Self-damping measurements of conductors with circular andtrapezoidal wires

Self-damping characteristics of three types of conductors with seven different sizes were studied. Conductor types considered were ACSR round and trapezoidal (TW) wires as well as self-damping (SD). The power method was used in the measurement of self-damping of all three types of conductors. For each conductor, damping measurements were made at three tension levels (10, 25 and 40% of rated tensile strength of conductor) for frequencies ranging from 5 to 55 Hz and normalized peak-to-peak amplitudes varying between 25/f to 150/f where f is frequency in Hz. Empirical relationships were derived to estimate the power dissipation values for all other frequency and amplitude levels. Results obtained from tests conducted on ACSR round and trapezoidal wire conductors of similar diameter indicated that the ACSR TW conductor in general has higher internal damping when compared to ACSR round wire conductor. However this trend was not necessarily observed at low frequencies. It was also noted that power dissipation increases with increase in size of the conductor     

输电线路新型节能导线的推广应用

结合国家电网公司基建新技术的推广应用,介绍了高导电率钢芯铝绞线、铝合金芯铝绞线和中强度全铝合金绞线的节能原理和性能,对比分析了3种新型节能导线在电气、机械特性等方面的技术差异,并对影响线路造价的敏感因素进行了分析,采用年费用和投资回收期法对导线的经济性进行了评价,最后提出了3种新型节能导线的工程应用范围,为节能导线的推广应用提供了参考。     

钢芯铝绞线低温机械性能的试验研究

针对钢芯铝绞线作为电力架空导线出现的断股、断线现象,采用对单钢线进行拉断力试验、对单铝线进行扭转卷绕试验的方法,对架空线路的钢芯铝绞线低温机械特性进行了研究.通过试验得出了低温下钢芯铝绞线拉断力和扭转特性等变化情况,并建议大跨越和山谷中的架空输电线路在低温气候条件下应加强运维措施.     

Guidelines for the selection and operation of bare ACSR conductors with regard to current-carrying capacity

Factors affecting the thermal ratings of bare overhead power conductors (in particular, ACSR conductors) are reviewed. Equations for calculating the current-carrying capacity (ampacity), loss of strength, and time-temperature characteristics of ACSR conductors are illustrated and parameters used in these equations are explained. Results have been obtained for ampacity, loss of strength and conductor temperature for a typical ACSR conductor (‘Drake’) in terms of various parameters such as ambient temperature, wind velocity, and (solar) insolation by means of Fortran programs written by the authors. These results are presented in graphical form. From them, meaningful conclusions are drawn regarding the means of evaluating permissible loading levels of transmission and distribution lines, especially lines of short to moderate length.The paper has been written primarily from the standpoint of showing how information currently available to utility industry personnel can be applied to evaluate the impact of various parameters on the permissible loading levels of bare conductors. The examples presented are typical of those of interest to the Tucson Electric Power Company and other utilities.     

Aged ACSR conductors. I. Testing procedures for conductors and lineitems

Field and laboratory tests of ACSR conductors and related line items from many of Ontario Hydro's older transmission lines are described. A nondestructive corrosion detector was modified for live line measurement of the loss of galvanizing from the steel cores of the ACSR conductors. Samples of conductors tested in the field have also undergone laboratory metallurgical investigation, and tests of fatigue, tensile strength, torsional ductility, and electrical performance. Extensive environmental studies identified corrosion products of ACSR conductors, the atmospheric factors responsible for corrosion, and the mechanisms by which corrosion takes place. It is concluded that the corrosion detector serves as a useful indicator of impeding end of conductor life, while the torsional ductility tests serve as a more precise condition indicator and can provide a guide for scheduling conductor replacement     

Electromagnetic Fields Generated by Overhead and Buried Short Conductors Part 1 - Single Conductor

The fundamental concepts and analytical development related to the low frequency electromagnetic fields generated by a single current-carrying conductor immersed in a medium of infinite extent and in a conducting half-space are described and discussed. It is shown that vertical conductors buried in earth are not detectable by above earth surface measurements of magnetic fields. Examples and numerical results involvinq energization of typical intact and broken single conductors are then described and commented on. It is shown that earth surface potentials and above earth magnetic fields are significantly distorted by a break in horizontal and oblique conductors. Finally, experimental measurements on a model with considerable heterogeneities confirm the significant influence of conductor discontinuities on the potential and magnetic field profiles.     

