150kV铝芯充油电缆的研制

充油电缆最重要的性能指标是电缆的介质损耗,而电缆的介质损耗与电缆油密切相关。查阅相关的产品标准,除IEC等标准对充油电缆铝导体的直流电阻有规定外,我国的国家标准及其它一些国家标准仅规定了铜芯充油电缆。铝芯充油电缆的生产难点在于,铝单线拉制过程中沉积在单线表面的铝大拉油及导体生产过程中产生的铝灰,将通过充油电缆油道对电缆油产生污染,从而影响电缆的介质损耗。我公司通过不断摸索,在包括铝单线拉制、退火、铝单线清洗、中空铝导体绞制等方面采取了大量的措施后,研制出的铝芯充油电缆,电缆油的介质损耗角正切tgδ为0.000 4,电缆的tgδ为0.002 2,与我公司生产的铜芯充油电缆相当。     

充油电缆火灾事故的调查及分析

<正> 我国充油电缆投运已有二十余年历史,迄今已有数百公里110～330千伏充油电缆在全国各发电厂、变电所和输电线路上运行,500千伏充油电缆正在试运行。充油电缆采用可燃性的油和纸作为绝缘介质,防火是一个重要的问题。由于充油电缆敷设的廊道或竖井通常具有一定的自然抽风作用,有时为了改善电缆散热条件还装置     

充油电缆铅层补漏方法

文化大革命以来,在各地水电站和跨江电网连结线上已广泛使用了国产110～330千伏充油电缆。由于充油电缆铅层机械强度低,故常常因各种原因造成裂口,使电缆油向外溢出。充油电缆发生铅包漏油后会导致电缆系统内电缆油减压、失压,甚至进气和酿成电击穿事故。因此,铅层漏油是充油电缆线路运行中一个突出的问题。国外,日本东京电     

上海电缆研究所1981年第二批已鉴定成果简介

<正> 1.充油电缆绝缘工频长期击穿试验研究本研究通过对充油电缆绝缘模拟样品在不同温度梯度、不同绝缘油浸渍绝缘的恒定梯度以及逐级击穿的条件下进行试验,得出如下结论: (1)充油电缆绝缘的长期工频击穿性能符合韦伯尔统计规律,从而有可能运用统计方法进行充油电缆设计及估计充油电缆绝缘运行的可靠性与寿命。     

充油电缆在线监测系统建设及运用

介绍了鲁布革水力发电厂220kV充油电缆在线监测系统的组成和特点,说明了监测充油电缆相关参数的意义;展示了充油电缆屏蔽层绝缘电阻、泄漏电流、油温油压及电缆表面温度的测量情况,另外阐述了系统在建设、使用过程中的注意事项。     

阻燃充油电缆的研制进展

一、前言自容式充油电缆电气性能优良,适合于在水电站内布置,又可作高落差敷设。所以,在大型的水电站中往往采用自容式充油电缆作为高压引出线。但自容式充油电缆的浸渍剂(合成油或矿物油)容易燃烧,若处理不当或在故障时易引起火灾。如美国的大古力第三发电厂因充油电缆而引起火灾,造成损失极大。为此,国外正在进行阻燃充油电缆的研究开发,以     

500 kV充油电缆局部放电在线监测系统的研究

根据某水电厂500 kV充油电缆的运行方式,提出了500 kV充油电缆局部放电在线监测系统的整体方案,研制了整个在线监测系统的硬件和软件,开发了500 kV充油电缆局部放电在线监测系统,已投运于该水电厂A厂AB联络线500 kV充油电缆出线端终端的在线监测。监测结果表明,该系统不但可以准确计算、显示7个放电参量,并且可以显示4种放电谱图,能有效地判断绝缘的放电状态。     

