Development of 3‐in‐one high‐temperature superconducting cable

A three‐in‐one HTS cable has been developed. Its cable core is composed of a conductor and a shield wound with BSCCO and electrical insulation of the PPLP. The three cable cores are covered in thermal insulated stainless corrugated pipes. The BSCCO wires represent a dramatic innovation by virtue of a newly developed process named Controlled Over‐Pressure (CT‐OP). As a new cable technology, a 350‐m thermal insulation pipe was tested for 7 months to find that the life of the vacuum intensity is more than 10 years. The HTS cable with tension members was designed for installation into an underground duct. In addition, a fault current of 23 kA, 0.63 s, was applied to a sample cable with no damage to the BSCCO wires or the cable insulation. These technologies will be applied to the Albany project in the USA. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 162(1): 15–24, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20577     

Technical trends of high voltage and large capacity underground power cables

A 275 kV cross‐linked polyethylene (XLPE) cable with a large size conductor is mainly used for large‐capacity underground transmission lines in Japan. Furthermore, 275 kV gas insulated transmission line (GIL), which has a larger transmission capacity than 275 kV XLPE cable, has been developed and is in operation. The achievements regarding high voltage, large capacity underground transmission lines applied by the Chubu Electric Power Company will be introduced. In addition to these technologies, recent technical trends such as Rubber Blocked Joints (RBJ) will be presented. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

日本东京500 kV地下变电站及电缆的设计和建设

介绍日本东京市中心新丰洲线500kV地下变电站和新丰洲线电缆设计和建设的相关情况，新丰洲变电站是世界上目前唯一建成的500kV地下变电站，新丰洲线是世界上最长的500kV交联聚乙烯电缆线路。文章描述东京电网的地理接线情况以及500kV电缆规划，介绍新丰洲变电站的主要设备、电缆绝缘设计、电缆接头以及电缆的局放试验。     

中压交联聚乙烯电缆预制式接头施工工艺改进

10 kV交联聚乙烯电缆预制式接头的结构设计存在缺陷,易引发电缆故障,但可以通过施工工艺的改进予以解决。介绍了该预制式接头的基本结构、施工过程以及对其典型故障原因进行的试验性分析。针对该接头因其结构缺陷而引起故障这一根本原因,改进了接头的施工工艺,取得了良好的效果。     

500kV交联聚乙烯电力电缆隧道施工的关键技术

500kV交联聚乙烯(XLPE)电缆自重大、截面大等特点,增加了电力隧道内电缆敷设的技术含量和施工难度.以上海500kV静安(地下)变电站500kV电缆进线工程为例,重点讨论了500kV XLPE电缆施工中施工前期准备、电缆敷设、电缆接头和安全控制管理这4个方面的关键技术问题,可为其他电力电缆隧道内500kV电缆施工提供借鉴.     

35 kV GIL通管采用电缆替代技术研究

介绍了采用双拼1 200 mm2大截面电缆替代35 kV SF6气体绝缘输电线路(GIL)通管作为35 kV GIS开关柜与主变压器的连接应用.通过对电缆选型、敷设方式等研究,以及技术经济比较,得出采用大截面电缆替代技术的可行性和实施方案,为电力工程建设提供了技术支持.     

Results of lightning impulse tests for a 275‐kV full GIS substation

This paper describes the outline and results of the lightning impulse tests for a 275‐kV full GIS substation. The behavior of lightning surges is a very important factor for the rational design of substations and low‐voltage and control circuits inside the substations. For the above reason, we carried out lightning impulse tests for a new 275‐kV full GIS substation. In these tests, we measured voltage induced in low‐voltage and control circuits, transient characteristics of grounding grid, injected voltage and current waveforms, and so on. By investigating these data, we confirmed the behavior of lightning surges inside the substation. We also compared simulated waveforms by EMTP analysis with the measured waveforms. The simulated results agreed well with the measured results. © 2003 Wiley Periodicals, Inc. Electr Eng Jpn, 146(1): 46–58, 2004; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10230     