1000mm2大截面导线用防振锤设计

1660 kV宁东-山东直流输电示范工程一般线路使用1 000 mm2大截面钢芯铝绞线(型号JL/G3A-1000/45),需要采用加装防振锤来抑制此段线路微风振动.通过防振锤的保护频率的公式计算及导线自阻尼试验,最终确定JL/G3A-1000/45型导线需要用防振锤防护的频率为5-50 Hz.经过计算分析设计出合理的...     

宁东-山东±660kV直流输电示范工程的导线选型

宁东-山东±660kv直流输电示范工程（简称宁东工程）将“全寿命管理”理念贯穿在工程规划、设计、施工、运行全过程。在多分裂导线满足机械、电气性能及电磁环境限值要求的前提下,适当增加单导线的截面．可有效地降低电能在传输过程中的损耗,这对建设“资源节约型、环境友好型”输电线路有着重大的意义。通过对多个分裂型式和导线的截面组合方式进行技术经济比较,可知极导线分裂根数越多,导线直径越大．其电气性能就越好;但导线总截面不能太大,电流密度不能太低,否则投资过大;另外应考虑生产、施工、运行经验等因素对极导线方案的影响。综合比较后,4xJL/G3A-1000145导线的电晕特性满足限值要求．在多个电价和最大损耗小时数下,此方案的年费用最低,被推荐到宁东工程中。     

750kV输电用扩径型钢芯铝绞线关键技术探讨

我国将首次在西北电网750 kV输电工程上采用LGJK-300/50扩径型钢芯铝绞线。文中根据该导线《技术条件》提出的特殊要求,论述制造厂应如何解决扩径导线制造中面临的新问题。     

三峡工程500kV大容量输电线路用导线之二 主干线路大截面ACSR/AS-720/50的研制

三峡工程± 5 0 0 k V直流输电线路用大截面导线 ,目前虽然可以采用钢芯铝绞线 ,但铝包钢芯铝绞线更具有优良的性能。本文叙述制造 ACSR/ AS- 72 0 / 5 0铝包钢芯铝绞线的主要技术关键 ;原材料铝线和铝包钢线、ACSR/ AS- 72 0 / 5 0的性能 ;及其试验的结果和结论。     

ACCR导线的现场试验

ACCR导线是种新型导线,它看上去与传统的ACSR基本相同,但它是由合成材料和耐热铝合金组成.它的主要特点是高强度、重量轻(钢芯的1/3),良好的传导性能(钢芯的3倍)以及热膨胀系数低(钢芯的1/2),因此可以在低弛度重量大线段替代钢导线.美国在2个不同地点对这种新型导线进行现场试验,以验证其各种性能.     

碳纤维复合芯导线的施工工艺

碳纤维复合芯导线是一种节能型增容导线,具有节能降耗、重量轻等优点。碳纤维复合芯导线由于其自身结构特点,在施工过程中容易出现导线碳纤维复合芯棒内缩、导线铝股松弛、外层铝股损伤等现象。在220 kV 洛燕线路和洛振线路由常规钢芯铝绞线更换为碳纤维复合芯导线改造工程中,研制了专用卡线器,并采取了科学、合理的碳纤维复合芯导线的施工工艺,避免了上述不良现象发生,保证了工程质量及施工安全。     

Radial temperature distribution in ACSR conductors applying finiteelements

One of the most interesting aspects in the thermal analysis of an ACSR (aluminium conductors steel reinforced) conductor is the knowledge of the temperature distribution in its interior. These conductors have the problem of heterogeneous characteristics in their interior. This paper proposes a model, based on the finite-element technique, that considers temperature distribution in the interior of the conductor. The model relates the current distribution through the layers with the transmission of heat between them and with the exterior, both in steady state and in transient conditions     

