共查询到19条相似文献,搜索用时 187 毫秒
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交联聚乙烯电缆耐压试验方法 总被引:1,自引:1,他引:1
论述了变频谐振系统进行高压电力电缆谐振耐压试验的基本原理。通过采用变频谐振系统在工程实践中的应用,论证了变频谐振方法在交联聚乙烯电缆现场交流耐压中的效果和可行性,并指出了交联聚乙烯电缆直流耐压试验的缺点。 相似文献
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分析了变频谐振系统进行高压电力电缆谐振耐压试验的特点和基本原理,通过工程实例,论证了变频谐振方法在交联电缆现场交流耐压试验中的可行性。 相似文献
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通过对高压交联聚乙烯绝缘电缆进行直流耐压、0.1Hz超低频耐压、工频谐振以及调频串联谐振耐压等试验方法的分析比较,指出直流耐压对交联聚乙烯电缆的危害;超低频试验能有效发现电缆的水树故障;串联谐振的等效性最好;调频揩振试验方法等效性较好,设备轻便,试品长度的范围几乎不受限制。针对高压交联聚乙烯绝缘电缆耐压试验方法提出了建议。 相似文献
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油浸纸绝缘电力电缆端工试验和预防性试验广泛使用直流耐压,但目前交联聚乙烯电缆在很多地方已几乎已代替了油浸纸绝缘电缆。交联聚乙烯绝缘在直流电压作用下,空间电荷效应严重,直流耐压试验危害交联聚乙烯电缆绝缘的介电强度和寿命,因此人们不得不寻找其他耐试验的手段,其中0.1Hz耐压试验是主要的方法之一,为此,介绍了目前国内外0.1Hz高压发生器的简单工作原理和性能指标。 相似文献
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本文讨论了对交联聚乙烯电缆电缆现场耐压试验的各种试验方法并得出以下结论:直流耐压试验对交联聚乙烯电缆不仅是无效的而且是有害的,对于等电压等级的交联聚乙烯电缆,采用0.1Hz正弦交流耐压并结合tgδ的测量,可以有效的发现绝缘的缺陷并对其进行老化评估;对于64/110kV及以上电压等级的交联聚乙烯电缆,采用变频谐振电源进行耐压试验是现场唯一可行的方法。 相似文献
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超低频与变频谐振电压测试是电力电缆绝缘状态检测的有效方法.对不同类型的电缆缺陷检测方法进行了综合比较,给定了不同检测手段的优缺点及适用环境.针对超低频与变频谐振测试,通过设计电缆缺陷试品与搭建现场仿真测试平台,比较了两种方法对电缆相同缺陷的检测性能.试验结果表明,超低频测试与变频谐振测试均可实现对局部放电的有效检测,但是超低频检测在介损测量试验中的表现并不理想. 相似文献
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指出了高压橡塑电缆传统直流耐压试验的弊端,根据国内外试验标准和技术的发展,分析比较了超低频(0.1 Hz)法、工频谐振法及变频谐振法等耐压方法的特点,并结合大连电网的实践经验,提出了高压橡塑电缆耐压试验应遵循的原则和采用的方法。 相似文献
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Given M.J. Fouracre R.A. MacGregor S.J. Judd M. Banford H.M. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2001,8(6):917-920
Considerable effort has gone into developing polymer formulations and cable designs to minimize failures through water tree growth. However, diagnostic techniques still are required to enable the estimation of the level of damage present within a service cable. This paper reports on progress regarding the application of dielectric spectroscopy to cable diagnostics. A 40 kV, crosslinked polyethylene (XLPE) insulated coaxial cable was used as a model power cable. Sample lengths were immersed in a potassium chloride solution and some of these were subjected to AC electrical stress. After an 8 week duration, a high density of tress was found in the electrically stressed cable. Dielectric spectra have been measured for both sample types in the frequency range of 10-5 to 105 Hz. Insertion loss measurements were also carried out in the frequency range of 3×10 5 to 3×109 Hz. From both types of measurement, it was possible to distinguish between the cables containing water trees and those that were free from water tree structures. These approaches could therefore be developed in order to provide diagnostics for the detection of water tree damage in electrical power cables 相似文献