110kV充油电缆油样介质损耗超标的处理

由于 110 k V充油电缆的油样达不到“电力设备运行预防性试验”标准的要求 ,该电缆不能投入系统的运行。本文介绍了如何采用合格的充油电缆的电缆油来置换原有的劣化电缆油 ,使油样的耐电压、介质损耗等技术指标得到了改善 ,并投入了运行 ,为本公司有效地降低处理成本约 16 .5万元     

500kV充油海底电缆过负荷能力分析

当海底电缆发生故障时,在进行运维检修前,往往需要在一定时间内进行过载.海底运行环境较为复杂,海底电缆在不同的敷设环境下,其过负荷能力也不相同,有必要对具体敷设环境下海底电缆过负荷能力进行具体分析.本文以海南联网系统500 kV充油海底电缆作为研究对象,构建了500 kV充油海底电缆暂态热路模型,实现了对不同敷设环境下的应急电流和应急时间计算与分析,给出了不同敷设环境下海底电缆过负荷能力的规律,进行了我国首次500 kV充油海底电缆加热实验,实验结果证明了本文建立的充油电缆过负荷分析模型及方法的有效性.本文给出的500 kV充油海底电缆的过负荷能力分析方法及结论,可为运行部门提供过负荷能力评估以及电力调度依据.     

第四部分 高压电缆

(一)国外高压电力电缆概况到目前为止,世界上正式投入运行的500千伏级的超高压电缆,是1957年法国里昂电缆厂制造的一根强迫油冷自容式充油电缆,敷设在瑞典。继此,日本的古河、住友、日立、昭和四家公司,在1959年也曾分别试制了500千伏自容式充油电缆样品。1970年,以东京电力公司为中心,各制造厂又分别制造了500千伏自容式充油电缆和钢管电缆,正在进行三     

高温超导输电电缆的发展现状

高温超导(HTS)电缆具有低损耗、大容量、无污染等优点,是智能电网基础技术之一,已在电力系统中已受到越来越多的关注.笔者介绍了HTS电缆的结构、特点及性能优势,阐述了HTS电缆在国内外的研发概况,指出了HTS电缆的未来重点应用领域.在此基础上,指出了HTS电缆在智能电网中应用尚需解决的技术性、经济性及工程适用性等方面的...     

高性能低烟无卤阻燃聚乙烯电缆料的浅析

随着社会的不断进步,科技的不断发展,人们的环保意识日益增强,对用于电线电缆制造的低能耗、低污染材料的研究日益兴起.主要对低烟无卤阻燃电缆料作一些简要分析,并介绍了其优缺点,旨在对其研究和应用有所帮助.     

Engineering a solution to the aging of HV self-supporting cables by dry-band arcing

The retrofit rod of controlled resistivity clearly has the potential to remove the threat of dry-band arc damage on all-dielectric, self-supporting (ADSS) cables. This is achieved by reducing the maximum current available on the cable for arcing activity. Rods can be applied to polyethylene sheathed cables or arc-resistant sheathed cables and can improve the performance of both. Extensive trials in the UK have shown that the rod works and have confirmed predictions of computer models. However, the engineering of the application of such as solution is complex. Individual spans of different geometry, including cable sag, must be considered. In particular, local variation in pollution is critical; so knowledge of the proximity of the sea or industry must be considered. It is also very likely areas that do not experience much rainfall will be particularly onerous because the cable will not be naturally washed regularly, so the pollution on its surface will tend to build up, reducing its resistance in times of high humidity, fog, and dew.     

新型电缆的低烟无卤阻燃环保特性

发生火灾时,工程中使用的优质阻燃电缆可以减少火灾中人员的伤亡和经济的损失,因此设计师和业主都非常关注电缆的低烟无卤阻燃性能。介绍了电缆的种类,对新型铝合金铠装电缆的低烟无卤阻燃性能作了详细的阐述。经检测,该新型电缆已通过测试,值得推广。     

