【作者】 晏松；

【导师】 梁小冰；

【作者基本信息】 广西大学 ， 高电压与绝缘技术， 2007， 硕士

【摘要】 交联聚乙烯电力电缆以其优越的电气绝缘性能得到了广泛应用，因此针对交联聚乙烯绝缘材料的特点，有必要分析其故障现象及成因。由于电力电缆多数埋于地下使用，一旦发生绝缘故障，很难较快地寻测出准确的故障位置，那么准确、迅速、经济地查找出故障点位置就很重要。本文对交联聚乙烯电力电缆故障现象进行分析并指出了新的故障成因。通过对目前国内外各种定位方法比较研究，总结得出了它们的优缺点和适用范围。基于GPS全球定位系统和行波定位理论，本文讨论分析了通过在线采集电力电缆两端行波浪涌信息的双端量故障定位方法。首先根据交联聚乙烯绝缘材料的特点选定电缆结构参数，通过分析故障情况下暂态电磁波在电力电缆中传输的波过程，推导出双端量故障定位方法的数学模型。然后使用PSCAD／EMTDC仿真工具搭建了交联聚乙烯电力电缆空载和末端短路两个试验模型，通过改变电缆结构参数和线路长度来分析各种情况下的仿真波形特点。在此基础之上，搭建了双端量故障定位试验系统模型，对金属性故障、低阻故障、高阻故障进行仿真分析。改变线路参数和故障位置可以得到不同的仿真波形，对波形进行分析可以计算出故障距离并总结出故障暂态电磁波在电缆中传输的特点和规律。对在电缆故障中占比例较大的高阻故障，重点进行比较分析。故障定位软件采用VB程序语言为开发工具，采样数据库文件采用TXT文件格式。用户可以通过简明的软件界面，调用数据文件，在计算机上实现故障距离自动计算。本文得出的结论如下：(1)验证了故障暂态电磁波在电缆中的传输速度只与绝缘材料有关，与导体半径无关；(2)故障暂态行波在电缆中衰减变形成指数规律，波形的衰减程度与线路长度成正比关系，与导体直径成反比关系；(3)与传统离线定位技术相比，双端量故障定位技术适用于各种故障类型，能够实现快速定位，定位误差小，消除了测量盲区；(4)开发的故障定位软件能够对采样数据库文件进行自动处理并给出正确的计算结果。与运用波形分析的方法人工计算得出的结果进行相互比较，能够使故障定位更准确。更多还原

【Abstract】 XLPE power cable is widespread availability because of its superiority insulationcapacity, with the focus on the characteristic of the XLPE insulation, it is necessary tostudy on the fault phenomenon and origin. Power cables are always used under theground, so it is difficult to find the fault location quickly after insulation malfunction,and so it is very important to find the fault location accurately, quickly andeconomically.Several new causes of failures are added in the XLPE power cable faultphenomenon analysis. Compared with the fault location methods home and abroad,this paper generalized merits, defects and applicability of them.Based on the global position system (GPS) and traveling-wave fault locationtheory, the method of gathering traveling-wave surge record data from both terminalsof the power cable is analyzed in this paper. Firstly, based on the characteristic of theXLPE insulation material, a two-terminal fault location mathematic model is deducedafter analysis the wave process of electromagnetic wave traveling in the power cable.After that, the electromagnetic-transient simulation software PSCAD/EMTDC isused to create two emulator models about no-load and terminal short circuit of XLPEcable. Change the parameters and length of the cable to see the alteration of theemulator wave. Based on it, create two-terminal fault location test models underthe circumstances of short circuit, low resistance, and high resistance. Differentparameters and fault points corresponding with different simulation waves, the faultlocation can be solved through analyzing them, and the characteristic and regularityof the electromagnetic wave traveling in the power cable is generalized. The paperemphatically analyzes the high resistance fault. Fault location software development is based on Visual Basic and the samplingdatabase files are stored by TXT file layout. The users can easily realize fault locationauto-calculation through concise software interface.By means of studying conclusions can been drawn as follows:1) The transfer rate of fault electromagnetic wave traveling in the power cable isrelated with insulation material not conductance radius;2) Fault transient traveling wave will reduce exponentially, the attenuation ofwave is direct ratio to the cable length and inverse ratio to the conductance radius;3) Compared with the conventional off-line positioning technology, two-terminalfault location technology can accurately locate the position for various fault types, theposition error is little, and blind area is eliminated;4) This fault location software can auto calculate these sampling data and givethe right results. Compared with the manual calculation results, fault location canbecome more accurate.更多还原