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介绍一种额定电压66 kV抗水树XLPE绝缘轻型海底电缆的研制方法。通过对模型电缆进行工频电压和雷电冲击电压击穿性能测试,按照CIGRE TB 722:2018规范对研制样品进行500 Hz/3000 h、50 Hz/8750 h、50 Hz/17500 h 3种湿式绝缘质量鉴定试验,按照CIGRE TB 490:2012和CIGRE TB 623:2015规范对研制产品进行型式试验,试验结果完全满足设计规范要求。在未来的深远海、大功率海上风机互联阵列海缆选型中,66 kV抗水树XLPE绝缘轻型海底电缆可以完美替代35 kV XLPE绝缘海底电缆。 相似文献
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0.1 Hz超低频余弦方波耐压系统,由于与工频耐压系统有良好的等效性且具备体积小,重量轻,能有效的检测出交联聚乙烯电力电缆(简称XLPE电力电缆)的绝缘缺陷等优点,在XLPE电力电缆耐压试验的应用越来越多。但现有超低频设备的极性转换电路设计有二阶阻尼震荡,造成能量损失,使得极性转换后正负电压不一致;由于XLPE电缆的特殊空间结构,这样会增加XLPE电力电缆的空间电荷积累量,最终对电缆造成隐性伤害。针对以上问题,提出了采用反向可馈电的极性转换电路的设计方法来解决此问题。通过Matlab/Simulink仿真表明:此方法能够补充极性转换过程的能量损失,使得极性转换后正负电压一致;仿真结果与理论分析一致,验证了设计的正确性。 相似文献
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Performance of reduced wall EPR insulated medium voltage powercables. II. Mechanical characteristics
For the replacement of paper-insulated lead covered power cables (PILC), reduced insulation wall designs have been developed. They provide a reliable lower diameter cable design for installation in existing PILC conduits. This paper presents the results of mechanical tests conducted on both reduced- and full-wall EPR insulated power cables. Both jacketed and nonjacketed cable designs have been subjected to mechanical pulling forces which greatly exceed recommended industry limitations, followed by electrical testing to ascertain cable performance. The results of this study conclude that reduced-wall EPR insulated cables can safely withstand the same pulling forces as recommended for conventional walls and can be designed for installation under the same pulling limitations 相似文献
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高压XLPE电缆绝缘V t特性研究综述 总被引:2,自引:0,他引:2
交联聚乙烯(cross linked polyethylene,XLPE)绝缘电力电缆是输电线路的重要电
力设备。针对高压交流和直流电缆系统的运行现状,介绍了运用V t特性(击穿电压与击穿时间的关系)曲线描述XLPE电缆绝缘的电老化寿命模型,分析了国内外高压交、直流XLPE电缆绝缘V t特性的研究方法及相关结果。已有的研究结果表明,交流XLPE电缆绝缘的电老化寿命指数n值在9~25之间,直流XLPE电缆绝缘的电老化寿命指数n值在13~20之间。国内目前尚未见有关直流电缆绝缘V t特性研究的文献报道。 相似文献
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This paper provides information on the aging of URD power cable insulated with a tree-retardant crosslinked polyethylene (TR-XLPE) compound, installed in a typical utility environment, Numerous evaluations were performed on samples of power cables aged up to 7 years in-service. AC and impulse voltage breakdown data are compared with data for similar 35 kV ethylene propylene rubber (EPR) and crosslinked polyethylene (XLPE) insulated cables removed from the same utility system. The data show that, to date, the rate of degradation of TR-XLPE cables is less than that of the EPR and XLPE insulated cables. Extrapolation of the data, assuming the same rate, indicates TR-XLPE cable will have the longest life 相似文献