定、变速抽水蓄能机组调度决策关键技术研究

针对抽水蓄能定速和变速机组不同的运行特性进行了分析,构建了基于混合整数线性优化的抽水蓄能与其他各类型机组的联合调度模型。模型计及了机组的运行工况、水库库容、循环类型等抽水蓄能机组约束,还考虑了频繁启停和稳定区外运行给机组带来的损耗问题。利用CPLEX求解器对模型进行求解,省级电网的实证算例分析表明,模型可在考虑机组经济寿命前提下,有效安排抽水蓄能定速和变速机组调度运行出力,充分发挥机组调峰填谷和消纳新能源的作用;变速机组因其灵活的调节特性,能更好地改善系统内其他机组运行条件和促进新能源消纳。     

基于系统运行模拟的抽水蓄能变速机组容量配比优化研究

抽水蓄能机组对于保障电力系统安全、稳定、高效运行作用显著,特别是抽水蓄能变速机组,具有抽水功率可调、运行效率提升和调节范围加宽等优势。考虑到抽水蓄能变速机组投资成本相比恒速机组较高,进行变速机组容量配比优化研究十分必要。本文建立基于电力系统安全约束机组组合的抽水蓄能变速机组容量配比优化模型,可以在给定的区域电源规划方案下,给出新建变速机组占所有新建抽水蓄能机组的经济最优比例。针对西部某区域的算例分析表明,新建抽水蓄能变速机组容量配比在33%左右时,系统运行效益最优。     

海水可变速抽水蓄能与风电联合运行优化研究

海水可变速抽水蓄能是国内尚未应用的新技术，是消纳海上风电、提高沿海及海岛电力系统可靠性的新思路。以经济效益最大化和输出功率波动最小化为目标，提出考虑分时电价、变速机组运行特性的多层次约束条件，建立海水抽水蓄能与风电联合系统运行优化模型；引入NSGA-Ⅱ算法结合罚函数求解；以广东万山群岛微网系统为例，定量对比了含可变速和定速机组的海水抽水蓄能与风电联合系统运行性能，阐明了可变速技术优势。结果表明：在一个日调节周期内，相较于同容量下的常规抽水蓄能与风电联合运行系统，可变速抽水蓄能与风电联合运行系统可提高经济效益4.16%,降低输出功率波动12.10%,减小弃电量26.78%,提高风能利用率1.69%。研究成果对探寻适合中国沿海地区和海岛的海水抽蓄系统发展模式具有借鉴意义。     

碳达峰背景下抽水蓄能-风电联合系统建模及有功功率控制特性研究

随着"碳达峰,碳中和"目标的提出,风电并网规模日益扩大,抽水蓄能电站在风电出力消纳上将发挥越来越重要的作用。建立抽水蓄能-风电联合系统仿真模型是研究抽水蓄能电站消纳风电波动出力的重要手段。针对现有多能互补模型中的抽水蓄能机组模型通常只适用于小波动过渡过程、且通常简化风电机组动态发电过程的问题,为了进一步揭示联合运行过程中抽水蓄能机组和风电机组的动态调节特性,介绍了抽水蓄能-风电联合系统数值仿真模型架构,建立了一种能模拟抽水蓄能机组全工况范围和反映风电机组发电特性的水风互补联合运行系统仿真模型,重点研究了联合系统在有功功率控制下的动态响应特性。仿真结果表明系统在功率跟踪模式和功率平滑模式下均能较好平抑风电出力波动,并显示出水流惯性限制了抽水蓄能机组的响应速度,可为风电大规模并网下的抽水蓄能机组控制提供技术支持。     

抽水蓄能计算机监控系统新技术展望

当前,抽水蓄能行业都在积极探索抽水蓄能电站计算机监控系统与电厂数字化、智能化业务的结合应用,推动智能抽水蓄能电站技术体系的完善与改进.另外,变速抽水蓄能机组具有一定程度的异步运行能力,能通过相位、幅值控制可获得快速有功功率和无功功率响应,有利于电力系统稳定运行,开展变速抽水蓄能机组监控系统的研究,也是一个新的课题和方向...     

