高压XLPE电缆料的储存期对其基本参数影响的研究

对高压ＸＬＰＥ电缆料的基本参数如：反应动力学参数，动态力学性能，流变性能等进行研究，并分析了储存期对电缆料的基本参数影响，为考察电缆料的质量稳定性，优化交联工艺，提供理论依据。     

0.1Hz超低频耐压试验装置的设计及实现

分析了用直流电压对ＸＬＰＥ／ＰＥ电缆进行耐压实验存在的问题,介绍了ＸＬＰＥ／ＰＥ电缆０．１Ｈｚ超低频耐压试验装置的设计及实现方法。     

长距离地下传输用500k VXLPE电缆及附件的研制第一部分电缆绝缘设计

介绍了研制５００ｋＶＸＬＰＥ电缆的基础研究成果。研究结果认为，决定当今ＸＬＰＥ电缆性能的因素是绝缘中的杂质和半导电层的凸起，ＸＬＰＥ电缆的绝缘性能取决于这些缺陷的大小。通过ＸＬＰＥ电缆样品试验，确定了电缆的最小绝缘击穿场强，以确定５００ｋＶＸＬＰＥ电缆的设计参数。结果发现，取绝缘厚度为２５ｍｍ是可能的。     

城网110kV XLPE电缆T接头的实施

城网１１０ｋＶ　ＸＬＰＥ电缆Ｔ接头的实施广州供电局电缆管理所蔡兴波ＸＬＰＥＣａｂｌｅＴＪｏｉｎｔｓｉｎＵｒｂａｎ１１０ｋＶＮｅｔｗｏｒｋ￥／／近１０年来，我国电力工业建设已向高电压、大容量和密集型的方向发展，许多大中城市也都在同步进行城网改造。其中采...     

用超低频方法进行XLPE／PE电缆试验

概括介绍了国内外在ＸＬＰＥ／ＰＥ电缆上进行０．１Ｈｚ超低频试验的研究成果,指出用直流电压对ＸＬＰＥ／ＰＥ电缆进行耐试验是不合适和不安全的,主要表现在直流电压对发现ＸＬＰＥ／ＰＥ电缆绝缘缺陷的不灵敏和过高的直流电场对电缆带来的不必要的进一步的损伤。     

用超低频方法进行XLPE/PE电缆试验

概括介绍了国内外在ＸＬＰＥ／ＰＥ 电缆上进行０ ．１ Ｈｚ 超低频（ＶＬＦ） 试验的研究成果,指出用直流电压对ＸＬＰＥ／ＰＥ 电缆进行耐压试验是不合适和不安全的,主要表现在直流电压对发现ＸＬＰＥ／ＰＥ电缆绝缘缺陷的不灵敏和过高的直流电场对电缆带来的不必要的进一步的损伤。介绍了哈尔滨理工大学和哈尔滨电业局合作研制的０ ．１ Ｈｚ 超低频高压试验系统。     

电力电缆施工与技术

电力电缆施工与技术青岛电业局送变电工程公司黄绪杰目前，超大型截面电力电缆施工与技术是我国电力网建设的主要研究课题之一、南京路变电站南东甲乙线路敷设的电力电缆是引进德国具有９０年代先进水平的ＸＬＰＥ１×６３０ｍｍ２ＲＭ／３５ｋＶ电力电缆。该电缆结构合理...     

110kV交联聚乙烯电缆的交流耐压试验

１１０ｋＶ交联聚乙烯电缆的交流耐压试验石家庄电业局梁少山，齐振铎，黄普立１交联聚乙稀（ＸＬＰＥ）电缆进行交流耐压试验的必要性国内外的大量研究资料表明，适用于油浸纸绝缘电缆的直流耐压试验，对于ＸＬＰＥ电缆则不宜使用。国外一些电缆制造厂明确反对ＸＬＰＥ电...     

锂离子电池新型正极材料——二氧化锰纳米纤维嵌锂行为的研究

采用ＴＥＭ、ＸＲＤ分析等方法对新型二氧化锰纳米纤维电极材料进行表征,ＴＥＭ观测结果显示这种锰材料是由许多二氧化锰纳米纤维缠绕成巢状,其纤维直径约为１ｎｍ～１０ｎｍ之间;从ＸＲＤ分析表明,它是一种复合结构的锰氧化物,以钡镁锰矿为主体结构,并含有其他钠水锰矿及水羟锰矿结构。从样品电极在１ｍｏｌ／ＬＬｉＣｌＯ４的ＰＣ－ＤＭＥ（１∶１）溶剂中的循环伏安曲线,可以看出在扫描的电压范围内,在３．８Ｖ和２．８Ｖ附近出现一对可逆对称的氧化还原峰,它对应于二氧化锰纳米纤维电极中锂离子的脱出－嵌入反应。通过二氧化锰纳米纤维电极在不同电流密度下的放电,可以看出该电极采用小电流放电（０．２４ｍＡ／ｃｍ２）,其容量可达到约１９０ｍＡｈ／ｇ,而且具有３Ｖ的放电平台;而在较大的电流密度（０．９６ｍＡ／ｃｍ２）放电仍具有约１５０ｍＡｈ／ｇ的放电容量。可见,该电极具有良好的负荷特性和较高的放电容量。     