等传输容量铜、铝导体海缆技术经济性比较

针对铜资源日益紧张造成电线电缆行业原材料成本压力的问题,分析铜、铝材料性能差异,完成等传输容量下铜、铝导体截面换算,依据现有生产工艺,采用解析法,完成铜、铝导体海缆参数计算,对比分析铜、铝导体海缆的技术经济性,进一步研究铝导体连接性能。结果表明：等传输容量条件下,铜、铝导体海缆单位质量近似相等,两者损耗及短路电流特性相近,铜导体海缆材料成本为铝导体海缆的110%~180%,采用交流氩弧焊可使铝导体接头具备良好电气与机械性能,铝导体海缆经济性更优。     

架空输电线路节能导线应用技术经济分析

介绍了铝合金芯铝绞线、钢芯高导电率硬铝绞线、中强度铝合金绞线3类节能型导线材料特点,结合节能导线试点工程,对节能导线与常规钢芯铝绞线进行了导线技术特性、经济性、施工等方面的综合分析比较,提出了3类新型节能导线在输电线路工程中的适用范围。研究表明,3类新型节能导线完全可以替换钢芯铝绞线在输电线路中应用,且具有良好的节能效果。     

Performance requirements for vibration dampers

An analysis method introduced in a recent paper has been applied to four ACSR conductors. Calculations are carried out to further illustrate the method, showing the relationship between wind energy input to the conductor and energy loss from the conductor when it is vibrating at a constant loop velocity equal to 200 mm/s. The difference between the two energy curves defines an energy gap or shortfall that must be supplied by vibration dampers. This energy gap is seen to depend strongly on the conductor tension, the conductor diameter, and the conductor span length. An illustration is given showing how well a Stockbridge damper or an impact damper fills the energy gap. One additional illustration is given applying the same principles to a triple-conductor bundle and an impact type of damping spacer. Finally, field tests conducted earlier on the four sample conductors are compared with the calculated results.     

Mechanical characteristics related to fault currents in bundle conductors

The flow of fault currents in bundled conductors induces an electromagnetic attraction between subconductors and thereby the bus conductor system to an extremely high level of tension. This tension, which is the most important factor in designing the mechanical strength of the system, is determined by a large number of parameters—the magnitude of the fault current, the size and number of the subconductors, spacer interval, the spring of the structure, and so on. Full-scale 63-kA class fault current tests were carried out on eight types of bus conductors used in 275-and 500-kV subconductors, and measurements of fluctuation in tension were used to clarify the relationship between the various parameters and maximum tension at fault time. A method also was devised for calculating maximum tension at fault time on the basis of the various parameters, and it has been applied in the mechanical strength design of the bus conductor system.     

导线标准冰厚的直径订正系数试验研究

架空输电线路导线覆冰可能导致电网系统发生机械或电气故障,因此,确定导线设计冰厚对电网的安全稳定运行具有十分重要的作用。确定架空输电线路导线设计冰厚时,需要通过线径订正公式将不同导线直径上的标准冰厚折算至设计导线上。通过人工气候室内覆冰试验获取相关覆冰数据,针对不同覆冰类型分别拟合了导线的直径订正系数。结果显示：雾凇和混合凇的导线直径订正系数随着线径的增加而减小,且雾凇减小的趋势较混合凇明显;雨凇的导线直径订正系数随着线径的增加而增加。     

带张力更换导线的施工方法应用探讨

以一条220 kV线路增容改造施工为例,介绍了一种将多个耐张段的普通钢锌铝绞线在耐张塔上用特定长度的钢丝绳套连接成一个大耐张段,利用张力机带张力回牵旧导线,再牵引耐热铝合金导线进行换线的施工方法,有效解决了现场施工场地狭小、线路下方交跨复杂、经济作物多、政策处理难等施工难点,取得了良好的经济效益和社会效益,可为同类导地线更换改造施工提供参考。