2011 Electrical Insulation Conference (EIC).最新文献_第4页

On-line condition monitoring of power transformers: A case history 电力变压器的在线状态监测:一个案例历史

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996163

A. de Pablo, W. Ferguson, A. Mudryk, D. Golovan

{"title":"On-line condition monitoring of power transformers: A case history","authors":"A. de Pablo, W. Ferguson, A. Mudryk, D. Golovan","doi":"10.1109/EIC.2011.5996163","DOIUrl":"https://doi.org/10.1109/EIC.2011.5996163","url":null,"abstract":"This paper describes how a hydrogen on-line monitor (Hydran®) accompanied with specialist help can assist Asset Managers/ Operational Managers make good decisions regarding critical plant and identify the warning signs of a potentially catastrophic failure in a large power transformers. In October 2006, a hydrogen monitor was installed in a 500 MVA, 19/230 kV step-up transformer. This monitor showed the presence of about 45 ppm of hydrogen, but readings were very stable with time. Unexpectedly, in June 2010, hydrogen readings started to increase at a very high rate in terms of milliliters per hour. Oil was sampled and dissolved gas analysis was carried out in the laboratory indicating a thermal fault type T2 (temperature between 300 °C and 700 °C) according to standard IEC 60599. For safety reasons, it was recommended to remove the transformer from service. Failure investigation showed bad connections in the conductor leads between the LV windings and the bushings. The molding of individual strands was not properly done and with time, the connection has degraded and reached high temperatures. Connections were repaired and the transformer put back in service again.","PeriodicalId":129127,"journal":{"name":"2011 Electrical Insulation Conference (EIC).","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124441090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 9

Fluorescent probes as electrical field indicators 荧光探针作为电场指示器

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996183

A. Holt, R. C. Brown, P. Lewin, A. Vaughan, P. Lang

引用次数: 1

Fiber optics temperature/vibration and moisture monitoring in power transformers 电力变压器中的光纤温度/振动和湿度监测

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996162

P. Kung, Lutang Wang, M. Comanici

{"title":"Fiber optics temperature/vibration and moisture monitoring in power transformers","authors":"P. Kung, Lutang Wang, M. Comanici","doi":"10.1109/EIC.2011.5996162","DOIUrl":"https://doi.org/10.1109/EIC.2011.5996162","url":null,"abstract":"In most aging transformers, windings failures are caused by the deterioration of the insulation, leading to arcing and short circuits. Vibrations in a transformer are generated by different forces appearing in the core and winding during the operation. Winding vibrations result from the electromagnetic forces that are generated by the interaction of the current in a winding with leakage flux. These forces are proportional to the square of the load current, and therefore vibration is always there. VibroFibre™ technology was invented to monitor the vibration of the end windings. It works according to optical interference, i.e., when subjected to vibration, the signal reflected off the sensor is interpreted as intensity changes resulting from the change in the length of a fiber Bragg grating-based cavity. However, as temperature rises, the fringes also move making it necessary for other control measures to track this temperature rise. These counter measures effectively constitute indirect temperature measurement during this vibration monitoring. The same technology is now adapted to be applied to diagnose transformers. The special sensors are based on the advanced fiber optic vibration sensing technology, where up to 50 vibration sensors can be connected in series along a single optical fiber. These sensors are made thinner so they can be embedded between the windings and are best installed by the manufacturer of the transformers. These vibration sensor arrays will generate temperature information concurrently and will work up to 250 degrees C.","PeriodicalId":129127,"journal":{"name":"2011 Electrical Insulation Conference (EIC).","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123713929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 4

Dielectric breakdown of amorphous and semicrystalline polymers 非晶和半晶聚合物的介电击穿

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996197

H. Couderc, É. David, Y. Corlu, M. Frechette, S. Savoie

引用次数: 2

Preliminary evaluation of flat glass backed mica paper tape for high voltage coil groundwall insulation using vacuum-pressure-impregnation 真空-压力浸渍高压线圈地壁绝缘用平板玻璃背云母纸带的初步评价

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996141

F. Emery, Mark F. Williams

{"title":"Preliminary evaluation of flat glass backed mica paper tape for high voltage coil groundwall insulation using vacuum-pressure-impregnation","authors":"F. Emery, Mark F. Williams","doi":"10.1109/EIC.2011.5996141","DOIUrl":"https://doi.org/10.1109/EIC.2011.5996141","url":null,"abstract":"Of interest, is to find a glass backed mica paper tape with improved dielectric properties than commercially available tapes [1]. This paper is a second on the subject and presents the results of a preliminary evaluation of flat glass backed mica paper tape. These tapes were evaluated for possible use for high voltage coil groundwall insulation using vacuum-pressure-impregnation (VPI) with epoxy resins. Flat Glass Mica Paper tape was used to insulate aluminum test bars and impregnated using a VPI process using epoxy resin. The impregnating resin and process is used in the fabrication and processing of high voltage stator coils usually insulated with glass backed mica paper tape. An evaluation of the insulated test bars was done and the results are compared to other commercially available glass backed mica paper taped test bars; processed and evaluated under identical conditions. The flat glass mica paper tape was used to make up insulated full size stator coils which in turn were subject to electrical, chemical, and mechanical testing. This paper reviews the results of the evaluation of the flat glass mica paper tape; showing good dielectric properties that make it suitable for use in high voltage coil insulation.","PeriodicalId":129127,"journal":{"name":"2011 Electrical Insulation Conference (EIC).","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122117073","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Characteristics of noise and interphasal PD pulses in operating stator windings 工作定子绕组中噪声和相间PD脉冲的特性

