Evaluation of maximum rotor temperatures in TEFC inverter-fedmotors

Based on the need to provide clearer application guidelines for motors supplied from adjustable-speed drives in Class I, Division 2 areas, the authors decided to conduct a test program to investigate the impact of adjustable-speed drives on totally-enclosed fan-cooled (TEFC) motor rotor temperatures. Hopefully, the results of these tests will foster industry discussion and increase collaboration among users and manufacturers     

Comparative Laboratory Evaluation of Premolded Joints for Medium Voltage Cables

This paper provides information on laboratory performance of 15 and 35 kV premolded joints from three manufacturers. Data on partial discharge, ac and hot impulse voltage breakdown tests, and dissection of breakdowns are presented for joints that were tested immediately after their assembly and after one year aging immersed in room temperature water (15-30degC), under operating voltage. The test program was repeated twice using joints acquired with a two-year interval. The two batches showed similar performance indicating that all three manufacturers provide consistent quality joints. AC breakdown strength of the joints practically did not change with aging. In contrast, their impulse breakdown strength decreased noticeably. Joints having partial discharge levels up to 5000 pC were included in the study. No obvious correlation was found between the presence of partial discharge and the joints ultimate dielectric strength.     

谈灯具泄漏电流测试线路中隔离测试变压器次级的接地

灯具泄漏电流测试线路中隔离测试变压器次级接地问题直接影响着测试结果的准确性。本文用试验数据和电路理论,分析了泄漏电流测试线路中隔离测试变压器次级接地的必要性,为灯具制造商与仪器制造商以及质检机构提供参考,从而为贯彻GB7000．1—2007（（灯具第1部分：一般要求与试验》标准提供指南。     

Leakage current-based testing of CMOS ICs

As semiconductor technology advances, testing integrated circuits (ICs) has become a challenging task. Semiconductor manufacturers use various methods, including the functional test, the structural test and the speed or delay test. One of the most popular test methods is the leakage current, or I/sub DDQ/, test. The article describes the advantages of I/sub DDQ/ tests. As transistor geometries are scaled further, I/sub DDQ/ values and variations are projected to increase. Thus, we need to understand the components of the variation in I/sub DDQ/ to develop the most suitable screening method. I/sub DDQ/ tests will continue to remain an important and integral component of a test suite. However, I/sub DDQ/ measurements will need to be supported by rigorous statistical data analysis to reduce yield loss in the future. Manufacturers must he able to define their own statistical procedures to tune pass/fail criteria optimally. It may not be possible to bin the chips until the data from a lot of wafers are collected. The trends in lot-to-lot or wafer-to-wafer variations in I/sub DDQ/ must be monitored and used in the analysis procedures.     

Successful testing of 345-kV XLPE cables and premolded joints atIREQ

Extruded polymeric cables and accessories are an alternative to self-contained fluid filled (SCFF) cables for extra-high-voltage (EHV) systems. Crosslinked polyethylene (XLPE) insulated cables have many advantages over the traditional fluid-filled pressurized cable system with the elimination of the hydraulic system and the associated equipment and complications during the installation and operation/maintenance of such systems. Other advantages of the extruded cable system arise from the new accessory technologies and the use of splices and terminations that are prefabricated and pretested in the factory and require less time to install on site. Concerns over the long term reliability of high voltage cable systems, in particular the accessories and the lack of service experience above 300 kV led to the decision of Hydro-Quebec to carry out a prequalification (long-term) test program to assess the reliability of the cable materials and to verify the cable and accessory installation methods to be employed. The cables were installed in duct banks and manholes simulating actual installation conditions used in Hydro-Quebec underground cable network. This paper describes the program and results of the prequalification tests of 345-kV XLPE cables and accessories performed at Hydro-Quebec's Research Institute (IREQ) in partnership with three international cable manufacturers, Alcatel, Fujikura and Pirelli     

Protection of asynchronized turbogenerator against loss of dynamical stability

It is shown that there is a great need to develop protection for an asynchronized turbogenerator against the loss of dynamical stability because all of the currently existing asynchronized turbogenerators operate without this protection. A program of priority works on the protection creation is developed. The fundamental possibility of using the equipment available from various manufacturers taking into account features of asynchronized turbogenerator regimes is demonstrated.     

