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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。 相似文献
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<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。 相似文献
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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 相似文献
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110kV充油电缆油样介质损耗超标的处理 总被引:1,自引:0,他引:1
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 相似文献
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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. 相似文献
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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. 相似文献
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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. 相似文献
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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。 相似文献
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Abdolall K. Buchholz V.L. Cartlidge D.M. Morton C.P. Armanini G.B. Harris A. Valli G.F. 《Power Delivery, IEEE Transactions on》2002,17(2):302-307
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 相似文献
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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。 相似文献
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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. 相似文献
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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 相似文献
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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。 相似文献