大型抽水蓄能机组的变速运行

潘家口蓄能机组将是世界上第一台进行变速运行的大型抽水蓄能机组,目前正在安装,预计1990年底可进行整机调试。该机是采用变频器来实现变速运行的。用变频器作同步电动机的启动国外已有成功经验,但用于大型抽水蓄能机组作变速运行尚属首次。因此。有关潘家口抽水蓄能机组的变速运行已引起有关方面的关注和重视。     

抽水蓄能电站的节煤效益

抽水蓄能机组在电网低谷负荷时作抽水负荷，降低火电机组的压火损耗；电网高峰负荷时顶替火电机组出力调峰。但目前国内对抽水蓄能电站的节煤效益进行定量模拟计算研究尚较少。为此，根据安徽电网年负荷曲线实际资料，模拟计算、分析抽水蓄能电站的运行工况和燃料成本，得出在电网中适当建设抽水蓄能电站具有节煤效益的结论。     

抽水蓄能变速机组前期规划策略初探

介绍了抽水蓄能变速机组在电网中的优势,并分析探讨了变速机组在负荷集中区域、新能源集中区域以及特高压受端区域电网中所起的作用。通过对抽水蓄能变速机组的规划研究发现,负荷集中区域、新能源集中区域以及特高压集中区域,由于其特殊性对电网的安全稳定要求更高,更需要抽水蓄能变速机组的加入。以京津及冀北电网为典型电网,选取尚义抽水蓄能电站作为典型案例,对电网对变速机组的需求进行了验证,结果表明,可变速抽蓄机组调节精度高、响应速度快、调节幅度大,有利于促进京津及冀北电网坚强智能电网的建设,且从系统经济性及长远看,变速机组还是比较经济的。     

变速抽水蓄能机组有功功率与转速协调控制研究

针对变速抽水蓄能机组有功功率与转速之间的协调控制问题,分析了变速抽水蓄能机组有功功率与转速协调控制原理,提出了变速抽水蓄能机组有功功率与转速协调控制方法,并搭建了变速抽水蓄能机组控制系统联合RTDS仿真试验平台,对变速抽水蓄能机组有功功率与转速协调控制方法进行了联合仿真试验验证。试验结果表明:发电工况有功功率与转速协调控制宜采用交流励磁系统转速闭环和调速器有功功率闭环控制方式,抽水工况有功功率与转速协调控制宜采用交流励磁系统转速闭环和调速器开度闭环方式。     

变速抽水蓄能机组运行转速对水泵断电工况的影响规律研究

【目的】变速运行技术是抽水蓄能行业重要的发展新方向，为了研究变速抽水蓄能机组不同初始运行转速对水泵断电工况的影响规律，【方法】分别对变速抽水蓄能机组在不同初始转速下发生水泵断电的导叶关闭和导叶拒动工况进行数值模拟，分析了该水力过渡过程中各关键物理量的变化规律、调节保证极值以及工况点轨迹演变规律。【结果】结果显示：变速抽水蓄能机组在允许的初始运行转速变化范围内(96%～108%)发生水泵断电。若导叶关闭，则该算例机组的蜗壳压力升高率、尾水管压力降低率、转速反转率变化范围分别在2.20%、3.28%、5.20%以内，不同初始运行转速对应的工况点轨迹线前期差别较大，而在进入水泵制动工况后的过渡过程中则接近重合。若导叶拒动，则不同初始转速对应的工况点轨迹线均与导叶初始开度的等开度线重合。【结论】结果表明：不同初始转速对应的流量和力矩在后续的过渡过程中的变化规律和变化幅值近似，蜗壳压力升高率、尾水管压力降低率、转速反转率变化范围均小于导叶关闭情况下相应的变化范围，分别在1.13%、2.98%、0.4%以内。研究成果可为我国变速抽水蓄能机组的实际投运提供一定技术支持。     

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。     

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。     

Fish assemblage response to recent mitigation of a channelized warmwater stream

Various designs of low‐head dams are used to rehabilitate streams or forestall upstream channel incision after channelization. We report on the efficacy of using notched sills and grade control structures (GCS) to restore the fish assemblage in Luxapallila Creek, Mississippi. We tested the null hypotheses that habitat variables and species richness, evenness, and assemblage structure would not differ among: (1) a channelized segment with no modifications; (2) a channelized segment mitigated by the installation of sills and GCS; (3) a segment upstream of the installations and undergoing channel incision; and (4) an unaltered segment. Although habitat variables changed, neither species richness, evenness, nor fish assemblage structure differed between mitigated and channelized segments with both exhibiting less richness and different assemblage structures than the unaltered segment. Lack of differences in species richness between the incised and unaltered segments suggest that the GCS may have halted the negative effects of upstream channel incision before species were extirpated. Conspicuous habitat differences between the altered (channelized and mitigated) and unaltered segments were lack of backwaters and canopy coverage and finer substrates in the altered segments. Our results suggest a more comprehensive rehabilitation strategy is required in Luxapallila Creek. Published in 2003 by John Wiley & Sons, Ltd.     

NUMERICAL STUDY OF WAVE EFFECTS ON SURFACE WIND STRESS AND SURFACE MIXING LENGTH BY THREE-DIMENSIONAL CIRCULATION MODELING

1. INTRODUCTION Coastal and continental shelf regions are characterized by intensive interaction between wave and current. These regions are of great economic significance to mankind. Therefore, the modeling of wave and current as well as their mutual int…