Compression connectors for Stranded Aluminum power conductors

Twelve different commercial compression connectors for 240 mm/sup 2/ stranded aluminum cable conductors have been examined in order to identify and clarify the correlations between the quality of a connector and its design characteristics, assembly procedures, and other relevant parameters. The quality of the connectors is assessed with basis in resistance measurements during short-circuit tests and thermal cycling as specified by the IEC 61238-1 standard. Visual inspections of cross-sectioned connections, hardness measurements, and other examinations revealed that large mechanical deformations in connector-conductor interfaces significantly improve the quality. Connecting soft (annealed) conductors is considerably more difficult than hard-drawn conductors, but excellent results can be obtained if the work hardening during compression increases the conductor hardness to a level approaching that of hard conductors. The sequence in which the compression indents is made can be decisive for the quality of a connector. Unless the connector barrel or sleeve contains excessive amounts of contacting compound, it is advantageous to set the first indents at the ends of the barrel and the last ones in the middle.     

Bolted Connectors for Stranded Aluminum Power Conductors

Sixteen different commercial bolted connectors for 50 and 240 mm stranded aluminum cable conductors have been examined in order to identify and clarify the correlations between the quality of a connector and its design characteristics, material usage, assembly procedures, bolt numbers and configurations and other relevant parameters. The quality is assessed with basis in resistance measurements after short circuit testing and during thermal cycling as specified by the IEC 61238-1 standard. The tightening torque of the bolts was measured during connector assembly, and the resulting axial compressive forces were calculated. A very strong correlation is observed between this compressive force and the connector quality; large forces give connections with low and stables resistances. The various other design parameters considered are found to have significantly less or in some cases hardly any notable influence on the electrical test results.     

Making a Case for a New Connector

The emergence of quick lock connectors, particularly quick lock versions of the SMA and N connectors (QMA and QN, respectively), was an inevitable development in the RF connector industry and is of significant importance in that nearly 50% of all practical applications for RF connectors are currently supported by either SMA or N. Once QMA and QN can achieve similarity in cost and performance to the present SMA and N connectors, they will take the place of their predecessors in most applications, creating a huge new market. Our RF team has long been dedicated to research and development of these two connector types in the hopes of creating an optimal design. In this article, we will show some of the results of our research.     

Automation of the ANSI C119.4-1991 connector test

Automation of the ANSI C119.4-1991 connector test has been expensive. The ANSI test requires accelerated aging using AC current. The resistance of each connector must be measured periodically using DC current. These requirements generate the need for two power sources switched in and out by a computer-controlled relay. This relay must have contact current carrying capabilities equal to that of the cable on test. For large conductor sizes this expense becomes formidable. A method of making accurate ohm measurements of the connectors without connecting or disconnecting the conductor is given in this paper. Automation of the test can be established for a minimal investment with the information given. Automation will allow more information to be gathered, which will lead to the connector aging process being better understood and controlled     

电力电缆接头温度场分布的理论研究

电力电缆接头事故在电力电缆故障中占很大的比例,电力电缆接头的温度是反应其运行状态的重要参数。文中构建了电力电缆接头的简化结构模型,运用传热学的原理建立了电力电缆接头的温度场数学模型,应用有限元法分析了电力电缆接头的温度场分布。根据温度场的分布,把温度传感器合理地安装在接头的表面,可以通过电力电缆接头的结构特性、表面温度和环境温度,得到更加接近实际温度的接头线芯温度,能够及时准确地了解电力电缆接头的运行状况。     

手机中振子连接器的失效分析

研究了手机中失效振子连接器镀金触点后发现,接触表面污染、连接器制造及表面镀层材料缺陷是造成电接触故障的主要原因。表面污染物来自于尘土颗粒和微动磨损,主要集中在印制电路板(PCB)一侧,其成分包括C、O、S i、A l、S、C l、Na、N i等多种元素。测试结果表明,污染表面多达86%的测量点的接触电阻超过设计标准。随后通过有限元建立振子连接器模型进行模态分析,结果表明连接器固有频率与其工作振动频率相接近,容易引起触点接触正压力的降低和磨损加速,降低了振子连接器的接触可靠性。     

一种TNC型射频连接器电缆组件的研制

介绍了TNC-KY1-150型射频连接器电缆组件的研制过程,本产品在传统射频连接器的基础上对其不改变结构和性能,对射频连接器电缆组件外壳的一部分材料采用聚乙烯绝缘取代了传统的有色金属材料,从而大大降低了成本,同时也降低了工艺的难度,机械强度和绝缘性均有所提高.本产品的研制降低了TNC型射频连接器电缆组件的生产工艺和成本,极具推广价值,使在以后的设计中提供了更广的设计思路.     

