GOOSE报文过滤方法研究

面向通用对象的变电站事件（GOOSE）是IEC 61850标准用于解决智能电子设备（IED）之间实时信号通信的多播通信机制，但标准中推荐的多播报文过滤方法在实际工程中不具备可操作性。分析和比较了3种多播报文过滤机制的特点，认为静态配置交换机多播过滤是目前IEC 61850变电站应用GOOSE切实可行的方案，提出了交换机配置定值化管理的概念。交换机配置定值化管理是数字化变电站的必然趋势。IEC 61850标准应采纳统一的动态多播地址管理协议实现交换机动态多播地址过滤，以简化变电站网络设备的管理。     

基于过程总线的母线保护通信体系结构

合理地设计变电站过程层网络的拓扑结构，最大程度地实现信息共享，并保证各种保护、控制系统的可靠性，是数字化变电站发展所面临的一个重要问题。介绍了过程总线的相关技术，分析了采样值（SAV）报文和面向通用对象的变电站事件（GOOSE）报文发布者/订阅者通信模式的2种具体实现方式，提出了3种基于不同过程总线的母线保护通信体系结构，并利用OPNET Modeler软件进行了仿真分析。仿真结果表明了所提出的通信结构的可行性，通过比较分析得出了各种通信结构的适用范围，对过程层通信网络的设计具有一定的参考价值。     

数字化变电站中双网控制策略

IEC制定的变电站内通信网络和系统标准体系（IEC 61850）中没有涉及双网通信、装置与操 作箱控制通信等内容,显然其不能满足大部分数字化变电站可靠运行的要求。通用面向对象的变 电站事件（GOOSE）直接基于ISO/IEC 8802-3以太网协议进行数据传输,有着较高的传输效率,是 数字化变电站的主要特点之一。文中描述的数字化变电站中双网控制策略是基于GOOSE协议的 双网控制策略,该策略不但使系统控制具有快速性和冗余性,也提高了系统控制的安全性和可靠 性,满足了数字化变电站各种控制应用需求。数字化变电站中双网控制策略可作为IEC 61850的 补充。     

变电站GOOSE报文在IED中的实时处理

报文的通信延迟包括传输延迟和处理延迟2部分。IEC 61850标准将面向通用对象的变电站事件（GOOSE）报文直接映射到数据链路层，能有效减少传输延迟。文中对GOOSE报文在变电站智能电子设备（IED）中的处理延迟进行了研究。分析了前后台方式的嵌入式系统在变电站IED中处理实时报文方面的不足，提出在IED中采用具有强实时内核的操作系统，并针对IED中实时报文和非实时报文混合处理环境需求，在RTAI实时操作系统上设计了保障GOOSE报文处理实时性的方案。实验验证了该方案的有效性和实用性。该研究结果对于使用IEC 61850的变电站IED过程总线通信设计具有参考意义。     

数字化变电站网络仿真平台探讨

通信网络设计是数字化变电站系统设计的核心内容之一，直接关系到数据传输的实时性和变电站各种功能的实现。文中提出了利用网络仿真平台对变电站通信网络进行设计的构想，分析了在数字化变电站不同的发展阶段，通信网络设计的主要内容和网络仿真平台的主要功能及意义，介绍了其结构和仿真流程，重点讨论了仿真模型、仿真内核、通信分析器等开发过程中需要解决的几个关键问题。     

基于IEC 61850 GOOSE技术的继电保护工程应用

从继电保护可靠性、速动性以及运行检修、工程设计的要求出发,通过分析IEC 61850提供的通用面向对象的变电站事件（GOOSE）快速报文机制和保护装置硬件结构、软件逻辑,对GOOSE技术应用于继电保护的关键技术,如保护装置GOOSE网口设置、智能操作箱的应用、GOOSE报文的数据处理、运行检修“隔离”措施以及GOOSE配置和工程设计等进行了研究分析,给出了数字化变电站GOOSE技术继电保护应用方案,并已在实际工程中得到了应用。     

基于VxWorks系统的GOOSE实现与可靠性分析

面向通用对象的变电站事件（GOOSE）模型是IEC 61850对数字化变电站的重要贡献,其出发点是变电站自动化功能的分布式实现。通过分析VxWorks操作系统内核的特点,提出了基于VxWorks的IEC 61850 GOOSE发布的实现方案。GOOSE发布任务基于VxWorks事件组,采用事件驱动方式处理GOOSE初始发送、变化发送、快速重发和周期重发。给出了各GOOSE发送控制块共享的高精度定时器的使能和关闭方法。分析了VxWorks网络重发的实现原理,提出了新添加GOOSE协议的重发送实现方式。     

数字化变电站继电保护的GOOSE网络方案

根据数字化变电站继电保护的面向通用对象的变电站事件（GOOSE）需求,针对速动性分析了网络传输延时后提出了改进方法,并针对可靠性和安全性分别分析了不同冗余方式和交换机分配模式的特点。提出根据系统一次接线形式及继电保护配置特点合理规划继电保护GOOSE网络方案的方法,并给出了典型接线形式下的GOOSE网络方案。此外,应根据一次接线形式及继电保护配置特点对交换机虚拟局域网（VLAN）划分、优先级及多播报文过滤进行合理配置。     

新型变电站综合测控装置优化设计

结合特高压电网、数字化变电站的建设,研究变电站自动化系统测控技术,并对测控装置进行优化设计。在变电站信息采集源头进行信息的整合和标准化,使其得到更有效的利用。结合IEC 61850标准中通用面向对象的变电站事件（GOOSE）机制和其他一些新技术,实现过程层网络化信息传输,推动变电站的数字化建设。     

数字化变电站中的通信网关

在数字化变电站的建设和改造过程中,基于IEC 61850的变电站自动化系统与现有系统之间必然存在一个过渡期。为了解决新系统与现有系统的兼容问题,提出了一种数字化变电站中常规智能电子设备的接入方案,设计了一种IEC 61850通信网关,包括配置工具、协议转换器、数据采集过滤器、IEC 61850和过程控制对象链接与嵌入（OPC）客户/服务器等软件模块。另外,基于上述方法开发了一个原型系统,通过测试验证了所采用方案的可行性。     

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。     

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.     

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。     

小湾水库大坝防渗面板及其裂缝的加固处理

小湾水库大坝防渗面板整体抗渗性能差,且存在多条裂缝,通过对面板钢丝网喷涂丙乳砂浆加固处理及其裂缝修补,大坝渗漏量明显减少,且左岸上灌浆廊道内及大坝下游坝面92～93 m高程下廊道入口处原有小股射流全部消失.     

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。