电气检修岗位“逐步逼近追踪式排故技能”应用探讨

随着发电厂、变电站电气装置的功能越来越完善,电气装置的结构日趋复杂。为了精准追踪、快速识别排查隐蔽性较强的电气装置故障,在深度剖析电气装置的原理构成的基础上,提炼出行之有效的"逐步逼近追踪式排故技能":从电气装置的电源检测入手,以功能测试为手段,区分电气装置、功能模块、支路的不同层面逐项进行测试、分析,逐渐缩小范围,步步逼近直至追踪锁定并识别排除电气装置故障。以下只恩水电站备用电源自动投入装置电气故障的识别与排查实践为例,应用"逐步逼近追踪式排故技能"有效地精准追踪、识别排查电气装置故障。     

电压测试法在电气装置故障排查中的应用探讨

针对结构复杂的电气装置中隐蔽性较强的电气故障,往往需要应用电压测试法才能进行识别、排查.通过对常用电气故障的电压特征进行机理分析,并结合下只恩水电站自动重合闸装置电气故障的识别与排查实践案例,介绍了电压测试法在电气装置故障排查中的实际应用.实践结果表明,该测试法操作方便、直观,能有效识别并排查电气装置电源故障、支路断线...     

电力系统电气检修岗位"双向思维排故技能"应用探讨

电力系统电气装置构成复杂,故障原因和故障类型错综复杂。精准地识别故障支路,是电气装置故障排查的关键。笔者通过电力系统电气检修岗位电气装置现场检修案例,介绍了动作过程正向顺序对比分析、逻辑思维逆向追溯锁定目标的"双向思维排故技能"的具体应用。     

大伙房水库非常溢洪道启闭机电器控制实例解析

随着社会的发展和科学进步,电气自动化在工业、农业、水利等各个领域有着十分广泛的应用,正确运用电气图的方法和技巧,对于分析电气线路,排除电路故障有着重要的意义,正确识别和分析电气工程图对电气系统的运行维护、维修改造等是十分必要的,是电气管理工作人员不可或缺的一种职业技能。     

太浦河泵站直流电源装置绝缘降低报警故障的分析与处置

文章以太浦河泵站工程为例,针对绝缘能力降低报警故障的现象,分析故障发生的原因和危害,进而采用拉路排查和绝缘检测手段,成功排除太浦河泵站直流电源装置绝缘降低报警故障。同时,举一反三,对所有隐患部位进行全面排查、检测,并及时改造线路,以防类似故障再次发生。     

水闸闸门开度显示异常故障的分析与排除

闸门控制系统故障将影响着水闸的正常运行,进而影响水闸工程效益的发挥,文章提出了闸门运行时导致闸门开度显示异常故障的原因是多样的,触摸屏、电路传输、编码器、传感器或机械传动装置任一方面出现问题都有可能导致此类故障的发生,通过分析排查确认此次问题出在机械传动装置方面,更换或修复相应的机械传动装置后排除了故障,同时分析了防止此类故障发生的有利条件或者排除此类故障的一般思路方法,确保水闸正常运行,发挥工程效益。     

中国南方电网失步解列装置的配合

通过对南方电网各种运行方式下严重故障的分析计算，结合现有失步解列装置的配置及其设计原理，分析了各种失步情况下电网所配置的失步解列装置的动作及其解列后电网各电气孤岛的稳定情况。南方电网的失步解列装置按照目前的配置在大部分情况下都能正确动作，但存在仅依靠孤立装置难以完全切开失步断面的情况。而失步解列只有断开失步机群之间的所有电气联系线路才能有效消除失步系统间的振荡，避免事故扩大。根据南方电网网情及其现有失步解列装置配置，指出了应在各失步解列装置之间建立通信联系，通过装置配合，可靠地实现系统失步时断开失步机群之间的失步断面，并进一步给出了失步解列建议方案。     

500 kV主变压器总烃含量异常增高分析及处理

利用变压器油中溶解特征气体的组分及含量可识别变压器潜伏性的故障.基于某大型变压器总烃含量增高的原因分析和处理过程,通过产气速率计算、三比值法,结合电气试验,潜油泵检查等方法准确判断变压器故障类型,故障最终得到有效处理.     