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996106

G. Stone, S. Campbell, H. Sedding

引用次数: 12

Practical consideration of mechanical measurements in cable diagnostics 电缆诊断中机械测量的实际考虑

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996178

Z. A. Tamus

引用次数: 13

Life cycle testing of nanomaterial-modified liquid electrical insulations 纳米材料改性液体电绝缘体的寿命周期试验

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996208

M. Winkeler, R. Goetter

引用次数: 1

Global monitoring approach in a large autotransformer through PD, DDF and DGA analysis: PD source location and maintenance action planning 通过 PD、DDF 和 DGA 分析，对大型自耦变压器进行全局监测：PD 源定位和维护行动规划

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996147

M. Tozzi, A. Cavallini, G. Montanari, V. Iuliani, C. Serafino

{"title":"Global monitoring approach in a large autotransformer through PD, DDF and DGA analysis: PD source location and maintenance action planning","authors":"M. Tozzi, A. Cavallini, G. Montanari, V. Iuliani, C. Serafino","doi":"10.1109/EIC.2011.5996147","DOIUrl":"https://doi.org/10.1109/EIC.2011.5996147","url":null,"abstract":"Feasibility and effectiveness of a Global Monitoring approach on a 250 MVA autotransformer are illustrated in this paper. The on-line Global Monitoring System (GMS) is constituted by a Partial Discharge Monitoring (PDM) system, a bushings Dielectric Dissipation Factor Monitoring (DDFM) system and a Dissolved Gas Analysis (DGA) on-line monitoring unit. Combining the results obtained from the three systems, it was possible to detect, identify and locate two different PD sources producing a critical level of hydrogen. The first PD activity, ascribable to presence of gas bubbles in the oil, disappeared after oil treatment. The second one, due to wrong constructional arrangement at the winding connections to the bushings, did not extinguish after the oil treatment and started again to produce a large and critical amount of hydrogen. The trend of the PD activity was analyzed for six months, resorting to statistical indexes, such as the amplitude and repetition rate, in order to help the maintenance manager to plan proper actions. This successful example highlights how predictive monitoring systems can reduce the maintenance costs in critical assets as large power transformers, stressing the importance of analyzing various diagnostics marker together in a global monitoring approach [1–3].","PeriodicalId":129127,"journal":{"name":"2011 Electrical Insulation Conference (EIC).","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131005061","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 3

Root cause investigation of the inadvertent failure of unit 2 forced draft fan motor and the corrective actions implemented 2号机组强制风机电机意外故障的根本原因调查及纠正措施的实施

2011 Electrical Insulation Conference (EIC). Pub Date : 2011-06-05 DOI: 10.1109/EIC.2011.5996144

J. K. Amoo-Otoo

{"title":"Root cause investigation of the inadvertent failure of unit 2 forced draft fan motor and the corrective actions implemented","authors":"J. K. Amoo-Otoo","doi":"10.1109/EIC.2011.5996144","DOIUrl":"https://doi.org/10.1109/EIC.2011.5996144","url":null,"abstract":"In today's competitive power generation market place, reliability and availability of auxiliary motors is critical to the operation of the power plant. Thermal degradation of the winding insulation of high voltage motors has prompted us to consider ways to monitor the condition of the insulation of the winding of our 4160V critical motors. This is because the forced draft fan motor 2B inadvertently failed due to the destruction of a section of both the winding and the laminated core of the motor which set the motor into flames. The machine environment creates several mechanisms that can age the stator insulation. In addition to electrical and mechanical stresses, heating of the insulation due to copper losses in the conductor is an important thermal aging factor, especially in conjunction with differential expansion forces experienced by conductor and insulation, leading to a progressive degradation of the electrical insulation. Many insulation failures originate with aging that occurs over many years. To operate cost effectively, means to periodically assess the condition of insulation of the winding are needed. This paper provides the root cause analysis of the inadvertent failure of Unit 2B Forced Draft Fan Motor and the steps taken to correct the failure and the implementation of the corrective actions. The analysis also showed that out of the six potential causes, three of them are the most likely causes and they are thermal aging, operator's failure to heed to the manufacturer's hot start and cold start timing sequence and excessive heat due to poor maintenance work on cleaning and changing the filters.","PeriodicalId":129127,"journal":{"name":"2011 Electrical Insulation Conference (EIC).","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2011-06-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130202362","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0