基于最优潮流理论的风电、梯级水电短期联合优化调度

为了协调多电源短期联合调度方案经济性与可靠性之间的关系,需要建立高效、实用的模型,并采用新型优化算法对调度模型进行求解。本文基于最优潮流理论建立多电源短期联合优化调度模型,在目标函数中考虑电力系统的经济性与可靠性指标,在约束条件中考虑电源约束条件和电网约束条件。在计算发电系统可靠性时,采用基于运行状态的瞬时可靠性评估法,有效避免了传统可靠性评估方法在评估风电等波动性较大电源方面的不足。最后以IEEE-30节点系统为例验证本文提出的优化调度模型和算法,结果表明,本文的联合调度策略可提高系统的可靠性指标,降低风电场的弃风量,增加梯级水电与风电的上网电量,保证火电输出功率的平稳性。     

互联电网共享运行备用可靠性评估

提出了互联电网共享运行备用可靠性评估算法和指标。基于能量管理系统提供的电网实时运行信息,计及区域联络线约束、在线机组状态、网损、负荷波动等随机因素对运行备用可靠性的影响,将分区评估与全网评估相结合,评估了各子区域对全网可靠性的影响。华东电网的评估算例表明,该算法可以定量评估实时系统各子区域对维持全网可靠运行所作出的贡献,为共享备用分摊计算提供依据。     

推力轴承在线监测系统在仙游抽水蓄能电站的应用

通过在仙游抽水蓄能电站加装GMH550推力轴承在线监测系统,实现了对推力轴承运行状态、健康状况实时在线监测,并对推力轴承运行中存在的潜在缺陷和问题进行评估和预判,确保推力轴承运行的稳定性和安全性。主要功能涵盖了对推力轴承运行状态的全面监测、对推力瓦与镜板间油膜厚度的实时监测及报警、推力轴承运行状态自动评价及故障诊断和推力轴承检修状态自动评价。介绍GMH550推力轴承在线监测系统与功能和在仙游抽水蓄能电站的实际应用与效果,为推广推力轴承在线监测系统在行业的发展做出一份贡献。     

水工金属结构远程监控及安全管理系统研究

针对水工金属结构存在的缺乏实时在线监测、监测数据存储及传输方式落后、缺少远程共享管理平台及实时安全评估机制等问题,构建了一套可支持数据动态采集、数据高效存储及实时传输、实现远程监控及实时安全评估的水工金属结构远程监控及安全管理系统,建立了系统的体系结构和运行流程。在此基础上,对基于信息采集终端的运行状态数据采集与收发技术、基于互联网技术的数据传递方法及管理平台和分类分层方法以及安全度概念的安全评估机制等关键技术进行了研究。该系统已成功应用于云南某水电站,取得了良好的效果。     

电力自动化系统UPS供电方案可靠性

不间断电源(UPS）紧急供电系统是电力自动化系统安全可靠运行的根本保证，因此有必要对其可靠性进行定量评估分析。文中将UPS系统分为13个功能模块,并根据各模块特点，建立了相应的精确多状态Monte-Carlo可靠性数学模型，创建了基于模块的UPS系统故障树。在此基础上提出了基于时序Monte-Carlo仿真的UPS系统可靠性指标求解及灵敏度分析方法。以一实际UPS系统为例，应用所提出的方法对其可靠性进行评估，获得了最优的可靠性增强措施。该方法不仅适用于电力自动化系统UPS供电方案，也适用于其他各种紧急供电系统的可靠性定量分析。     

电力系统在线安全稳定评估及决策技术的研究

阐述了电力系统在线安全稳定评估及决策的概念及其对电网预防控制、暂稳控制、电压稳定控制等方面的重要作用，认为电力系统在线安全稳定评估及决策是今后电网稳定运行和控制的发展方向。对实现在线评估及决策的条件进行了分析和评述，指出电力系统运行状态数据采集的快速性、同时性、可靠性是实现在线评估及决策系统的重要基础，提出了构建电网统一数据平台的设想和建议，并介绍了福建电网在线决策系统的工程实践。     

智能化控制在引水隧洞斜井提升机电控系统的应用

文章对滇中引水工程香炉山隧道2号施工斜井提升机普通电控、PLC及变频电控三种方案进行了详细分析研究,建立了基于双PLC控制的变频提升机电控系统,并进行了应用与关键技术实践验证。结果表明：将PLC控制功能与全数字变频技术相结合,极大提高了提升机运行的稳定性和可靠性,调速精度高,能够实现电机满功率向电网进行能量回馈。基于S7-300的双PLC主控制系统是整个控制系统的核心,能对提升机电控系统的实时运行状态进行采集,从而对电机进行精确、稳定的控制;通过位移传感器、摄像头等多传感器在线监测,实现了提升机系统闸瓦磨损监控、信号通信、视频监控与远程故障诊断。     

火电厂的实时状态监测系统与故障诊断

针对国内大多数火电厂现场设备控制的现状，提出一个经济型实时状态监测系统方案，在充分利用原有设备的前提下，采用集散控制系统(DCS)结构和FIX组态软件实现某厂各主要站点的集中监视和统一管理。在此基础上，利用实时状态数据对主要设备运行状态进行评估，对设备故障进行预测和诊断。现场运行结果表明：该系统对火电厂的现场设备实现了有效的集中监视，并可对主要设备进行故障预测和初步诊断。     