模块化变电站新型电缆通道应用研究

研究110 kV紧凑型模块化变电站通用设计方案,发现常规电缆通道在模块化通用设计方案中存在易与独立基础施工发生碰撞的问题。针对该问题提出一种融合电缆隧道与电缆沟优点的新型电缆通道构造样式,利用三维设计技术开展电缆敷设方案论证,并利用有限元软件进行结构论证,该问题得到解决并形成了新型电缆通道设计成果。     

深圳110kV高新站110kV GIS秀高Ⅰ线间隔缺陷分析

为了防止GIS的内部缺陷进一步发展造成事故,对GIS局部放电(局放)进行检测十分必要。笔者利用GIS特高频局放在线监测系统发现110 kV高新站110 kV GIS秀高Ⅰ线间隔有局部放电信号,并采取现场GIS局放带电测试、定位,以及进行一序列的开盖检查及缺陷排查,发现局放源位于110 kV高新站秀高Ⅰ线GIS A相电缆终端接头位置,最后更换了A相电缆终端接头后局放信号消失,避免了事故的发生,从而验证了GIS特高频局放在线监测系统检测GIS设备内电缆终端头故障的有效性,为较早地发现GIS内电缆终端头内部缺陷提供了有效检测方法和依据。     

Approach for wide use of diagnostic method for XLPE cables using harmonics in AC loss current

A water tree is one aspect of the degradation of XLPE cables used for underground distribution or transmission lines. We have developed the loss current method using the third harmonic in AC loss current for cable diagnosis. The harmonic components in loss current arise as a result of the nonlinear voltage– current characteristics of water trees. We confirmed that the third harmonic in the AC loss current has good correlation with respect to water tree growth and breakdown strength. After that, we applied this method to the actual 66‐kV XLPE cable lines. Up to now, results on over 130 lines have been obtained. In the case of cable lines terminated at gas‐insulated switchgear (GIS), we have to remove the lightning arrestor (LA) and the potential transformer (PT) from the test circuit. The reason is that we are afraid that each LA and PT disturbs the degradation signal from cable lines. It requires extra time (1 or 2 days) and costs more to remove the LA and PT in GIS from a circuit. In order to achieve easy and reasonable diagnosis, we have developed a new method for cable lines terminated at GIS by utilizing a technique that enables one to cancel the signal of the LA and PT from disturbed signal of the cable lines. We confirmed the effect of the new method through experiments with actual cables. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 165(4): 52–59, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20510     

我国高压及超高压交联聚乙烯绝缘电力电缆的应用与发展

本文介绍我国 110 k V及 2 2 0 k V交联聚乙烯 (XL PE)绝缘电缆及其附件的发展。高压 XL PE电缆是我国城市电网建设与改造工程采用地下电缆输电系统的首选产品。本文叙述 XL PE电缆的绝缘设计原则、绝缘质量控制要求 ,特别是绝缘中杂质、微孔以及绝缘与半导电屏蔽界面的微孔与凸起、绝缘收缩与交联工艺的关系 ,及电缆附件的选型与预制附件橡胶应力锥的设计方法。介绍了我国特大城市 ,上海、北京与广州高压电缆系统的应用情况。最后对我国 110 k V及 2 2 0 k V XL PE电缆及附件进一步发展以及 5 0 0 k V XL PE电缆系统发展与应用前景作了预测     

基于3D-CAD技术的智能变电站三维数字化设计探索

基于浙江嘉兴110千伏新生智能变工程设计的深化应用,提出了数字化三维变电设计与移交平台,对3D-CAD技术在变电设计与光电缆敷设中深化应用做了详细分析。由于面向全寿命周期,全过程采用一个统一的设计模型,涵盖电气各专业并实现协同设计,开创了智能变电站设计技术的新天地。     