The New IEEE-404 Test Specification for Joints Highlights the Importance of Connector Selection

On behalf of Hydro-Québec, IREQ undertook the evaluation of heat-shrinkable joints for 25-kV solid dielectric cable using the test schedule described in IEEE Standard 404-1986, a new specification containing higher performance requirements. Unexpectedly, the first batch of test samples failed. dramatically during the early stages of thermal heat and load cycling. Close examination of the joints followed by laboratory experiments, indicated thermal runaway of the connectors as the cause of failure, eventually attributed to faulty connector installation and compression. The experimental techniques and instrumentation used in this investigation are described in detail. The connector installation conditions were modified and the resulting satisfactory performance was demonstrated by testing samples for thermal stability under load-cycling conditions. New jointed-cable test samples were prepared and the splicing system successfully passed all the requirements of IEEE Standard 404-1986. It is now an accepted technique for the Hydro-Québec distribution system. This experience revealed that all aspects of a distribution system must be carefully considered when changes are made in the product performance requirements of any element. In fact all components of the system must be adjusted accordingly in order to provide the overall superior performance demanded by electrical utilities committed to reliable customer service.     

Partial discharge measurement in the ultra high frequency (UHF) range

The paper provides essentially a summary of PD measurements applying the UHF range in order to increase the detection threshold, to improve the localization accuracy and to perform on-line measurements of Partial Discharge (PD) in noisy environments. The electromagnetic UHF technique offers good signal to noise ratios, because external PD signals and disturbances can be shielded effectively. A new developed method allows the localization of PD in gas-insulated substations (GIS) by frequency domain measurements. The basic idea is the displacement law of Fourier transformation. The interference phenomena of superposed signals from two sensors give information about the time delay of the sensor signals. On-site PD measurements are made at cable connectors by means of monopole antennas housed in a barrel sleave, while the cable is in service. Thus a sensitive PD measurement even in noisy environment is possible. PDmeasurements on several 72 kV cable connectors were performed in an unshielded laboratory. On-site measurements during operation showed the great potential for condition assessment. For decoupling sensitive UHF PD signals from the inner of a power transformer tank UHF sensors applied through drain/oil valves are used. Experimental studies indicate that all relevant types of PD possibly occurring within a transformer emit high frequency spectra to be detected with UHF sensors. Furthermore in laboratory experiments and on-site measurements very moderate UHF signal attenuations have been observed.     

Microwave connector characterization

Coaxial connectors can be used either to probe the electrical properties of microwave circuits (e.g., microstrip, stripline) or as a permanent interface to the circuit. When used as a permanent interface, connectors can degrade circuit performance unless their electrical properties are characterized and accounted for during circuit design. Although it is more common to characterize microwave devices using scattering parameters (Collin, 1966) S_ij, we have chosen to utilize impedance parameters since they simplify the derivation of equations presented in this article. The proposed measurement-based method for connector characterization is exact in the sense that its theoretical foundation uses no approximations or assumptions     

USB 机械特性

提供了电缆、连接器及连接不同USB设备的电缆部件机械和电气方面的规范,包括尺寸、材料、电气及可靠性等方面的要求。同时说明了外部USB设备互连的最低要求,只要符合这些最低要求,也可以使用别的材料。USB电缆由2条电导线和2条信号线组成。USB可以在2种数据速率下工作;全速为12Mbit/s,要求使用带2条电导线和双绞信号线的具有屏蔽层的电缆;低速为1．5Mbit/s,降低了对电缆的要求,不需要使用蔽层和双绞信号线,连接器设计为热插拨,在USB插头的图标上提供了标识以便于正确定向。     