高压电缆绕组直线电机定子及绕组的涡流分析

为研究高压电缆绕组直线电机运行中可能出现的发热现象,建立了直线电机定子及绕组电缆的计算模型,用有限元法计算了电机在三相交流电作用下的涡流及电磁损耗分布,研究了绕组电缆有无金属屏蔽时电机内涡流分布的变化,并分析了涡流产生的热效应及其对电机运行带来的影响。研究表明,若定子绕组电缆有铜屏蔽层,运行时屏蔽层内将感应很大的涡流,其热效应可使电缆绕组烧损,进而严重影响高压电机的正常运行。研究结果可供高压直线电机定子绕组电缆的结构设计及选型参考。     

BC Hydro 15 kV cable explosion

This investigation was prompted by a cable fault explosion inside a cable duct which housed a BC Hydro 15 kV underground standby feeder cable. The incident occurred in September 1998 at a housing complex in Vancouver, BC, Canada. Damage to the building vault was extensive and could very easily have resulted in severe injury or a fatality had anyone been in the immediate area of the vault. A failure analysis investigation revealed that the cause of the explosion was an accumulation of combustible gases which were decomposition products of the polymeric cable components which were liberated from the cable by a long duration high impedance fault. Several unusual circumstances had to occur concurrently to allow the explosive condition to develop. The events that led to the explosion are discussed in terms of the failure mechanism of the cable and the effects of reclosure arcing     

新型环保复合材料电缆桥架

针对目前电缆桥架存在的通用问题,研制了一种G/FQ防火环保型多元复合材料电缆桥架。对其特点、性能指标作了详细介绍,并分析了与同类电缆桥架产品相比具有的优势。使用证明,该产品节能环保,具有较高的强度、防火性、韧性、耐化学性。     

Assessment of station cable condition using wireless telemetry and diagnostic tests

Following the premature in-service failure of a 15 kV, XLPE insulated cable in a hydraulic generating station, a program was devised to: determine the root cause of failure; assess the condition of the remaining cables in the station; and ensure that the field modifications proposed to rectify the problem were effective. The underlying mechanism driving the failure was found to be overheating of the cable sheath as a result of the inadvertent formation of ground loops in the cable support structure, and hence circulating currents. Physicochemical tests of cable sections recovered from the failed circuit showed that the cable had experienced temperatures in excess of 115 /spl deg/C. Electrical diagnostic testing of the affected cable circuits indicated that the majority of the cable length was unaffected by the overheating. However, the portion of the cable within the switchgear cubicle may have undergone some ageing as evidenced by higher dielectric loss values. On-line temperature measurements, including those on the current-carrying components using wireless telemetry, confirmed that one of the sources of the high temperatures was the ground structure in the cubicle.     

Algorithm to predict dry-band arcing in fiber-optic cables

Utilities frequently use ADSS (all dielectric self-supporting) fiber-optic cables installed on transmission lines 3-6 m below the high voltage conductors. Dry-band arcing occurs on the fiber-optic cables when the cables are polluted and wet. This has been assumed to cause cable failures. An equivalent circuit has been developed to represent the polluted fiber-optic cable in the high voltage environment. The objective of this paper is to present a novel numerical method that can be used to predict dry-band arcing in fiber-optic cables. KCL (Kirchoff's current law) is used to derive node point equations for the equivalent circuit. Forward elimination and backward substitution of node voltage is used to solve the equations. The effect of pollution, tower arrangement, and conductor sag is analyzed. The numerical method has speed advantages over circuit simulation methods. This method includes conductor sag, nonuniform pollution, and variable capacitance. This algorithm can be used to predict dry band arcing in fiber-optic cables     

环保型电力电缆塑料保护管的研制

随着城市电力电缆入地改造工程的不断推进,防止地下水重金属污染问题已成为环境关注重点,具有环保性能的电力电缆塑料保护管的研制开发尤显迫切。文章就环保型电力电缆塑料保护管的定义与技术要求;产品配方、生产工艺、成型设备等诸环节如何确保环保标准要求以及相关检验项目、性能参数作了说明。该产品已达到国际同类产品先进水平。