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通过对35 kV单芯电缆金属屏蔽层感应电压的理论计算与现场实测,提出了大型企业35 kV单芯电缆金属屏蔽层接地方式,结合现场运行经验提出了应对单芯电缆金属屏蔽层发生多点接地的措施。 相似文献
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从单芯电缆的结构原理入手,介绍了单芯电缆在使用时若没有相应的单芯电缆护层保护措施,可能出现的各种安全事故隐患。分析了电缆护层保护器对单芯电缆的保护原理及电缆护层保护器应用于高压电缆馈电开关设备时应注意的各种问题,并提出其一次系统接线图的正确接法。为高压开关设备制造企业在解决此问题时提供一定帮助。 相似文献
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本文对石化厂供电网的35kV单芯钢丝铠装电缆故障进行了分析,对损坏原因进行了探讨,提出了单芯钢丝铠装电缆应用中的注意事项。 相似文献
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简要介绍了单芯电缆金属护层接地的各种方式,对BATA电网20 kV单芯电缆金属护层接地方式进行了简单分析并进行了接地设计,包括单芯电缆金属护层感应电压计算。BATA市位于赤道几内亚共和国大陆(木尼河地区)西北部,西临大西洋,市区面积约95 km2。BATA原有配电电网相当薄弱,在2010年后该市电网进行了大面积的改建及新建。经改造升级后,该市中压配电网电压等级为20 kV,配电线路均采用单芯电缆线路。 相似文献
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随着大面积电缆的广泛应用,解决单芯电缆感应电压问题,成为工程设计中的重要问题。文章通过实际计算分析了市南地区35kV630mm^2截面单芯电缆感应电压的处理方法。 相似文献
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高压单芯电缆金属护套感应电压计算及其保护方式 总被引:5,自引:0,他引:5
对高压单芯电缆在运行时护套产生的感应电动势进行了计算,为确保电缆的安全运行采取了护套的一端接地与交叉换位方式,降低了高压单芯电缆护套感应电动势,效果良好。 相似文献
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近年来,35 kV单芯电力电缆以其载流量大、弯曲半径小、敷设路径灵活等优点得到了广泛应用,也给电力电缆的运维管理带来了很多新的问题和挑战.高压单芯电力电缆金属护层(金属屏蔽层)接地方式不规范或接地缺陷会使单芯电缆金属护层上感应出较高的电位,烧坏过电压保护器,或者产生较大的环流,导致金属护层持续发热,烧损、引燃电缆外护套... 相似文献
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Determination of the reduction factor for feeding cable lines consisting of three single-core cables
The paper presents an original analytical procedure for the determination of the ground fault current distribution in the cases when a feeding line is composed of three single-core cables. The procedure takes into account the existence of all three cable sheaths as the return path for the ground-fault current. The reduction factor for these types of cables as given by the cable manufacturer takes into consideration only the existence of the metal sheath of a faulted single-core cable. As a consequence of that, the estimations of the safety conditions (step and touch voltages) on the grounding systems of the supplied stations are too severe. For the high-voltage cables, a certain, sufficiently low reduction factor achieved by an increase of the sheath cross-section can be demanded from the manufacturer. In both cases, too conservative values for the reduction factor lead to unnecessary expenditures. The quantitative analysis performed in this paper shows that the reduction factor for three single-core cables belonging to the same line is significantly lower in comparison to the situation when each of these cables is treated separately. 相似文献
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目前城市电网中35kV以上电压等级的电缆线路越来越多,35 kV以上电压等级线路往往使用单芯电缆。单芯电力电缆线芯通过交变电流时,金属护套上会产生感应电势。为了防止感应电压过大对人体造成伤害,需要将金属护套两端牢固接地。当电缆金属护套两端接地时金属护套中会有环流通过,护套环流过大时会严重影响电缆的安全运行。通过MATLAB及LabVIEW软件编程方法实现了计算一至四回路任意排列电缆线路的护套环流,利用环流计算软件提出抑制环流措施和电缆优化敷设方式,为未来电缆敷设提供科学指导意见。 相似文献
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高压电缆缓冲层的设计与工艺研究 总被引:1,自引:0,他引:1
高压与超高压交联电缆金属护套与电缆缆芯之间的缓冲层是电缆的重要组成部分,对电缆的机械、热性能具有重要的影响。为研究缓冲层对电缆性能的影响,分析了不同的阻水带的热阻特性与工艺特点,对国产两种同型号不同厂家的电缆进行了对比温升试验,最后讨论和分析了现在国内外高压交联电缆缓冲层的结构与工艺特点。研究表明,具有不同结构与材料的缓冲层,对电缆本体的热阻有显著影响,也对电缆载流量有着很大的影响。在此基础上,对国产电缆的缓冲层设计与工艺提出了一些建议。 相似文献
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Cable installations for three-phase systems consisting of parallel single-core cable circuits carry different currents due to inductive coupling. Supplementary installed additional conductors grounded on both ends show several beneficial effects: balanced outer conductor currents, improved throughput load, and reduced current-dependent losses. With cables laid in free air, additional conductors are especially economical 相似文献
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Proximity effect and eddy current losses in insulated cables 总被引:1,自引:0,他引:1
Insulated cables are generally designed according to thermal criteria: the current rating depends on the permissible temperature inside the insulation. As the heating of a cable mainly results from Joule losses, it is worthy to determine the current distribution in its metallic components (the core and the metallic screen for single core cables). The current distribution in tables is affected by the skin effect and the proximity effect due to neighbouring cables of the circuit itself or from parallel links. A general method is developed to calculate the current distribution in the core and the screen of a single-core cable, starting from Maxwell equations. The stress is set upon skin and proximity effects, taking into account the influence of the frequency. Joule losses are calculated in some practical cases of three-phase links 相似文献