XLPE电力电缆过负荷温升与早期损坏机理的研究

分析讨论了ＸＬＰＥ介质的热稳定性能，及其随温度升高变化的规律，水树枝引发速率与发展速率的变化规律，着重研究了ＸＬＰＥ电力电缆负荷温升与早期损坏机理，发现温度升高到１３７℃以上时，ＸＬＰＥ电力电缆绝缘介质将发生电热击穿，此时，水树枝大量引发与迅速发展，水分，杂质和氧气与介质的化学反应以及气隙的局部放电造成介质的局部老化就是ＸＬＰＥ电力电缆早期损坏的重要原因。     

交联聚乙烯电缆绝缘交联度径向非均匀性探讨

在交联聚乙烯电缆交联度测试中,热延伸法测量表明,高压交联电缆绝缘内层的延伸率大于外层,说明绝缘内层的交联度小于外层,但凝胶含量试验方法的测试结果却与热延伸试验的结果完全相反,通过分析认为是内、外层绝缘结晶形态和结晶度的不同导致了凝胶含量试验法测试交联度的不准确性;此外,通过物理机械性能试验,发现绝缘内层的抗拉强度和伸长率小于外层,这些结果说明电缆绝缘交联度存在径向的非均匀性。     

Thermoluminescence in XLPE cable insulation

Crosslinked polyethylene (XLPE) has been employed in underground transmission and distribution cables because of its excellent electrical and mechanical properties, such as low permittivity and dielectric loss, high degree of toughness, and good flexibility. An underground power cable operates at temperatures above ambient and the polymeric insulation is usually crosslinked to provide mechanical strength to withstand the high temperatures. Chemical crosslinking is commonly employed; however, chemical crosslinking creates byproducts such as acetophenone, α-methylene styrene, and cumyl alcohol. The general practice is to decrease the concentration of the volatile crosslinking byproducts from the newly manufactured transmission class cables before they are commissioned into service. The concentration of the byproducts is decreased by treating the cables at a high temperature in a vacuum oven. At present, to determine the residual concentration of the byproducts, the treatment has to be stopped, a sample of the polymer has to be cut from the treated cable and the byproducts have to be extracted for several hours from the polymer before they can be analyzed. This paper describes a novel, non-destructive optical method for determining the concentration of the byproducts in XLPE prior to cable installation. The method involves in situ detection and measurement of thermoluminescence emitted by the crosslinking byproducts during the pretreatment of the cable, It is shown that the measurement of the intensity of thermoluminescence provides a direct indication of the concentration of the byproducts and that it is more sensitive than mass spectrometry     

电线电缆绝缘交联聚乙烯交联工艺的分析和对比

综述了电线电缆绝缘交联聚乙烯的几种交联工艺原理和工艺过程,并对过氧化物交联、硅烷(温水)交联和辐照交联的特点和应用范围,以及注意事项作了效详细分析和比较。     

Deep trapping centers in crosslinked polyethylene investigated bymolecular modeling and luminescence techniques

Space charge in crosslinked polyethylene (XLPE) has been detected under both ac and dc fields. Its role in electrical aging and breakdown is recognized, but not deeply understood. It is thought that identification of the trapping centers in this material would help improve the modeling of conduction and electrical aging as well as making possible the design of crosslinked materials with improved properties. We have developed theoretical and experimental approaches to this problem which emphasize the role of chemical traps acting as deep trapping centers. Molecular modeling is used to estimate the trap depth for negative and positive charge carriers associated with the main by-products of crosslinking reactions (using dicumyl peroxide as a crosslinking agent) since their aromatic structure makes them candidates for deep traps. Calculations on acetophenone, n-methyl styrene and cumyl alcohol show that they indeed can act as deep traps. Because such deep traps can act as recombination centers, their involvement in charge trapping can be checked in specially designed luminescence experiments. In our experiments, charges of both polarities are generated at the surface of the material under study by using a non-reactive cold plasma in helium. The analysis of the decay kinetics and emission spectrum of the subsequent luminescence allows us to define unambiguously the time range in which charge recombination is the dominant excitation process of the luminescence. The emission spectra obtained within this time range provide the optical fingerprint of chromophores acting as deep traps in the material. The low-density polyethylene (LDPE) doped with crosslinking byproducts and XLPE (film and cable peeling) have been investigated. Their role in charge trapping is apparent in the luminescence experiments and in space charge distribution analysis. In thermally treated XLPE, it is shown that other species strongly bonded to the polymer chain are also able to trap electrical charges     

中高压电力电缆半导电屏蔽电阻率特性分析

本文分析了GB/T12706.2～3-2002及GB/T1107.1～2-2002额定电压6～30kV及35kV和110kV挤包绝缘电力电缆及交联聚乙烯绝缘电力电缆标准中提出的半导电屏蔽电阻率技术指标规定的理论依据,探讨上述标准中指出老化前、后导体半导电屏蔽电阻率均不超过103Ω·m,绝缘半导电屏蔽电阻率均不超过5×102Ω·m规定值对电缆运行特性的影响。     