灵宝背靠背换流站二次设备联合测试

灵宝背靠背直流工程中,换流站控制系统及直流系统保护首次采用国产设备,分别配置了两个完整套,两 套分别基于ABB公司和SIEMENS公司的引进技术。两套系统既需满足工程的统一规范要求,又要完成相互之 间、以及与国产一次设备及其它二次设备的接口。因此,换流站二次成套技术难度较大。为了提前发现问题,尽量 减少现场调试的风险,网联公司使用RTDS仿真系统完成了灵宝换流站控制系统/直流系统保护,以及相关二次设 备的功能、性能、接口的联合测试,测试项目约达280项次。     

MULTITEST II: a program for the generation, correction, andanalysis of multiple choice tests

Multitest II is a program for the generation, correction, and analysis of multiple-choice examinations. The program is written in Pascal and has been implemented for the IBM-PC and compatible microcomputers, and for the VAX minicomputer. The program allows the random generation of tests from a master test, and supports several types of multiple-choice tests. The tests are graded by means of a user-definable numerical grading system. Certain statistical analyses can be performed on the tests results. A special effort was made when designing the program to make it highly error-proof. This was achieved by using menus included in the program. The prompts were designed to elicit very specific and simple answers. As a result, the program can be handled by personnel without special computer training     

浅析GB 14048.2断路器EMC试验的新旧标准差异

针对即将实施的断路器新版标准GB 14048.2—2008,从电磁兼容性试验角度分析其与旧标准的差异。按照产品分类,对于附录J、F、B、N中相关试验内容和要求的差异进行说明,指出了制造商和试验人员在进行3C认证试验时应注意的问题。     

500kV继电保护故障信息处理系统动模试验方案

通过分析继电保护故障信息处理系统在保护与子站通信方式、保护信息的完整性、保护信息分类、通信规约和高级应用等方面存在的问题以及常规测试的局限性,提出了基于RTDS(realtimedigitalsimulation)的继电保护故障信息处理系统动模试验方案,通过该方案能很好地测试继电保护故障信息处理系统所提供保护信息的完整性、通信能力和各种高级应用功能。采用该方案在华东电力试验研究所对一些厂商的系统进行了测试,取得了较好的效果。     

Long-term testing of a low-loss 800 kV PPLP insulated SCFF cable

This paper describes the dielectric and accelerated aging tests on an 800 kV AC polypropylene laminated paper (PPLP) insulated low-loss SCFF cable prototype. The test program was developed to validate the PPLP technology for future Hydro-Quebec 765 kV St-Lawrence under-river crossings. The paper reports on the cable and accessories characteristics, the test line construction, the test program, and the main results obtained. The successfully completed program has shown the overall very good performance of the cable and its accessories     

变电站自动化系统互操作实验建议

实现不同厂家设备的互操作是IEC 61850标准的主要目标。为此,不同厂家之间需要进行必要的互操作实验。在对国外历次IEC 61850互操作实验研究的基础上,建议国内厂家按照逐次逼近的原则,分阶段进行实验,在实验过程中使用必要的监视、分析工具。     

接地装置测试仪抗工频干扰能力测试分析

重点研究了接地装置测试仪抗工频干扰能力测试的方法,通过搭建试验回路,对多个厂家的接地装置测试仪进行了抗工频干扰能力测试,测试结果表明,不少厂家的接地装置测试仪抗工频干扰能力差,不能满足现场测试要求,因此,建议在仪器选购时,对仪器的抗工频干扰能力进行考核。     

