共查询到19条相似文献,搜索用时 93 毫秒
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对中压开关柜中硬导体的矩形导体的选择进行了计算和分析.计算结果表明,矩形硬导体的选择以导体的载流量为依据,而导体的载流量又与导体的材质、形状、颜色、安装形式及所处的环境温度有关. 相似文献
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导体的集肤效应会影响导体的交流电阻,最终影响交流电缆的载流量,基于此,大截面导体通常采用分割导体的结构来降低交流电阻从而提高电缆的载流量。在此基础上对导体单丝表面进行绝缘处理也是降低导体交流电阻的手段之一,但IEC 60287标准中并未给出此类导体电缆的载流量计算方法。分别对220 kV电压等级导体单丝表面未处理的分割导体电缆和导体单丝表面绝缘处理过的分割导体电缆进行了空气中载流量测试,并参照IEC 60287考虑皱纹铝护套两侧空气间隙的影响,建立了220 kV电缆载流量计算方法。研究结果表明,载流量计算结果与试验结果偏差为0.74%,结果较为吻合。基于该方法对导体单丝表面处理后的分割导体的集肤效应系数进行了计算,文中所用导体单丝表面处理后分割导体的集肤效应计算所用因数ks为0.3。 相似文献
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主要介绍了分箱式GIL中管型通流导体的设计计算方法,一是根据产品设备对导体载流量的要求结合导体的电流密度来确定导体外形尺寸和壁厚的方法,二是在兼顾产品的绝缘和经济成本情况下,根据导体表面的允许场强设计基准来计算确定导体的外形尺寸的方法。 相似文献
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在TN-S系统的三相交流电路中,无论各相导体对PE导体的3n次谐波电压是否相等、无论各相导体对PE导体的分布电容的大小如何,三相相导体对PE导体的3n次谐波电压,通过它们之间的分布电容都会在PE导体上产生各自的电容电流,并且在PE导体上叠加;当三相基波电压和其他各次谐波(3n次谐波除外)电压不对称时,其各次电压的零序分量,通过相导体与PE导体之间的分布电容也会在PE导体上产生各自的电容电流。 相似文献
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针对低压大电流DC-DC高频模块电源中,为了减少绕组的高频涡流损耗,通常把厚导体分割为薄导体的并联,详细分析了把厚导体分割为薄导体的并联,由于在绝缘层处存在交变磁通,将在并联导体之间产生环流,导致导体损耗增加。有限元分析和实验结果证实了分析结果的正确性。 相似文献
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电缆导体直流电阻测量中大截面积铝芯导体直流电阻的测量一直是一个难点,本文对大截面积铝芯导体直流电阻测量方法的技术改进做了详尽的介绍.文章从测量电缆导体直流电阻原理、测量电缆导体直流电阻所使用的检测设备和环境条件要求、大截面电缆导体直流电阻测量方法的创新改进及测量过程、影响测量正确性的因素分析和测量结果及评价等几个方面进行了详细的论述.大截面积铝芯导体直流电阻测量方法的技术改进对提高大截面电缆导体尤其是铝芯导体直流电阻测量的准确性有一定的参考和指导价值. 相似文献
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A formula for calculating mutual coupling between diversely routed, horizontal earth-return conductors that measure grounding system impedance is derived by using the complex ground plane concept used to approximate the Carson equation. Each potential conductor section is approximated with equal-length segments that parallel one of the current conductor sections. By repeating the parallel segmentation of each potential conductor section with each subsequent current conductor section and summing the segment mutuals, overall mutual couplings between diversely routed conductors is obtained. This process is useful for calculating mutual to the potential conductor and for comparing possible potential conductor routings so as to minimize the overall mutual coupling 相似文献
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以碳纤维导线JRLX/T-310/40和普通钢芯铝绞线LGJ-300/40为例,比对分析碳纤维导线和普通钢芯铝绞线的载流量、弧垂和融冰特性。结果表明:在覆冰条件下,相同环境参数时的碳纤维导线和普通钢芯铝绞线的融冰特性差异可以忽略不计;当导线覆冰厚度为30 mm时,碳纤维导线的弧垂比普通钢芯铝绞线低1.4 m;在相同温度变化范围内,碳纤维导线的弧垂变化量小于普通钢芯铝绞线;当温度由80℃升至160℃时,普通钢芯铝绞线弧垂有较大的增加,而碳纤维导线的弧垂仅再增大0.161 m。这些特性表明在重覆冰条件下碳纤维导线的对地安全性要比普通钢芯铝绞线高,其在重覆冰区推广应用的优越性明显;碳纤维导线很适合在需要对线路进行增容的情况下使用。 相似文献
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为了合理选择220 kV银盘水电站送出线路重冰区导线,先从系统输送容量入手,确定输电线路导线分裂根数、间距及截面,再从重冰区输电线路设计的特点出发,通过对常见的3种钢芯铝绞线(GB/T1179—1999)的机械强度及过载能力、铝部应力、弧垂特性、耐振性能、荷载条件以及经济性等方面进行比较分析,重点分析了不同钢芯截面的导线在重冰区的技术经济特性,最终推荐银盘水电站220 kV送出线路20 mm冰区段导线选用2×LGJ-630/55,通过较为系统的导线选型分析,为重冰区高压架空输电线路导线选型、校核探讨了一套方法。 相似文献
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0.6/1kV扇形导体硅烷交联电缆成缆工艺设计 总被引:1,自引:1,他引:0
