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随着现代电力系统误操作事故的频发,微机防误闭锁系统在各电压等级的变电站得到了广泛的应用。本文介绍了变电站微机防误闭锁系统的工作原理分析,通过对比传统电器防误技术,结合生产实际介绍了变电站微机防误闭锁系统在使用中经常出现的问题,并对微机防误闭锁系统运行管理措施进行了分析,以期为微机防误闭锁系统在变电站的安全运行管理提供借鉴和参考。 相似文献
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在变电站自动化程度发展到以太网通信条件下,电力操作安全防误也随之出现很多新的问题。以变电站倒闸操作为研究对象,以IEC 61850标准中控制模型为研究基础,分析认为以太网通信条件下变电站操作将是基于网络的访问过程,其防误措施主要表现为对访问行为的规范,包括控制对象对访问权限的判定。提出了网络环境下遥控操作防误闭锁的有效解决方案,能很好地实现防空程以及与当前微机防误系统类似的防误功能。 相似文献
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介绍在集控中心建立下辖所有变电站五防数据管理的专用五防服务器,巡检中心建立五防主机(与目前柳州供电局监控系统模式相同),实现网络化集中式管理.在集控模式下,集拉中心的五防服务器统一管理下辖各受拉站的五防数据.受控站通过网络上传本地的一次设备的运行状态给集控中心,并可以接收集控中心下达的操作票,实现任一点开票、任一点接票... 相似文献
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分析了现有闭锁装置的不足,阐述了可编程控制器(PLC)基础上的网络化微机防误闭锁系统。系统采用多台西门子S7-200进行电气量信号采集和操作闭锁执行功能,完成对现场电气设备的控制;控制主机做为系统的控制和综合判断中心,利用RS-485通信线与PLC进行通信,实现现场设备的实时监控。该系统经过在实际中的应用,完全符合电力系统的安全运行要求,满足变电站运行中防误操作闭锁的要求。 相似文献
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分析电气误操作产生的原因,提出减少误操作的措施,并结合澜沧江集控中心的实际情况,详细介绍了在监控系统上采用各项管理措施和技术方法来实现防误闭锁功能,为集控中心防误闭锁功能提供了较为完善的制度保障及技术支持. 相似文献
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本文主要介绍了葛洲坝二江电厂的计算机防误操作闭锁系统基本原理、功能、设计 应用效果;计算机防误操作闭锁系统主要由操作指令锁和操作程序闭锁估部分组成;操作指令 通过“安全分析系统”来实现的,防止操作指令的误发;操作程序闭锁是计算机对设备操作过程中的每一项操作均实行严格的安全条件检查,防止由于各种因素引起的误操作。 相似文献
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分析了集中式和分布式变电站程序化控制实现方案的优缺点,提出了一种不依赖于站级网络通信协议、以间隔层智能电子设备(IED)为核心的分布式变电站程序化控制实现方案,操作票的存储、执行及操作逻辑的判断均在IED中实现,程序化控制过程中需要操作其他IED则请求站控层设备执行。该程序化控制方案已在CSC-2000变电站自动化系统中实现。该方案既适用于站级网络协议为IEC 61850等国际标准的变电站自动化系统,也适用于站级网络协议为以太网IEC 60870-5-103协议、 CSC-2000协议等企业标准的变电站自动化系统,尤其适合在IEC 61850标准还没有完全普及的过渡时期采用。 相似文献
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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。 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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V. K. Konovalov O. V. Yashkin V. V. Ermakov 《Power Technology and Engineering (formerly Hydrotechnical Construction)》2008,42(2):105-109
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.
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Translated from élektricheskie Stantsii, No. 2, pp. 26–30 (2008). 相似文献
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Peter B. Bayley 《河流研究与利用》1991,6(2):75-86
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. 相似文献