试验线段电晕测量技术及结果

为了配合对特高压试验线段电晕测量的研究,介绍了500kV试验线段电晕测量方法(包括测试仪器、信号取样方式、试验方法等问题)及结果并探讨了特高压试验线段电晕损失测试的几个关键问题。在国内有关输电线路电晕损失的各种论述中,基本上是引用国外的实测结果,一般认为国内从未对电晕进行过实测。早在80年代,作为武汉高压研究所承担的国家“六五”攻关项目的重要部分,即在500kV试验线段上对各种气象条件下,3种分裂方式导线的电晕损失和无线电干扰水平进行了测试。试验的目的是为了论证3×400分裂导线在技术、经济上的可行性,探索采用3×300分裂导线的可能性及技术条件,但这些结果从未公开发表;附录中给出了全部的电晕损失测量结果,其测试方法、结果等对特高压试验线段电晕损失的计算和实测亦有借鉴作用。     

IEC60598—1：2008标准中保护导体电流和接触电流测试解析（上）

IEC60598—1：2008《灯具第1部分：一般要求与试验》中新增了保护争体电流和接触电流的测试要求,对其中的测试方法及要求进行分析,明确了试验条件、仪器设备、操作方法及限值的选取方法,可以为使用标准的相关企业、质检机构及设备制造商提供指导和参考。     

两电平电压源换流器的损耗计算方法

功率损耗影响电压源换流器的效率,是实际工程应用中必须关注的一个问题.采用多项式方法拟合绝缘栅双极晶体管IGBT(insulated gate bipolar transisitor)厂商提供的特性曲线,建立多项式损耗模型,给出了适用性强的IGBT模块损耗计算方法.在LabVIEW下编写了损耗计算程序,对两电平电压源换流...     

High voltage VLF testing of power cables

This publication describes a laboratory test program conducted with the objective to develop a test that would replace the existing DC withstand test. The article describes the methodology used to establish the voltage duration and magnitude of VLF (0.1 Hz) high voltage field tests suitable for crosslinked polyethylene (XLPE) insulated power cable. The results show that the voltage breakdown of laboratory aged XLPE cable at 0.1 Hz is approximately equal to that at 60 Hz, that proof tests at 0.1 Hz cause very little damage to the cable, and that 0.1 Hz testing appears to be a satisfactory alternate to DC testing. Preliminary values are suggested for voltage magnitude and time duration of cable acceptance, maintenance and proof tests at 0.1 Hz for XLPE cable rated up to 35 kV. A program is underway to similarly evaluate samples of service-aged XLPE cable; as well as to demonstrate the use of the preliminary test values at typical utility installations     

Behaviour of the DC leakage currents of polymeric metal oxide surgearresters in water penetration tests

The behaviour of seven commercially available polymer-housed metal oxide surge arrester types was studied in +70°C and boiling water immersion tests. The DC leakage current of the arresters was used to diagnose the humidity penetration inside an arrester. The recovery features after an immersion test for different arrester types were measured and discussed. Together with the immersion and recovery tests, a humidity penetration test in very humid air was performed. For the first time, the behaviour of different arrester types in immersion tests was compared to their behaviour in a humidity penetration test with realistic ambient conditions. The resistance to moisture penetration varied greatly in the arrester types tested. Also, recovery of the DC leakage current varied between the arrester types depending on their structure. The results from the tests in very humid air indicate similar arrester behaviour than the results from other tests and suggest ideas for diagnosing arrester behaviour     

电力调度软交换系统的互联互通设计*

国家电网公司在传统电路交换网向基于软交换技术的调度交换网演进的过程中,各试点还未对IP组网或TDM+IP混合组网下的异厂家调度系统展开全面的调度业务互通,缺乏此互通经验。文章提出在实验室环境下,对主流厂家调度系统间进行互联互通的验证设计方案,并针对测试过程中存在的调度业务互通问题,提供具体可行的互通标准规范。各厂家按照此规范进行统一改进后,良好的解决了异厂家调度系统间的互通问题,为加快电力调度交换网演进步伐提供技术支撑。     

Design and operational testing on thyristor modules for the SVCKemps Creek

The design and operational testing of valves for the SVC (static Var compensator) to be installed at Kemps Creek substation in Australia are discussed. The most important design principles and features of the thyristor modules are given. Operational tests carried out on the thyristor modules are described; for this test program, noteworthy test circuits have been set up to perform both TSR (thyristor switched reactor) and TSC (thyristor switched capacitor) fault current tests with high test values and special waveforms. Test results and test circuits are presented