着重对0.6/1kV硅烷交联聚乙烯绝缘电缆采用扇形导体的成缆工艺进行分析和探讨,并且对硅烷交联聚乙烯绝缘电缆采用圆形导体与扇形导体的经济性进行了比较。 相似文献
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Hvidsten S. Kvande S. Ryen A. Larsen P.B. 《Dielectrics and Electrical Insulation, IEEE Transactions on》2009,16(1):155-161
The main purpose of this paper is to show the strong correlation between corrosion of the metallic aluminum conductor and the formation of interconnected cracks / voids in the conductor screen, creating initiation sites for vented water trees in service aged medium voltage XLPE cables. The results show that porous structures in the conductor screen previously reported for laboratory aged insulation systems, also develop in the conductor screen in service aged medium voltage XLPE cables. These structures can bridge the screen and serve as path for contaminants and corrosion products from the aluminum conductor and initiate water trees. A prerequisite for the formation of such structures is the presence of liquid water at the interface between the conductor and conductor screen causing corrosion. The initiation site of such structures has been identified, and is likely caused by environmental stress cracking (ESC). Initiation sites were determined in all cables, but porous structures in the conductor screen were only observed in the cable suffered from service failure, where liquid water had entered the cable conductor between the strands. Severe degradation of the XLPE insulation was observed at the initiation sites for water trees growing from these structures. 相似文献
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Transmission line engineers have sought an easy method for evaluating if external dampers are required on any new transmission line. In the past this question has been given to the damper manufacturer who has a vested interest in a affirmative answer. For single conductors (and for bundled conductors) the vibration level of a power line conductor is the result of a complicated aerodynamic process in which energy is taken into the motion from vortex action on the lee side of the conductor. The amount of energy taken in is a nonlinear function of vibration amplitude, frequency, conductor diameter, and wind speed. The amount of energy taken out is a nonlinear function of vibration amplitude, frequency, conductor mass, conductor tension, and a certain friction constant that varies from conductor to conductor. It is known that a small amount of vibration is allowed without endangering the conductor. This has been called the IEEE limit loop velocity, and is numerically equal to 200 mm/second. This paper explains a simple procedure, applicable to single conductors, which calculates a comparison of energy in vs. energy out. From this process it is shown how to select the initial tension in the conductor so that no external dampers are required 相似文献
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环境友好型输电线路用导线之二——导线的应用 总被引:1,自引:1,他引:0
叙述一种被称为"环境友好型输电线路用导线"的导线,能满足在恶劣环境条件下仍然使线路正常供电、安全运行。这种导线是一种钢芯SZ铝型线同心绞的架空导线,具有更大的导体截面利用率,能降低风载,良好的自阻尼性能和耐腐蚀、低覆冰、低电晕能力,单线不易受损,结构紧密牢靠。文中按导线的不同用途,详实的举例加以说明。它将成为未来输电线路使用中的一种重要线种。因论文篇幅较长,故分为两篇分别撰写,第一篇为导线特性,第二篇为导线的应用。 相似文献