Digital techniques in HV tests-summary of 1989 panel session

A panel session on digital techniques in high-voltage (HV) tests was held at the IEEE PES Summer Meeting in Long Beach, CA, in 1989. The authors present an outline of the panel session and list pertinent reference material. This panel addressed the question of how signal processing can be used to enhance high voltage tests and extract more information from them. The first part dealt with the evaluation of digitizers and records and the second with the application of digitizers to industrial testing     

Recent technologies of joints for HV and EHV XLPE cables in Japan

In Japan, XLPE cables are widely used for transmission lines and it is estimated that the ratio of XLPE will increase even more. The Investigation Committee of The Institute of Electrical Engineers of Japan (IEEJ), consisting of engineers from universities, all power utilities, all the major cable manufacturers, etc., has investigated the trend of the accessories (joint and termination) for XLPE cables of 66 kV and above in Japan for 3 years. This paper reports the results of this investigation. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

高压电力设备绝缘诊断的声学检测技术

对高电压设备绝缘缺陷的声学检测技术进行了分类,评述了国内外的声学敲击检测、声发射检测和超声检测等技术的原理、系统及优缺点,并探讨了绝缘状态声学诊断最有应用前景的检测技术。     

高压交联聚乙烯电缆绝缘老化及其诊断技术述评

对国内外部分高压交联聚乙烯(XLPE)电缆系统的绝缘损坏作了统计，分析了电缆及其附件绝缘老化原因和形态，叙述了XLPE电缆绝缘老化的机理。指出对高压电缆附件和缺乏径向防水构造的XLPE电缆需重视绝缘老化问题。对于XLPE电缆本体绝缘老化检测，认为高压级可比中压级简化。概述了国外绝缘老化诊断新技术的发展。最后，对局部放电检测绝缘老化技术方法作了试验探讨。     

Recent developments in thin film adhesion measurement

Interfacial fracture energies of thin films may be calculated using many different techniques. Nanoindentation and stressed overlayers are by far the most common and more reliable of the testing techniques. They depend on mechanics-based models to calculate the interfacial fracture energy of an interface using only the site specific material properties and the dimensions of the delaminated region, either in spontaneous buckle or indentation-induced blister form. This study will focus on four adhesion measurement techniques: spontaneous buckles, stressed overlayer-induced buckles, and nanoindentation-induced blisters with and without stressed overlayers, to demonstrate that the techniques will produce similar results for the measurement of adhesion energy. Films of tungsten (W), platinum (Pt), and titanium (Ti) on SiO/sub 2/ (amorphous glass) substrates are examined and values of interfacial fracture energies reported. Results of interfacial fracture energy calculated from spontaneous buckles and indentation-induced blisters compare well to one another and values are reported for the aforementioned films.     

Recent applications of linear analysis techniques

This paper is based on material presented at the Panel Session: Recent Applications of Linear Analysis Techniques conducted during the 1998 IEEE PES Summer Meeting. The topics discussed include: control system design; system identification; large scale system applications; simultaneous coordination of power system stabilisers and FACTS controllers; robust power system stabilisation; small signal stability analysis based on time-domain identified models; EM transient studies modal analysis; and power system dynamics nonlinearities, normal forms method     

电气测量辅助技术探讨

就精密电气测量系统信号的连接、电源、保护、接地等方面的问题进行了探讨.详细分析了接地线、电场噪声、磁场噪声对测量结果的影响,并提出解决问题的办法和保护措施.     

Power factor measurement and correction techniques

The prevailing method of power factor measurement is debatable. Certain methods are suggested in this paper with hints to improve power factor measurement and correction.     

无功电能测量新技术

介绍无功电能测量发展水平和不同类型无功电能表结构、特点，重点分析了具有多种人为无功测量方式的真无功电能表测量原理。     

A survey contactless measurement and testing techniques

Electron-beam testing technique includes photoemissive probing; electrooptic sampling; charge density probing and photoexcitation are analyzed. Among these techniques an ideal contactless probing system is simple, inexpensive to operate and compatible with the existing test equipment. It will not perturb the circuit and would measure electric signals with minimum crosstalk. Experimental results demonstrate that multiple optical test vectors can be input on the periphery of a DUT (device under test) with negligible crosstalk using this technique. The bandwidth of the test system would be compatible with picosecond data pulses and it would not be limited to certain materials. The approach offers increased testability and measurement of the "chip under test".     

Recent results in secondary voltage control of power systems

Recent results are reported on a pilot-point-based secondary voltage control in power systems. Similarities and differences compared to the optimal power flow methodology are described, and theoretical background for secondary voltage controller design is reviewed. Two complementary design problem formulations are reported, together with simulations on the New England 39 bus and Bonneville Power Administration 338 bus power system models. The results show the feasibility of the pilot-point approach and reveal the nature of the tradeoffs involved in secondary voltage controller designs     

脉冲功率技术一种高压ns脉冲测量的分压器

采用阻容式分压结构配合泰克P6015A高压探头,设计出了能测量脉冲的分压器,通过对比测量确定了该分压器的实用性.     

