microcystis decreased phyla richness by 58%, phyla evenness by 47%, genera richness by 66% and genera evenness by 51%. Analysis by mixed anova s demonstrated a significant interaction between treatment and time and confirmed a significant reduction in richness and evenness of phyla and genera. We also conducted a phosphate restriction assay on the algae in Mason Lake (Irvine, CA, USA) and found that the threshold needed for algal growth there was 0.02 mg L^?1 PO₄. A pilot study was then conducted to test the effectiveness of the Blue Pro? water treatment facility in removal of this colonial organism from Mason Lake, in addition to removal of dissolved nutrients required for its growth. We measured a 97% reduction in Microcystis cells, a 72% reduction in chlorophyll‐a, and a 96% reduction in phosphate after just one 10 min cycle through the unit. Our study demonstrated that removal of Microcystis colonies may allow green algae to increase in numbers. This may improve algal biodiversity, which will benefit zooplankton and fishes.     

Evaluation of freshwater mussel relocation as a conservation and management strategy

The relocation of unionacean mussels is commonly used as a conservation and management tool in large rivers and streams. Relocation has been used to recolonize areas where mussel populations have been eliminated by prior pollution events, to remove mussels from construction zones and to re-establish populations of endangered species. More recently, relocation has been used to protect native freshwater mussels from colonization by the exotic zebra mussel Dreissena polymorpha. We conducted a literature review of mussel relocations and evaluated their relative success as a conservation and management strategy. We found that 43% of all relocations were conducted because of construction projects that were forced to comply with the Endangered Species Act 1973 and that only 16% were monitored for five or more consecutive years. Most (43%) relocation projects were conducted from July to September, presumably a period when reproductive stress is relatively low for most species and the metabolic rate is sufficient for reburrowing in the substrate. The mortality of relocated mussels was unreported in 27% of projects; reported mortality varied widely among projects and species and was difficult to assess. The mean mortality of relocated mussels was 49% based on an average recovery rate of 43%. There is little guidance on the methods for relocation or for monitoring the subsequent long-term status of relocated mussels. Based on this evaluation, research is needed to develop criteria for selecting a suitable relocation site and to establish appropriate methods and guidelines for conducting relocation projects.     

基于模型试验的河床砂砾石层基本特性研究

为了经济可靠地确定深厚覆盖层的基本特性参数,以大渡河双江口水电站坝基河床砂砾石层基本特性研究为工程背景,进行大尺寸模型试验,研究河床砂砾石层的旁压模量和动探击数随密度、级配以及上覆压力的变化规律。根据室内模型试验结果,结合现场旁压试验及钻孔试验成果,推断出坝址区河床砂砾石相关层位的密度,并依此进行砂砾石室内力学试验,获得设计所需力学参数。研究成果可为深厚覆盖层基本特性测试提供新的方法。     

库水波动下库岸边坡地下水浸润线解析解及误差分析

解析法是库岸边坡地下水浸润线计算中便于实际应用的方法,但该方法须基于若干假定并对潜水运动基本方程线性化后才能求解。针对各假定和线性化过程建立不同的地下水渗流数学模型,用解析法和有限元法解答上述数学模型,分析各误差大小及其规律。结果表明：库岸垂直处理带来的误差要小于方程线性化处理和不考虑非饱和渗流带来的误差,而且它们都随渗透系数变大而减小;在三峡库区库水调度情况下,假定库水位等速变化带来的误差对大多岸坡而言可以忽略;计算库岸边坡地下水浸润线时,解析法只适用于水位变化幅度相比含水层厚度较小,且几何边界规则、岩土结构简单、岩土体渗透性较好时的情况。     

SPATIAL AND TEMPORAL WATER QUALITY VARIABILITY IN AQUATIC HABITATS OF A CULTIVATED FLOODPLAIN

The floodplains of lowland rivers contain diverse aquatic habitats that provide valuable ecosystem services but are perturbed when intensively cultivated. Hydrologic, water chemistry and biological (fish) conditions in five aquatic habitats along the Coldwater River, Mississippi, were measured for more than 4 years: the river, two severed meanders that functioned as backwaters, a managed wetland and an ephemeral channel draining cultivated fields. Off‐channel habitats were connected to downstream regions 0.10% to 32% of the dry season and 24% to 67% of the wet season. The median temperatures for the five monitored sites ranged from 18°C to 23°C, the median total solids concentration for all sites was 135 mg L^?1, the median total phosphorus was 0.29 mg L^?1 and the median total nitrogen was 1.56 mg L^?1. Chemical and physical water quality displayed strong seasonal differences between the wet winter/spring and the dry summer/fall periods so that temporal variation consisted of gradual seasonal trends superimposed on strong diurnal variations. All off‐channel habitats exhibited periods of hypoxia and temperatures >30°C during the dry season. Between‐site gradients of water and habitat quality were strongly coupled to water depth and runoff loading. The rehabilitation of one backwater by increasing water depth and diverting agricultural runoff was associated with improved water quality and fish species richness relative to an adjacent untreated backwater. The diversion of polluted runoff and the use of water control structures to maintain greater water depth were observed to be effective management tools, but the former reduces the water supply to habitats that tend to dry up and the latter reduces connectivity. Published in 2011 by John Wiley & Sons, Ltd.     

Changes in Summer Irrigated Crop Area and Water Use in Southeastern Turkey from 1993 to 2002: Implications for Current and Future Water Resources

Changes in summer irrigated cropland acreage and related water use are estimated from satellite remote sensing and ancillary data in semi-arid Southeastern Turkey where traditionally dry agricultural lands are being rapidly transformed into irrigated fields with the help of water from the Euphrates-Tigris Rivers. An image classification methodology based on thresholding of Landsat NDVI images from the peak summer period reveals that the total area of summer irrigated crops has increased three-fold (from 35,000 ha to over 100,000) in the Harran Plain between 1993 and 2002. Coupled analysis of annual irrigated crop area from remote sensing and potential evapotranspiration based estimates of irrigation water requirements for cotton indicate a corresponding increase in agricultural water use from about 370 million cubic meters to over one billion cubic meters, a volume in accordance with the state estimates. These estimates have important implications for understanding the rapid changes in current agricultural withdrawals in Southeastern Turkey and form a quantitative basis for exploring the changes in future water demands in the region. For example, expansion of irrigated lands have led to a steady decrease in potential evaporation due to increased roughness and decreased humidity deficit in the Harran Plain. Assuming that the changes in future evaporation conditions will be of similar nature, water use for irrigation is expected to decrease over 40 percent in future irrigation sites. Incorporating this decrease in overall planning of the irrigation projects currently under construction should lead to improved management, and by extension, sustainability of water resources in the region.     

簸箕李引黄灌区水沙分布及优化调度的经验

灌区利用水沙观测所取得的资料和试验数据，运用水沙运动力学理论，总结分析和揭示了灌区水沙分布的规律和特点。在此基础上，结合灌区的实际运行情况，围绕减少骨干渠道的淤积进行探讨、研究，进而，优化水沙调度方案。该方案实施后，骨干渠道减旅伴效果明显，取得了成功的经验。