Development of prefabricated joint for 275-kV XLPE cable

Application of XLPE cables to extra-high-voltage (EHV) transmission lines is expanding due to their excellent electrical properties and ease of maintenance, and 275-kV long-distance underground transmission lines are reaching the stage of practical utility. Extrusion molded joints (EMJs) are widely used as the XLPE cable joint for EHV transmission lines. However, EMJs have presented problems because of their insulation. They are formed on site through extruding and molding of crosslinkable PE like the cable, and need a long time for installation on site and higher jointing technique. The prefabricated joints (PJs), which are already applied to 154-kV transmission line, are installed on site by using the parts manufactured and tested in the factory, they require a shorter installation environment. This report introduces the results obtained regarding the improvement of the electrical property, workability and the performance of PJs, designed for 275-kV XLPE cable. These joints are planned to be used for 275-kV transmission lines from 1995     

500kV高压单芯电缆并联运行关键技术研究

随着线路负荷的不断上升,越来越多的单芯电缆线路采用同相多根并联的运行方式,而并联回路电流如何均匀分配始终是制约电缆同相并联运行的关键问题。通过对同相并联电缆等效电路的建模,推导了高压单芯电缆并联运行方式下各并联回路序阻抗的关系方程,并通过理论推导得出"镜像"布置方案可实现同相并联电缆间互阻抗相等,从而使同相并联电缆获得最佳均匀通流效果。在此基础上,依托某500 k V新建变电站工程,采用有限元法计算同相并联电缆在不同的空间布置方案下,单芯电缆同相并联运行时的电流分配特性。有限元计算结果表明,同相电缆的镜像布置方案可有效降低电缆电流的不平衡分配参数,提升并联电缆利用率。最后,结合常规地下/半地下500 k V GIS出线条件给出了推荐布置方案。     

Verification tests and insulation design method of cold dielectric superconducting cable

A High‐Temperature Superconducting (HTS) cable has a bulk power transmission capacity as a candidate for the replacement of aged cables and/or for the increase of the power transmission capacity, and its diameter is preferred to be smaller than the inner diameter of the duct for the existing cables. To reduce the diameter of HTS cable, the cold dielectric (CD)‐type electrical insulation in which a cable core is immersed into liquid nitrogen (LN₂) should be adopted, and the thickness of its electrical insulation layer has to be optimized. Since a partial discharge (PD) in the electrical insulation layer of the CD‐type HTS cable is considered as a major cause for the aging of the insulation layer, PD‐free design must be adopted for the CD‐type HTS cable. This paper describes a design method for the electrical insulation layer of the CD‐type HTS cable adopting the PD‐free design under AC stress, based on the experimental results such as a PD inception stress (PDIE), an impulse breakdown stress, and PD extinction characteristics under AC stress superimposed with an impulse stress. Moreover, the proposed design method was applied to a 500‐m HTS cable and was verified by a field test. © 2008 Wiley Periodicals, Inc. Electr Eng Jpn, 164(2): 25–36, 2008; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20512     

变电站电缆通道多参量采集和预警技术研究

针对变电站电缆通道数量的不断增加,电缆分布众多,某条线路的故障会带来极大的安全隐患。文中提出一种变电站电缆通道多参量采集和预警系统的设计方案,重点研究电力电缆的温度场和载流量。通过有限元分析软件,建立了10 kV单芯电缆四回路标准敷设电缆沟的几何模型,并采用割线法计算稳态载流量。通过实验分析了不同工况下的温度场和载流量。结果表明,对于在线电缆温度监测,只需要对温度最高的电缆进行监测,电缆铺设密度过高会导致电缆的载流量下降。该研究为中国变电站电缆通道多参量采集和预警技术的发展提供一定的参考和借鉴。     

Development of new‐type outdoor termination using composite insulator with SF6 gas: Commercial use for 77‐kV transmission lines and development for 154‐kV XLPE cable

