基于数据驱动的水轮机调速系统健康状态预测

水轮机调速系统是水轮发电机组的关键控制系统。运用故障树与专家系统相结合的方法对调速系统可能发生的故障进行诊断,并基于历史数据,挖掘与故障相关的可能因素,对专家系统无法解决的故障进行分析,构建了基于数据驱动的水轮机调速系统健康状态预测系统。     

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。     

多机调速系统状态协同监测与优化控制

介绍了丰满智能水电厂全厂水轮机调速系统状态监测和优化控制。根据全厂水轮机调速系统架构,建立一种多层次多机调速系统健康状态协同监测架构。通过一台设备与总体统计量的比较分析发现变化异常情况。多机协同监测互为补充,可有效解决缺失值补充、离群点检测等问题。对系统运行性能影响特征量之间的关系进行分析,发现相关关系,提升部件健康状态诊断的准确性。对各待监测量分别建立监测模型作为集成学习的元学习器,多机构建的模型共同进行集成判断,得到更为可靠和稳定的判别结果。为了发现新故障,提出一种基于孤立森林的新故障多机组协同在线检测方法,以发现未知的新故障。应用水电站容易得到的上下游水位差和导叶接力器行程替代净水头和导叶开度,多机协同寻优水轮机的相关特性曲线,优化水轮机调速系统的开机过程、功率控制和一次调频,标出水轮机振动摆度超标区和超负荷区域,以便调速系统避开这些区域,提高发电运行的安全性。     

智能水电厂调速系统的设计与应用

介绍了丰满水电厂分层分区布置的全厂水轮机调速系统的结构。全厂调速系统智能分析平台通过工业以太网与各水轮机调速系统健康状态监测平台相连,各水轮机调速系统健康状态监测平台通过以太网与水轮机调节器A机PLC、B机PLC以及油泵控制系统相连,还通过RS485总线与油泵变频器通信;各水轮机调速系统通过IEC61850-MMS A网和B网与水电厂一体化管控平台相连,以便共享信息;调速系统关键部件均实现了冗余配置,且增加了监测对象,包括分段关闭装置、事故配压阀、接力器、油压装置和漏油箱等。这种结构便于单机和多机调速系统的协同监测和优化控制。根据反措要求,设计了多功能失电关闭装置、失电分段关闭装置和防水淹型漏油装置,也进行了水轮机调速器和油压装置的反措设计,防范重大事故的发生,提高系统的安全性和稳定性。     

水轮机及其调速系统在低频振荡中的作用

在研究电力系统低频振荡时，传统方法通常忽略水轮机及调速系统的影响。本文提出了水电站单机无穷大系统的低频振荡研究模型，计及了励磁调节系统和水轮机及其调速系统的作用，对不同状态下的特征根进行了比较，并做了振荡模式的相关性和灵敏度分析，结果表明水轮机及其调速系统对电力系统低频振荡模式的影响不可忽略。     

水轮机调速系统建模参数测试理论与应用研究

介绍水电厂水轮机调速系统基本工作原理，描述了调速器建模参数的测试理论，对调速器现场参数测试条件与方法进行研究，为水轮机调速系统建模与仿真提供基础数据，确认水轮机调节系统在并网状态下的时域和频域响应特性。     

水轮机及其调速系统在单机无穷大系统低频振荡中的作用

在研究电力系统低频振荡时,水电站单机无穷大系统的低频振荡研究线性化模型,计及了励磁调节系统和水轮机及其调速系统的作用,运用特征分析法,对不同状态下的特征根进行了比较,并做了振荡模式的相关性和灵敏度分析,结果表明水轮机及其调速系统对电力系统低频振荡模式的影响不可忽略。     

非线性鲁棒控制在大型微机水轮机调速器上的应用研究

从水轮机引水系统、水轮发电机组和电力网络的统一系统模型出发，应用非线性状态反馈的方法得到远程输电系统中水轮发电机组调速系统的非线性鲁棒控制规律，接着研究了鲁棒控制规律在大型微机水轮机调速器上的应用，并和PID控制进行了仿真比较试验，研究了控制规律在远距离输电系统的安全稳定性方面所起的作用。     

水轮机调速器状态监测系统的设计及研究

本文从近年来水电站调速器重要部件的故障分析开始,提出了水电站调速系统状态监测的重要性和必要性。文章给出了典型的调速系统状态监测原理架构,对状态监测的定义、系统组成、数据的上传、存储、分析等做出了详细说明;阐述了监测系统的难点和关键点,如监测设备的范围和信息量、数据的处理及存储、诊断的方法等;并结合实际运行情况给出了调速重要部件电液伺服阀、主配压阀、电磁阀的故障诊断及预测方法,可为水电站的全面状态监测的设计和研究提供有益参考。     

水轮机流道密封结构在线监测与诊断分析

针对水轮机在恶劣环境下长期运行导致其流道密封结构性能降低这一常见问题,在分析水轮机流道密封结构及其故障特性的基础上,提出通过对水轮机顶盖积水—排水特性的实时运行状态监测来辨识水轮机密封部件的健康状态、诊断水轮机密封结构损坏程度,同时采用实时状态数据分析和统计分析对顶盖排水系统进行故障诊断和寿命评估。文中详细介绍了此方法在葛洲坝电厂最优维护信息系统3F机组状态监测与诊断子系统中的应用情况,实践证明该方法具有可行性和实用性,拓展了水轮机故障诊断分析的思路,具有推广应用前景。     

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。     

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.     

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.     

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。     

Automated system for removal and pneumatic transport of fly ash from electric precipitator hoppers

A system for removal and pneumatic transport of fly ash is examined, in which air pulses act on batches (pistons) of ash formed in a duct. Studies are made of the effect of several physical parameters on the force required to displace a piston of ash and these serve as a basis for choosing a system for removal and pneumatic transport of ash simultaneously from several hoppers of an electric precipitator. This makes it possible to separate the ash particles according to size without introducing additional components. Formulas are given for calculating the structural and dynamic parameters of this system and measurements of indirect dynamic parameters are used to calculate the input-output characteristics of the system. In order to optimize the system, configurations for summing several ducts into a single transport duct for pneumatic ash transport are proposed. Some variants of dry ash utilization and the advantages of producing of size-separated particles are considered. __________ Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008).     

The flood pulse advantage and the restoration of river-floodplain systems

The ‘flood pulse advantage’ is the amount by which fish yield per unit mean water area is increased by a natural, predictable flood pulse. Evidence for this increase is presented from tropical and temperate fisheries. It is argued that increasing multispecies fish yield by restoring the natural hydrological regime is consistent with increasing production of other trophic levels and with restoration from ecological and aesthetic viewpoints. When applied to a river-floodplain system, this restoration would provide a large, self-sustaining potential for recreation, commercial exploitation, and flood control. An interim ‘natural flood pulse’ restoration approach is proposed for systems modified for navigation. This approach approximates the natural hydrological regime in a river reach and is intended as a first step in the long process of restoring the watershed.