Characterization of a severely degraded silicone elastomer HV insulator-an aid to development of lifetime assessment techniques

A high voltage composite insulator showed severe degradation and failure of the silicone elastomer sheds following service in a substation environment. Sensitive analytical techniques were used to investigate the extent of degradation of the silicone elastomer (SiE). The polymer content of some surface regions decreased as degradation increased. This was quantified through observation by scanning electron microscopy (SEM), weight loss upon heating using thermogravimetric analysis (TGA), determination of surface "silica" levels in damaged areas by X-ray photoelectron spectroscopy (XPS) and Raman mapping through a cross-section of the elastomer producing a degradation depth profile. It is believed that due to the environmental conditions at the site of installation, the electric field may have reached corona onset threshold on parts of the elastomer surface. Because of the moist conditions the corona was maintained, effectively preventing the elastomer from regaining hydrophobicity and leading in time to severe degradation. This investigation has also identified techniques applicable to the assessment of condition of other, less damaged SiE insulators which may in turn lead to the prediction of the remaining useful lifetime.     

燃烧过程中碱金属原位测量技术综述

准东煤、生物质等高碱燃料在燃烧过程中释放的碱金属极易导致炉膛受热面沾污、结渣,影响锅炉运行的安全性,开展燃烧过程中碱金属定量测量对优化燃烧具有重要意义。将广泛采用的碱金属原位测量技术分为主动式、被动式2类:主动式包括激光诱导荧光技术、激光诱导击穿光谱技术与吸收光谱技术,被动式包括火焰发射光谱技术与图像处理技术;详细介绍了各种测量技术的基本原理及其在工业燃烧炉膛中的应用情况。主动式的碱金属原位测量技术对火焰几乎没有干扰,燃烧过程中原子和分子的光谱状态可以用很高的时间、空间分辨率观察,对碱金属的测量精度高,已经广泛用于实验室燃烧检测研究。而被动式的碱金属原位测量技术由于装备简单、对恶劣环境的适应性强,被证明有在现实工业条件下应用的潜力。最后,总结了碱金属原位测量技术的主要设备、应用、测量组分与检测限值,并指出了当前碱金属检测技术的不足及未来发展趋势。     

Space charge measurement techniques and space charge inpolyethylene

Recently, several new techniques such as LIPP, PIPS, PEA and TP methods have been developed to measure directly the space charge distributions in insulating polymers. Many papers have been published on space charge in insulating materials. In this paper, the space charge measurement techniques and space charge in polyethylene are reviewed. The space charge distributions in polyethylene depend strongly upon additives (antioxidants, antistatic agents, etc.), oxidation products, byproducts from the crosslinking reaction (acetophenone, etc.). Some of them enhance electron (or hole) injection from the electrode and, as a result, homo space charge is formed. Ionic carriers are supplied from some impurities to form hetero space charge. Space charge distributions are also sensitive to the electrode material and the interface between different materials. From the space charge behavior observed, the space charge effects on the high-field conduction and breakdown phenomena have been discussed quantitatively and some of the high-field phenomena in polyethylene have been elucidated     

Ultrasonic experiments illustrate Doppler and differentialtime-of-arrival measurement techniques

Two laboratory experiments based on 40 kHz ultrasonic signal measurements are described. The experiments illustrate techniques that are commonly applied to industrial applications. However, the lack of readily available hardware has limited their demonstration in the educational setting. The first experiment illustrates the Doppler effect as used in velocity measurement systems. The velocity of a moving ultrasonic source is computed from the frequency shift measured at the receiver. The second experiment illustrates differential time-of-flight measurements as used in navigational systems. The motion of a transmitter is computed from the differences in time-of-arrival at fixed receivers. The basic experiments are suitable for undergraduate labs. The signal analysis aspects of the experiments are appropriate for graduate-level digital signal processing courses     

高压静电场在高压交联电缆净化间中的应用

采用静电场吸附灰尘的原理结合传统净化工艺可显著改善高压交联聚乙烯绝缘电缆生产环境 ,生产实际中应用的结果证明它保证了电缆生产加料间环境净化 ,使杂质缺陷引起的电缆局放试验不合格的现象基本消除。     

Recent developments on high current measurement using current shunt

The Short‐circuit Testing Liaison (STL) is the organization that consists of high power testing laboratories of the world. Member laboratories perform short‐circuit tests under uniform interpretations of the IEC standards agreed through technical discussions and information exchanges among them. One of the recent projects that the STL has been working on is to establish uncertainty and traceability of high current measurement by international comparison tests with reference shunts. In concert with this project, the IEC Working Group is preparing the new standard for high current measurements. Copyright © 2007 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.     

Power substation magnetic field measurement using digital signalprocessing techniques

In this paper, a method is presented for measurement of power frequency magnetic fields due to distorted sinusoidal currents in power systems. The proposed method is an integral approach and consists of a multi-rate digital signal processor, an adaptive filter and an overlap processor. In field test, actual test results are accomplished by a standard area-type measurement setup to identify and characterize magnetic fields distribution of a 69 kV SF₆-gas insulated substation (GIS) using the proposed method     

A proposal for ground measurement techniques in substations fedexclusively by power cables

It was previously reported that when a fault to ground occurs in a substation fed exclusively by power cables, around 98% of the fault current can flow along the cable sheaths and auxiliary underground conductors, producing no local potential rise. This can modify greatly the results of ground measurements carried out in this type of substation, unless special care is taken and correction factors are suitably applied. The authors extend the experience gained during those measurement and determine a set of procedures that allow ground measurements to be made in substations fed solely by power cables. They set forth basic requirements for the measuring circuits and for handling the measured data. They then discuss power cable sheath characteristics in some step-down urban substations and ground measurement strategy for such substations