基于两阶段模型的风光互补系统储能容量配置优化方法

为提高风光互补系统供电经济性,根据风光互补系统的运行特点,第一阶段以风光互补系统技术特性为约束,计算负荷缺电率和新能源弃用率,并将其作为第二阶段的边界条件。第二阶段以储能初始投资年均成本最小作为目标函数计算风光互补系统的最优储能容量配置。结果表明,合理配置储能容量可以有效减少系统的投资成本。     

风光水互补发电系统发电效率分析

笔者主要探讨风光水互补发电系统发电效率的分析。由于煤石油天然气等资源日益枯竭,清洁能源的利用变得非常重要。风光水互补发电系统是一种将风电、光伏发电、水电结合的发电方式,其发电效率对于清洁能源的发展具有重要意义。笔者首先介绍了风光水互补发电系统的原理和构成,然后分析了不同风光水互补发电系统中各种因素对发电效率的影响。最后,提出了一些提高风光水互补发电系统发电效率的建议,为清洁能源的发展做出一定的贡献。     

风光水互补系统发电效益-稳定性多目标优化调度

风光水互补系统联合运行是解决风电、光电等间歇性能源消纳的有效方法之一,但互补系统的发电效益与稳定性存在矛盾关系,如何分析系统的出力互补特性并解析效益-稳定性关系是本研究解决的关键科学问题。本研究在雅砻江流域风光水互补示范基地上开展研究工作,采用互补系统总发电量最大、出力过程变异系数最小为目标构建效益-稳定性多目标优化调度模型,采用径流、风速和太阳辐射强度等作为输入,分析调度方案出力互补特性与目标关系。研究结果表明:效益-稳定性目标之间的关系为总发电量越大,变异系数越大,出力过程平稳性越差;互补系统在日内时间尺度上的互补关系为从夜间到日间再到夜间,光电出力从零逐渐增大再变为零,风电出力从大变小再变大,存在日内互补关系,水电能源依靠调节能力可有效互补平抑风电和光电出力。     

水火电联合调峰电力电量平衡优化模型

水火电联合调峰情况下,以弃水电量最小为原则的电力电量平衡计算未考虑火电站的经济运行方式,存在一定的不足。从电力系统经济运行角度出发,以火电站运行煤耗成本与水电站弃水电量机会损失成本之和为系统总成本,建立了总成本最小的电力电量平衡优化模型。模型求解方面,考虑到机组组合优化和经济负荷分配问题的求解难度,采用了双层嵌套寻优算法,外层采用枚举法进行机组组合遍历寻优,内层采用等微增率法进行煤耗最小寻优。以云南省滇中区域电网典型日平衡计算为例,分别按照总成本最小模型和弃水电量最小模型计算了水火电调峰运行过程。计算结果表明：前者虽然弃水电量机会损失大于后者,但火电煤耗成本远小于后者,系统总成本更小。     

风光水发电系统联合调度规则提取

为提高风光水发电系统的经济效益,需提取系统调度规则实现风光水互补运行。建立以系统总发电量最大为目标的确定性优化模型,采用动态规划逐次逼近法(DPSA)求解模型;初选决策变量和影响因子属性集,基于灰色关联度(GRA)确定影响因子;建立BP人工神经网络模型提取调度规则。以雅砻江下游梯级水库群为研究对象,计算结果表明:对于1953年～2011年实测径流系列,考虑水电、风电和光电互补性的联合优化调度可提高系统的多年平均年发电量;在风光水联合优化调度基础上提取的调度规则能较好地保持确定性优化调度的发电效益。     

乌鲁木齐地区风光互补发电系统优化研究

风光互补发电系统的设计和运行需要考虑地理位置、气象条件、设备特性和负载要求等因素。目标是合理配置各组件,充分利用两者的互补性,达到提高系统运行可靠性和经济性的目的。本文对乌鲁木齐地区风光互补发电系统进行了优化研究,首先利用气象观测数据分析风能资源和太阳能资源状况,然后根据风力发电机和光伏电池的功率特性分别建立能量输出模型,最后根据最优化理论建立风光互补发电系统优化设计的数学模型,并利用遗传算法进行了求解分析。结果表明本文提出的优化方法具有一定的合理性。     

楚雄风光水互补协调运行及新能源建设运行管理初探

在分析了楚雄地区风、光、水资源特性及发电特性后,证明楚雄短中长期互补是可行的。然后提出实时分组风光水互补概念、分组策略及软件实现,并介绍了风光水互补控制策略。在短期风光水互补中,提出电站群日计划曲线制作方法和调度给定发电计划下的最大效益模型;中长期风光水互补中,侧重资源的互补性,在天气预报和多年经验基础上,以发电量最大为目标,制作中长期发电计划。文章还对风、光新能源的建设、运行管理经验进行探讨。     

风光水互补发电系统送出能力分析

针对风光水互补发电系统分析了影响系统送出能力的主要因素,构建了以接入风光规模最大为目标的互补送出能力分析模型。以金沙江上游叶巴滩电站及其周边风光资源组成的风光水互补发电系统为例,研究互补送出能力的敏感性。研究表明:系统中风光水出力具有较好的互补性,其中风电与水电的年内互补性最好;系统送出能力对系统送出通道容量最为敏感,对系统允许弃风光率的敏感性次之;当系统风光容量比例取0. 95,允许弃风光率取5%,系统送出通道容量取水电站装机规模224万k W时,叶巴滩电站可接入风光总规模80. 3万k W,可送出风光电量13. 05亿k W·h,系统送出通道利用率可提升6. 65%。     

黄河上游青海水风光蓄一体化发电系统研究

随着双碳目标加速落实与黄河流域生态保护和高质量发展规划实施,统筹推进水风光一体化基地建设并构建多能互补发电系统,能提升跨省跨区电网错峰支援和余缺互济能力。通过采用归纳梳理的方法对黄河上游青海省水风光资源和多能互补著绩进行了分析,结果表明：青海南部水电势能、北部太阳能和西部风能资源潜力较大,但各种新能源随开发规模的扩大其可开发潜力呈下降趋势。青海省规划的风光容量配比为0.6∶0.4,2025年情景下水电与风光配比为1∶1.2,2035年情景水平下为1∶1.25。此外,在电网系统中尽可能少接风电多接光伏且弃电率保证在5%以内对电网稳定运行和投资成本具有正反馈作用。     

水风光互补系统灵活性需求量化及协调优化模型

利用水电等灵活性调节电源平抑间歇性风光发电是解决新能源规模化并网消纳的重要途径。依托云南电网实际工程,提出灵活性需求量化方法,采用分位点确定了风光电站集群出力概率分布的取值变化区间,生成不同概率的出力场景集,以量化描述面临计划的灵活性需求;集成6种灵活性调节指标,构建了灵活性裕量期望最大和不足期望最小模型,能够动态适应不同场景的水风光互补调度需求。通过实际数据分析了灵活性需求量化的准确性,以及不同来水条件、新能源接入比例、风光装机比例、水电机组特性、调峰需求对灵活性的影响,与预留备用容量方法相比,本文模型能够根据灵活性需求变化给出多类型电源互补调度方案。     

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。     

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。