水电站AGC与AVC联合优化机组功率分配的思考

随着《华中区域发电厂并网运行管理实施细则》及《华中区域并网发电厂辅助服务管理实施细则》(以下简称"两个细则")正式试运行,发电企业合理使用"两个细则"要求,可有效增加水电站经济运行效益。本文针对"两个细则"中无功辅助服务条款要求,提出水电站侧AGC与AVC联合优化分配机组有功、无功的思路,并通过二滩水电站实际运行数据仿真,证明该分配策略在满足机组安全、稳定运行的前提下,可提高水电站有偿无功辅助服务电量,提升机组经济运行水平。     

某梯级小水电站系统的运行优化调度和经济运行研究

针对河南省境内某梯级小型水电站群工程的实际,在对梯级水库短期优化调度问题进行深入研究的基础上,提出基于整个梯级电站系统最小发电耗水率的梯级电站调度模型和厂内经济运行模型。考虑到影响梯级水库短期优化调度的水量联系、水头联系和下游不稳定流以及影响厂内经济运行的机组台数、机组组合和机组间的负荷优化分配等,采用最低发电耗水率作为优化目标对该梯级电站进行计算,实现了在电厂经济运行的基础上来实现整个梯级电站的优化运行,达到增加发电效益的目的。该研究能够用来指导实际运行。     

双层耦联遗传算法求解流域梯级水电站厂内经济运行问题研究

针对梯级水电站厂内经济运行调度模型约束条件多、求解复杂的问题,提出了一种基于遗传算法的双层耦联求解算法,该算法兼有机组负荷分配和机组组合双重优化的特点,可同时求得厂内经济运行优化调度模型的全局最优解.研制开发了基于此算法的梯级水电站厂内经济运行优化调度程序软件,并且已应用于某流域梯级水电站厂内经济运行实际调度计算中,取得了较高的工程应用价值.     

新安江水力发电厂机组间无功分配优化研究与实践

以新安江水力发电机组在特殊接线方式下机组间无功分配方式为对象,分析机组运行过程中机组间无功分配的关系,从优化厂内无功分配的角度对无功控制策略进行研究和实践。     

Memetic算法在水电站负荷优化分配中的应用

针对求解水电站厂内经济运行中负荷优化分配问题时常出现的收敛性差、易早熟等问题,将基于全局搜索和局部启发式搜索相结合的Memetic算法应用于水电站厂内经济运行负荷优化分配模型,用有限制的初始种群生成法来克服水电站机组不稳定运行问题,采用育种算法作为局部搜索策略。三峡水电站厂内经济运行实例计算结果表明,有限制的初始种群生成法能够避开空蚀振动区的影响,保证机组的稳定安全运行;Memetic算法的全局搜索和局部启发式搜索策略能够扩大寻优范围,优化群体结构,提高算法的收敛能力。     

浅析电力市场中水电站主能量市场与有偿辅助服务联合优化

在成熟的电力市场中,辅助服务将成为交易或竞价品种,主能量和辅助服务联合优化的结果是制定水电企业综合竞价策略的依据,只有合理分配发电资源,才能确保辅助服务成为水电企业新的经济收益来源。讨论并分析了主能量和辅助服务联合优化的问题,包括有功容量和无功容量联合优化、主能量和备用容量联合优化。     

日前市场下发电商机组优化组合研究

日前电力市场下,发电集团经常面临在给定总负荷出力曲线和总备用服务要求下,如何在机组间(厂间)进行合理分配出力/备用容量的优化问题,针对于此,提出了考虑旋转备用服务的日前市场机组组合模型和"基于决策树的动态规划法"的求解方法,并利用该方法进行了具体实例计算,深入分析了旋转备用被调用概率、结算价格和容量对机组组合模型优化结果的影响,为发电集团合理安排日前市场下机组间(厂间)负荷分配或联合调度营运提供了一定的思路和实际意义。     

大型水电站整体时空经济运行模型及其算法

随着经济的发展,电力需求量越来越大,传统的水电站经济运行模型已不能满足要求。根据上述背景提出大型水电站整体时空经济运行模型及其算法研究。构建大型水电站整体时空经济运行模型,采用扩展蚁群算法对机组组合进行优化,依据制定稳定优化表对经济符合进行最优分配,最终实现该模型的运行,并对其有效性进行验证。实验结果显示,模型平均运行效率比传统模型的平均运行效率高出25%,具备极高的有效性。     

基于统一平台的梯级水电站经济调度控制系统

以梯级水电站计算期末蓄水能最大为目标,考虑了站间联合躲避各机组振动区等约束条件,确定了机组开停机与站间负荷优化分配模型协调统一的梯级水电站经济运行算法,提高了梯级水电站实时控制的安全性、经济性和实时性。根据上述研究成果,基于智能水电厂统一平台开发梯级水电站经济调度控制软件一套,并在松江河智能水电厂改造项目中推广应用。     

浅谈万安水电厂厂内经济运行

根据万安水电厂厂内经济运行面临的问题,完善水轮机过机流量实时精确测量,将机组尽可能安排于高效率期间运行,降低单位电能耗水率,以提高水电站经济运行水平。通过水轮机效率试验,获得机组运转特性,绘制机组动力特性曲线,优化机组开停机计划,并确定各机组间最优负荷分配(即最优经济运行方案),完善AGC的经济运行优化功能,获得水力机组及整个水电厂的动力特性等基础数据,建立厂内经济运行的最优数学模型和求解算法,制定厂内经济运行计划,利用水电厂自动发电控制AGC对水电站各机组进行实时控制,实现稳定、高效的厂内经济运行。     

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。     

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。     

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.     

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。     

浅谈天湖水电站水轮机运行故障及处理措施

简述天湖水电站投运以来各种故障的表现形式，分析其原因，提出了相应的处理方法及措施，并对合理利用国内外设备提出建议。