一起由消谐装置故障引起的机组跳闸事故分析

文章介绍了一起由消谐装置故障导致的水轮发电机组跳闸事故,结合故障现象对消谐装置和注入式定子接地保护的基本原理进行了阐述。通过一系列试验,对故障原因进行了分析和排查,最终确定了导致事故的根本原因为微机消谐装置故障。     

某变电站主变保护动作分析

以110kV某变电站主变差动保护动作事件为背景,事件发生后通过检查录波文件、波形图、查阅相关试验报告,对动作原因进行分析查找。对故障电气量进行综合分析,进而判断故障区域与故障类型,对于继电保护动作后的电气一次设备检查具有指导意义,同时通过对电气一次设备的检查和故障排除,对理论分析结论进行了验证。     

<Emphasis Type="Bold">Analysis of Spatio-temporal Characteristics and Regional Frequency of Droughts in the Southern Peninsula of India</Emphasis>

A detailed regional drought study is carried out in the southern peninsula of India to characterize the spatio-temporal nature of droughts and to predict the drought magnitudes for various probabilities in the homogeneous drought regions. The method of several random initializations of the cluster centres of the K-means algorithm is suggested for the identification of the initial regions in the context of drought regionalization, which is shown to perform better than the initialization from the Ward’s algorithm and the Ward’s algorithm itself. The peninsula is classified into seven spatially well-separated homogeneous drought regions. The robust L-moment framework is used for the regional frequency analysis of drought magnitudes computed using the standardized precipitation index. The Pearson type III is found to be appropriate for regional drought frequency analysis in six of the regions, while the robust Wakeby distribution is suggested for one region. Low magnitude droughts are frequent and dominant in the northern part of west coast, the north-eastern coast and its adjoining inland region, while high magnitude droughts are less in number and are experienced in semi-arid central part, southern part of western coast, south-eastern part and north-western inland region. The spatial maps of drought magnitudes indicate that at higher return periods (100 and 200 years) the south-eastern part of the peninsula is likely to encounter high magnitude droughts, while the central region is likely to experience the same at lower return periods (10 and 50 years). Hence these regions need to be given special importance in the drought mitigation planning activities.     

Low cost methods of reducing no<Subscript><Emphasis Type="Italic">x</Emphasis></Subscript> emissions from coal-fired boilers

Experiments on coal-dust fired TP-81 boilers at the Irkutsk TéTs-9 heating and electric power plant show that NOx emissions can be reduced by changing the combustion process in the boiler, but that low-pollution burners have to installed in order to reduce the NOx emissions significantly.     

Multi-Reservoir System Optimization using Chlorophyll-<Emphasis Type="Italic">a</Emphasis> Trophic Indexes

The problem of managing water scarcity by resorting to complex interconnected multi-source water systems needs to utilize management optimization techniques analyzing aspects of water quantity and quality in a common strategy. In the southern regions of Mediterranean Europe, the greater part of water resources for supply systems are derived from artificial reservoirs and water systems can become quite complex since they interconnect several sources and demand centers, as indeed occurs in the Region of Sardinia (Italy). A simplified approach to the requirement to insert water quality aspects in the mathematical optimization model can be achieved by examining the trophic conditions of reservoirs. Trophic State Indexes (TSI) based on Carlson’s (1977) make it possible to insert quality constraints in the water management optimization model also considering complex multi-reservoir and multi-user systems. Model formalization and implementation by the optimization toolkit WARGI (Water Resource system optimization aided by Graphical Interface) (Sechi and Zuddas 2000; Manca et al. 2004; Salis et al. 2005) is illustrated in this paper. The usefulness of a mixed quantity–quality optimization approach has been confirmed by WARGI application to a real multi-reservoir water resources system in southern Sardinia. The optimization model remains computationally efficient dealing with this complex multi-reservoir system and the obtained results can be seen as a reference target in a subsequent simulation phase.     

《湖北水电施工技术》序

<正>湖北省位于长江中游、洞庭湖北岸,在这18.59万km~2的荆楚大地上镶嵌着成千上万的河流、湖泊、湿地,蕴含着丰富的水资源,也蕴含着巨大的水能资源。新中国成立以来,湖北省的水电建设成就辉煌,先后建设了丹江口水电站、黄龙滩水电站、葛洲坝水电站、隔河岩水电站、西北口水电站、王甫洲水电站等一大批大、中、小型水电工程。尤其是近十几年来,湖北水电建设进入突飞猛进的大发展时期,相继建成了当今世界最大的混凝土重力坝和水电站——三峡水利枢纽工     

Rapid Response of a Sand‐Dominated River to Installation and Removal of a Temporary Run‐of‐the‐River Dam

Run‐of‐the‐river dams (RORDs) comprise the vast majority of dams on river systems and are commonly removed as a part of stream restoration strategies. Although these dams are routinely removed, few studies have documented the geomorphological responses of sand‐bed rivers to the removal of RORDs. We examined the response of a large sand‐bed river located in South‐Central Kansas, USA, to the installation and removal of a dam that is installed annually for seasonal recreational purposes. Channel adjustments were tracked using cross‐sections sampled over the course of 7 months as the dam was installed and subsequently removed. Multivariate spatiotemporal analysis revealed emergence of channel stability when the dam was in place for most cross‐sections, except for those immediately adjacent to or at great distances from the dam. Our results provide an approximation for how sand‐bed rivers respond to RORD construction and removal and are useful for guiding management decisions involving preservation or restoration of connectivity. Results of this study suggest that sand‐bed rivers are resilient and recover quickly when transient RORDs are removed. Copyright © 2014 John Wiley & Sons, Ltd.