Recently, composite insulators have been increasingly employed mainly for economic reasons. We have developed a new type of outdoor termination using a composite insulator, which can be installed horizontally on a steel tower in order to reduce the construction cost. In this outdoor termination, SF₆ gas is filled in the composite insulator and a cold shrinkable premolded rubber unit is applied instead of the combined use of a rubber‐molded stress relief cone, epoxy resin insulator and spring unit. The application of the composite insulator, SF₆ gas and cold shrinkable premolded rubber unit reduces the total weight and makes it possible to install the termination horizontally on the tower. The new‐type outdoor termination for 77‐kV XLPE cable has already been applied in commercial use and enabled a reduction of the construction costs for power transmission lines. A 154‐kV new‐type outdoor termination has been developed and its initial electrical tests were successfully completed. This paper describes the design and performance of both 77‐kV and 154‐kV new‐type outdoor termination, and a follow‐up survey of the 77‐kV new termination in a commercial use. © 2007 Wiley Periodicals, Inc. Electr Eng Jpn, 159(4): 18– 26, 2007; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.20511     

Thermal degradation characteristics of oil‐filled cable joint with extremely degraded tan δ oil

Much of oil‐filled (OF) cable has been used for a long time as 66‐ to 500‐kV extrahigh‐voltage cable. Sometimes we can see extremely degraded tan δ oil (several tens of percent of tan δ, for example) in joint boxes, etc. The values of tan δ calculated by a simple combination model of paper/oil show that the oil‐impregnated paper with such a high tan δ oil likewise has an extremely high tan δ, which must result in thermal breakdown. However, such an event has not taken place up to the present in actually operated transmission lines. This fact suggests that some mechanism for the suppression of tan δ has acted in the paper insulation impregnated with degraded tan δ oil. Therefore, we investigated in detail the tan δ characteristics of paper impregnated with extremely high tan δ oil. In addition, based on the investigation results, we developed a method for simulation of heat generation by dielectric loss in an OF cable joint (which has degraded tan δ oil). © 2011 Wiley Periodicals, Inc. Electr Eng Jpn, 178(1): 1–10, 2012; Published online in Wiley Online Library ( wileyonlinelibrary.com ). DOI 10.1002/eej.21184     

An over‐current withstanding design of superconducting power cables

In a design of HTS power cables, the over‐current withstanding design is very important. In a conventional case, when one of the 2‐circuit power cables failed, the other cable should transport the previous total power continuously. If we adopt this idea also in case of superconducting power cables, the rating current should be decided carefully. In this paper, the authors show a fundamental idea for a short‐time withstanding over‐current design of HTS power cables. © 2002 Wiley Periodicals, Inc. Electr Eng Jpn, 141(2): 34–40, 2002; Published online in Wiley InterScience ( www.interscience.wiley.com ). DOI 10.1002/eej.10051     

Practical Application of ±250‐kV DC‐XLPE Cable for Hokkaido–Honshu HVDC Link

The long‐term dc properties of DC‐XLPE insulation materials, which have been developed for dc use, were investigated. It was found that the lifetime of DC‐XLPE under dc voltage application is extended by the addition of nano‐sized filler. The time dependence of the space charge distribution at 50 kV/mm was observed for 7 days. Almost no accumulation of space charge in DC‐XLPE was found. The 250‐kV DC‐XLPE cables and accessories were manufactured and subjected to a type test and PQ test for use in the Hokkaido–Honshu dc link facility owned by the Electric Power Development Co., Ltd. These tests were performed under conditions that included a polarity reversal test for line commutated converter (LCC) systems as recommended in CIGRE TB 219. The test temperature was 90 °C. The type test and PQ test were successfully completed. The DC‐XLPE cable and accessories were installed in summer 2012 for the Hokkaido–Honshu dc link. After the installation of the dc extruded cable system, a dc high‐voltage test at 362.5 kV (=1.45 PU) for 15 min was successfully completed in accordance with CIGRE TB 219. This dc extruded cable system was put into operation in December 2012 as the world's highest‐voltage extruded dc cable in service and the world's first dc extruded cable for a LCC system including polarity reversal operation.