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挂网运行的复合绝缘子若出现劣化,电气绝缘性能降低,若不及时替换将危害线路的安全运行。目前,国内外尚缺乏成熟的绝缘子运行状态检测方法,笔者在研究国内外复合绝缘子检测方法的基础上,首次引入高光谱遥感技术检测复合绝缘子的运行状态。采用高光谱成像仪对不同运行状态的硅橡胶绝缘子伞套及绝缘子串进行影像采集,成功地构建了复合绝缘子样本光谱特征库,并直观地展示了不同运行状态复合绝缘子光谱曲线及其在特征空间中的聚类特性。继而,利用特征光谱库,采用概率判决函数和贝叶斯判别规则对目标绝缘子进行状态检测,结果显示此方法可以准确地检测出绝缘子的运行状态。 相似文献
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直流输电工程与交流输变电工程不同,直流设备周围的电场为直流静电场和空间离子流场的综合场。但是,目前,国内直流输电工程的检修作业人员安全防护基本参照同等电压等级的交流输变电工程进行。当现场使用大型机具进行带电施工和检修时,由于机具的进入,作业现场的直流综合场和空间离子流分布会影响检修作业人员的安全防护效果。因此,笔者针对直流换流站的现场实际布置情况,对换流站典型施工区域有/无机具条件下的直流合成电场和离子流密度进行了测试。测试结果表明,有大型机具存在时,由于机具本体的屏蔽作用,直流合成电场和离子流密度一般较无机具时有所降低;站内各区域地面和2 m高处的直流合成电场强度均小于240 kV/m,站内各区域因空间离子流存在而引起的离子流密度小于1 000 nA/m2(除穿墙套管外的区域,离子流密度普遍低于100 nA/m2)。因此,站内机具施工人员可不采取额外安全防护措施对直流合成电场和离子流进行防护。 相似文献
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输电线路的风偏角计算所采用的都是刚体静力学模型。为了简化计算,该模型将绝缘子串和导线假设为刚体,风吹时绝缘子串不发生任何弯曲或变形。特高压线路的绝缘子串较长,风吹时其链式弯曲程度较低电压等级输电线路的绝缘子串要大,需要研究其对线路风偏角的影响。通过数值仿真计算和风偏模拟验证试验得到的结果表明,特高压线路采用棒型绝缘子可不考虑绝缘子链式弯曲的影响,但采用盘形绝缘子串,当绝缘子串两端相邻的导线悬挂点高于其自身时则需考虑,即按现有方法计算出绝缘子串的水平位移,并加上由链式弯曲引起的偏差值,否则将来可能存在特高压线路塔头部位风偏故障的隐患。 相似文献
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In a general plane-parallel electrode system the edge of the electrode will undermine the uniformity of the dielectric barrier discharge (DBD) because of the influence of the distorted electrical field. In this paper, the influence of the non-uniform electrical field on the edge effect of DBDs in a short-gap is investigated. We present some o.f the experimental results of DBDs produced by three kinds of convex-spherical electrodes. The results show that there is a dark area (the homogeneous discharge) in the central region of the electrode and a bright halo (the filamentary discharge) in the outer peripheral region, and the radius of the dark region is determined by the electrode geometry. The calculated results of the transverse (radial) field component distribution on the surface of the electrodes show that the edge effect does not come from the electrode edge, but the transverse field. The discharge has enough space to be fully developed and then format the filamentary discharge in the outer peripheral region because the streamer of the filamentary discharge is driven to move along the direction of the longer path by the transverse field. Thus, the homogeneous discharge (the Townsend DBD or a glow DBD) could not be produced in this area. 相似文献
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In a general plane-parallel electrode system,the edge of the electrode will undermine the uniformity of the dielectric barrier discharge(DBD)because of the influence of the distorted electrical field.In this paper,the influence of the non-uniform electrical field on the edge efect of DBDs in a short-gap is investigated.We present some of the experimental results of DBDs produced by three kinds of convex-spherical electrodes.The results show that there is a dark area(the homogeneous discharge)in the central region of the electrode and a bright halo(the filamentary discharge)in the outer peripheral region,and the radius of the dark region is determined by the electrode geometry.The calculated results of the transverse(radial)field component distribution on the surface of the electrodes show that the edge efect does not come from the electrode edge,but the transverse field.The discharge has enough space to be fully developed and then format the filamentary discharge in the outer peripheral region because the streamer of the filamentary discharge is driven to move along the direction of the longer path by the transverse field.Thus,the homogeneous discharge(the Townsend DBD or a glow DBD)could not be produced in this area. 相似文献
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通过比较国内外在悬垂绝缘子串风偏设计中基本风速、风压不均匀系数、风压高度变化系数等参数选取上的区别以及带来的影响,得出以下结论:在基本风速选取方面,国外无论是在风速次时换算时间段还是重现期的取值上均与我国存在较大差异;风压不均匀系数的取值及其折算方法对导线风荷载的影响显著;不同的地面粗糙度类别对风压高度变化系数的取值影响较大,我国的输电线路规范还没有对过渡区地面粗糙度类别的选取进行明确的定义.因此,还需对不同地形特征下不同高度处的风参数进行现场观测,通过积累长期的观测数据,对上述这些设计参数取值进行优化和完善. 相似文献
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