基于振荡波测试系统的10kV XLPE电缆终端半导电层缺陷检测效果分析

在10 kV XLPE电缆终端及接头安装过程中半导电层的制作不当会导致局部电场的畸变,引起局部放电,最后导致终端及接头的击穿故障。制作了电缆终端半导电层过长10 mm、无倒角、倒角不齐等3类缺陷,利用振荡波测试系统分别进行了检测。检测结果证明了该系统能够检测出该3类缺陷,但对不同缺陷的灵敏度不同。使用有限元仿真软件对相应的半导电层缺陷进行了电场仿真计算。仿真结果表明半导电层制作不当时局部最大场强是正常情况的4倍以上,证明了振荡波测试系统检测结果的正确性。     

220kV电力电缆附件用硅橡胶材料的吸潮特性分析

文章试验研究了电缆中间接头用硅橡胶材料与湿度环境的关系,理论分析和实验测试表明,电缆中间接头用硅橡胶材料的含水量随着环境湿度的增加而增加,但含水量增加的质量百分比很小。在严酷的湿度环境下,硅橡胶材料的含水量不超过其生产工艺控制水平1600×10^-6。所以硅橡胶材料在常温环境下运行或施工,其本体材料内的含水量不会有超标问题。     

基于弹性连接器的微动摩擦测试仪设计

为研究电连接器在微动中的摩擦特性及其对电接触的影响,设计了一种能够加速模拟连接器的微动并测量接触对间摩擦力大小的实验装置。给出了一种基于弹性材料连接器的微动摩擦测试机构的设计方法,介绍了仪器测试机构的工作原理并通过理论计算对其结构进行分析,通过有限元仿真和实验验证,该测试仪能够满足设计要求。     

水下插拔电连接器技术

本文介绍了一种“隔断水体原理”电连接器水下插拔接触件插合密封结构,并在此技术上进行连接器结构的探索,试制出可在水中进行插拔操作的满足要求的连接器.内容包括原理分析、结构设计、插合面的详细结构、界面处插针之间的绝缘方案、水下绝缘功能的分析、排水结构、关键技术等.     

110kV光纤复合电缆接头制作工艺研究

阐述了传统110 kV电缆、光纤及带光纤复合电缆中间接头安装技术;以实验室测试和现场安装为依据,探讨了110 kV光纤复合电缆中间接头的制作工艺,对其中关键工艺提出了多种解决方案,并总结出了较为合理的实施方法。     

特高压铝管预制式跳线接头防滑移方案研究

在特高压输电线路中,耐张段之间通常采用刚性跳线来导流,以减少跳线风偏和弧垂,压缩杆塔结构尺寸。铝管预制式跳线为刚性跳线的一种。以往设计形式的铝管接头部分由于轴向受力过大,或施工装夹不到位等原因,曾出现铝管接头滑移现象。为此,对铝管接头滑移问题进行了深入研究,提出了内接头攻丝配螺钉和铝管端部焊法兰盘2种改进方案,简要介绍了实施步骤、注意事项和试验情况,并将2种方案进行了分析比较。结果表明,2种方案都能有效地抑制铝管接头滑移,保证跳线及整个线路安全稳定运行。     

预制分支电缆连接体的制作及组合模具设计

针对分支电缆注塑模具设计中电缆规格多 ,干线电缆与支线电缆任意搭配给生产厂家注塑模具的制造带来了一定的困难 ,提出了采用组合模具 ,以减少模具的制造及镶件的制作 ,实践证明 ,对简化工艺 ,方便管理 ,降低成本有一定意义。本文介绍了分支连接体的制作及注塑模具设计的思路 ,以利于分支电缆产品的推广。     

智能型可分离连接器的研究与应用

安装在电缆与开关类设备连接处的可分离连接器,对内部接点过热的缺陷不能及时发现。分析了具备温度在线监测功能的智能型可分离连接器的研发重点,在此基础上提出了智能型可分离连接器的设计方案,并分析了智能型可分离连接器的优点。     

10kV XLPE电缆本体缺陷电场仿真分析

为了研究10 k V XLPE电缆本体受伤电场情况,防止电缆缺陷局部放电电场发展导致电缆接头击穿,通过分析XLPE电缆主要缺陷类型及原因来确定引起电缆故障的主要类型故障,然后利用有限元分析方法对电缆本体受伤情况电场进行仿真研究,最后根据仿真结果得出结论:在电缆本体空洞插入铁丝会造成电场畸变,严重时会造成绝缘击穿,为今后电缆线路故障分析提供参考。