基于在线辨识的实时最优励磁控制器

设计了一种在线实时最优励磁控制器(RTOEC)，其辨识器能够由发电机运行状态的变化采用非线性最小二乘法辨识法准确辨识出单机无穷大模型中的系统参数，从而可根据辨识结果及其系统所遭受的扰动，通过线性最优控制理论实时计算出线性最优励磁控制的反馈增益矩阵，以适应系统当前的运行点和所遭受的干扰。仿真结果表明，所设计的RTOEC能够适应系统运行状态的大范围变化，在大小扰动下均表现出良好的控制性能，有效提高了电力系统的静态和暂态稳定性。     

基于数字化模型的水轮机调速系统状态监测与分析

从状态检修角度出发，提出了基于数字化模型的调速系统状态监测与状态分析方法。该方法通过调速系统设备分析确定了测点布置和数据采集方案，在状态监测的基础上，以机组运行工况为线索，结合调速系统数字化模型对水轮机调速系统设备进行状态评估，采用事件触发和约束传播机制进行设备故障诊断，并以可视化模型指示调速系统设备健康状态和变化趋势，为实现调速系统状态检修打下基础。     

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。     

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。     

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.     

基于BP神经网络-马尔科夫链模型的隧道围岩位移预测

在隧道工程施工中,围岩位移预测起着很重要的作用。将BP神经网络-马尔科夫链模型引入到隧道围岩位移预测中来,通过对训练样本的学习,利用BP神经网络实现了对位移时间序列的滚动预测,同时得到了实测值与预测值的相对误差;在此基础上利用马尔科夫链对相对误差进行修正,有效地提高了预测结果的精度。并将该模型应用于某公路隧道拱顶下沉位移时序预测中,结果表明该模型具有精度高、科学可靠的特点,为隧道围岩变形的预测提供了新的途径。     

Short communication. Pipelines as a refuge for freshwater snails

In the lower River Murray, Australia, populations of gastropods have declined markedly over the past 40 years. Of the native fauna of about 18 species, only the ancylid Ferrissia petterdi remains common (but in patches), and another five species feature in sporadic local resurgences. Until recently the viviparid Notopala was thought to be extinct. The introduced physid Physa acuta is widespread, but in low numbers. The decline probably is associated with flow regulation, high turbidity and the introduction of common carp. Snail populations have persisted, however, in irrigation pipelines fed from the river, where they periodically cause blockages. This paper reports the discovery of the only known populaion of Notopala hanleyi in a pipeline where the inner wall accumulates microbial and other organic matter, providing high quality food for snails. In the Murray before regulation most of the periphytic biomass was probably microbial, as fluctuating water levels would have maintained littoral communities in a highly productive, early state of succession his postulated that, by stabilizing seasonal water levels, regulation has promoted the production of filamentous green algae, an inferior food source, and so displaced snail populations from the open aquatic environment.     

Spatio‐temporal variation of gross CO2 and CH4 diffusive emissions from Australian reservoirs and natural aquatic ecosystems,and estimation of net reservoir emissions

Carbon dioxide (CO₂) and methane (CH₄) diffusive emissions were measured during two field surveys in Queensland and Tasmania, Australia, using the floating chamber method. Bubbling and degassing emissions in 2010 were estimated in Koombooloomba Dam reservoir using only inverted funnels and gas concentrations, respectively. A total of 14 reservoirs and 16 rivers and lakes were sampled from 2006 to 2010. Spatial variation was substantial within each water body, as well as between them. The main drivers of diffusive emission variation were physiographic region and climate, with a clear demarcation being observed between diffusive emissions from tropical Queensland and temperate Tasmania, and between the humid West Coast Range (Tasmania) and dry Central Plateau (Tasmania). Higher CO₂ and CH₄ diffusive emissions were observed during the dry season, when long water residence times would promote organic matter degradation. Estimated total gross emissions, including diffusive, bubbling and degassing emissions, for Koombooloomba Dam reservoir were about 1.5 × 10⁶ t CO₂eq km² per year, or 24 × 10⁶ t CO₂eq per year. This corresponds to a plant emission factor of 3.18 kg CO₂eq MWh^?1. Using an estimate of terrestrial emissions derived from literature data for the Tully River catchment area, rough estimated net emissions from the catchment area are about 44 kt CO₂eq per year, or 5.83 kg CO₂eq MWh^?1, which is in the lower range of the studied reservoirs.     

浙江省水域调查录入系统的设计和应用

浙江省水域调查录入系统将调查数据与电子地图相整合,对分类水域数据进行统计计算,并对输入数据进行合理性和完整性检查,得到调查范围内现有水域的详细数据,实现了水域调查数据输入、计算、统计和查询的数字化管理,提高了工作效率和工作质量,为各地下阶段水域保护规划编制和水域管理工作提供了数据支持。对该系统的设计原则、功能和技术设计等作了介绍。     

基于CT-连续加荷水泥乳化沥青混凝土细观损伤规律研究

利用CT技术对水泥乳化沥青混凝土的细观损伤过程进行实时扫描观测,获得了混凝土试件在连续加荷下的CT图像。通过采用直观分析法、CT数分析法、CT数与损伤变量关系3种方法分析表明,水泥乳化沥青混凝土的破坏过程可分为压密、扩容、裂纹扩展、破坏4个阶段,同时混凝土在受压过程中具有韧性,在极限荷载之前各断面处于压密和微扩容的强化阶段,极限荷载之后混凝土从损伤到破坏发展比较平稳。