The influence of the water on water absorption and density of XLPEcable insulation

This paper presents the results of a continuing investigation into effect of water on water absorption and density of crosslinked polyethylene (XLPE). The experimental set up was made for the following XLPE cable insulations: steam and dry cured with water tree retardant crosslinked polyethylene (TR-XLPE) and without water tree retardant crosslinked polyethylene (natural XLPE). During tests, the tap water was injected (1) into the cable conductor with cable ends closed, (2) into the cable conductor with cable ends opened, and (3) into the metallic screen with cable ends opened. The XLPE cable insulation together with the water present in the cable was subjected to electrical stress and heating. The results were analyzed theoretically and experimentally. The aim of this paper is to present the results of the influence of the water on water absorption and density of various kinds of XLPE cable insulation in different service conditions     

基于ART2A-E的交叉互联XLPE电缆绝缘在线诊断技术研究

研究110 kV及以上电压等级的XLPE电缆绝缘的在线监测与诊断技术,确保电缆的安全可靠运行具有重要意义。笔者根据屏蔽层交叉互联接地XLPE电缆在线监测的特点,提出了基于ART2A-E(Adaptive Resonance Theory)神经网络的交叉互联电缆绝缘在线诊断方法。首先,通过分析电缆绝缘老化的特点以及电缆加速老化的实验结果,建立交叉互联XLPE电缆的仿真模型。然后,计算首末端A、B、C三相接地线电流与电缆初始安装时的接地线电流幅值和相位的相对劣化度得到12个特征量,并以此特征量作为ART2A-E的输入样本进行模式识别。仿真实验结果表明,ART2A-E神经网络可以识别发生在交叉互联中的任意一段电缆的绝缘故障,为交叉互联电缆的绝缘在线诊断开辟了新的途径。     

Effect of Thermal Overload on the Voltage Breakdown Strength of Service-Aged URD Cables

Present industry specifications allow thermoset insulated polymeric cables to be subjected to emergency conductor temperatures of up to 130°C. The effect of the high temperatures on cable integrity has been questioned. This study shows that cyclic, long-term or fast-rise application of 130°C to service-aged, water treed underground residential distribution (URD), crosslinked polyethylene (XLPE) insulated cables, result in an increase in dielectric strength. Contrary to what happens in new cables, an increase in temperature from ambient to 130°C also results in an increase in voltage breakdown strength. It appears that at high temperature, moisture and some remnant by-products of the crosslinking reaction such as volatiles, diffuse from the insulation, contributing to the higher levels of dielectric strength. It is shown that thermoplastic insulation shields on XLPE service-aged cables are adversely affected by emergency temperatures.     

±320kV直流电缆交联聚乙烯/三元乙丙橡胶附件击穿特性

高压直流电缆接头与终端为电缆系统故障的多发点,其击穿强度为直流输电系统安全稳定运行的重要基础。文中以±320 kV高压直流海底电缆中交联聚乙烯(cross linked polyethylene,XLPE)/三元乙丙橡胶(ethylene propylene diene monomer,EPDM)附件为研究对象。首先,研究电缆及附件负荷循环耐压试验,发现附件界面为击穿薄弱环节;其次,研究绝缘材料电导率随温度变化特性对电场分布的影响规律,通过有限元仿真模拟电缆空载和满载运行时附件的温度分布与电场分布,发现最大电场出现在电缆绝缘靠近附件应力锥一侧,为29.5 kV/mm,低于附件材料的击穿场强;最后,研究界面在直流电场下空间电荷特性对电场分布规律的影响,通过电声脉冲法测试复合叠层片状样品介质界面的空间电荷及其电场分布,发现场强畸变率约为100%~200%。同材料本征绝缘匹配相比,界面空间电荷积聚对附件内部电场造成的畸变程度更严重,在后续附件提升中应更注重开发抑制空间电荷的绝缘材料。     

交联聚乙烯交联度对材料击穿强度的影响

为了研究XLPE材料交联度对其电气性能的影响,制备不同交联度的XLPE样本并对其进行电气击穿实验,分析在不同的交联度区间范围内样本击穿场强变化。利用温度-时间控制法制备六组不同交联度的XLPE样本;利用差式扫描量热仪测量得到样本结晶度;利用交流变压器测量得到样本的击穿强度。实验结果表明,随着交联度上升,样本击穿场强呈先上升后下降趋势。在交联度为0%～75%区间范围内,样本击穿场强增加2%。在交联度为75%～88%范围内,样本击穿场强增加21.2%。而在交联度为88%～92%范围内,样本击穿场强下降5.3%。分析认为,样本的击穿强度与样本交联度和材料均匀程度有关。当交联度较低时,样本的击穿强度主要由样本交联度决定,随着交联度上升,样本击穿强度增加。但由于此时局部材料结构较为不均匀,因此击穿强度增加幅度不大。而当交联度上升至75%时,材料形成较为密集、均匀的三维网状结构,导致样本击穿场强大幅上升。而当交联度继续增加时,此时样本结晶度下降幅度较大,局部材料结构变得不均匀,导致样本击穿强度下降。