Digital recording techniques for electrical insulation measurements

The problems of measuring the characteristics of transient voltage and current waveforms occurring in high-voltage power systems are discussed, and the analog recorders that have been used in the past are reviewed. The theory of operation of digital recorders is described, and sources of recording errors are examined. Applications of digital oscilloscopes to measuring switching surges and partial discharges and to high-voltage impulse testing are discussed     

The chemistry of polyethylene insulation

The molecular structure of polyethylene and its copolymers is discussed, with particular attention to its effect on thermal and mechanical properties. The synthesis of polymers of various densities and of the copolymers is examined. The effects of changes in average molecular weight and of molecular weight distribution are considered. Vinyl-acetate-modified polyethylene, wire and cable coating, antioxidants and carbon black fillers, crosslinked wire insulation, peroxide crosslinked polyethylene, and water curable compounds are discussed     

新型电动汽车绝缘检测方法研究

电动汽车高压绝缘性能直接关系到司乘人员的人身安全,传统无源绝缘电阻测量方法存在抗干扰能力差、在特定条件下无法测量等缺点,具有一定的使用局限性.在深入分析无源绝缘电阻测量方法的基础上,提出一种新型的绝缘检测方案,通过电压注入的方法检测绝缘电阻,从根本上解决了正负母线对地对称绝缘故障无法测量的问题.实际样机检测证明,绝缘电...     

Electric fields and electrical insulation

The adoption of a field-theoretical approach to problems arising in the framework of electrical insulation is discussed with reference to six main topics, which have been addressed over the last 30 years. These include uniform field electrodes, Green's differential equation, electrode surface roughness, induced charge, electrostatic probes, and partial discharge transients, together with several follow-on aspects. Each topic is introduced and thereafter the progress achieved through the use of a field-theoretical approach is reviewed. Because the topics cover a wide spectrum of conditions, it is amply demonstrated that such an approach can lead to significant progress in many areas of electrical insulation.     

Fundamentals-radiation effects on electrical insulation

The basics of radiation interaction with the chemical structure of some common polymers are presented. Polymer chain crosslinking and scission, the two principal effects, are described, and stabilization of polymers to radiation is discussed. Effects of dose-rate temperature during radiation on service endurance are considered     

简述大电机绝缘的现代化

1前言 绝缘处于电机的心脏部位,非常关键。电机事故中绝大多数（约占70％以上）与绝缘有关。高电压、大电机对绝缘性能的要求很广、很高,其中包括电气、机械、热学和化学等方面,电场强度、击穿电压、介质损耗、机械强度、耐磨性能、导热能力、化学稳定性、耐热能力、耐电腐蚀能力、抗展能力等方面的指标必须得到保证。     

Treeing in mechanically prestressed electrical insulation

The technique of prestressing electrical insulation by the inclusion of fibers in tension during the curing process has been used to establish a region of balancing compressive stress adjacent to the fibers and through which growing electrical trees have to pass. It has been known for many years that compressive stress has a retarding effect on tree growth (and tensile stress has an accelerating effect). The compressive stress, therefore, set up due to prestressing decelerates tree growth and long treeing times have been observed. Room temperature cured epoxy resin readily demonstrates the prestressing phenomenon but, as a result of its relatively low glass transition temperature, it is unable to sustain the prestress at temperatures in excess of 40 /spl deg/C. Post curing at 100 /spl deg/C raises the glass transition temperature and although a greater initial fiber tension is required to produce the same degree of prestress, the prestress is subsequently sustainable at temperatures up to and beyond 80 /spl deg/C. This has been demonstrated by the determination of the remnant stress in the cast-in fibers using Raman spectroscopy and by the enhanced treeing times observed in high temperature cured samples.     

History of the electrical insulation conference

The Electrical Insulation Conference (EIC) Was organized in 1958. Four conferences were held before the establishment of the IEEE. Starting with the fifth conference in 1963, IEEE became a co-sponsor for this conference. The history of the various awards and recognitions sponsored by the EIC are listed. Efforts at expanding the scope of the technical activities and the interactions with related groups are discussed.     

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。     

The optimization of the production process for electrical insulation systems

Ways to optimize the production processes for slot and turn insulation are proposed.     

高电压大电机绝缘系统的现代化

我国高电压大容量发电机的主绝缘系统的发展。在提高电压等级、增加散热能力、延长使用寿命、确保运行可靠性等方面达到了世界先进水平。实现了现代化。介绍了重大科研成果,指出了今后的课题方向。     

The improvement of the electrical insulation of high voltage electrical machines

Comparative parameters are presented for the electrical insulation systems of high voltage electric machines. Composite insulation materials produced by different manufacturers are studied. The influence of the structure and composition of electrical insulation materials on the main operation parameters (electric strength, dielectric losses, the mechanical characteristics, and resistance to thermal cycling) of the insulation systems of electric machines is shown.     

The chemistry of ethylene propylene insulation. II

The basic chemistry of ethylene-propylene rubber (EPR) insulation is reviewed. EPR polymer structure, diene cure site, crystallinity, molecular weight and distribution, branching, and polymer properties are discussed. Manufacture, applications, compounding, curing, processing, and performance are also discussed. The important effect that compounding has on EPR insulation properties and performance is emphasized     

The chemistry of ethylene propylene insulation. I

The history, polymeric structure, and properties of ethylene-propylene rubber are reviewed. Polymer variables such as crystallinity, molecular weight, molecular weight distribution branching, and diene type and level are discussed     

High-humidity deterioration and internal structure change of epoxyresin for electrical insulation

Mechanical and electrical properties of filled epoxy were evaluated by accelerated aging under high humidity and high temperature. Significant changes in these properties arose from the slight water absorption. The presence of internal and irreversible flaws such as microscopic damage probably associated with the elastic inhomogeneities were predicted by scanning laser acoustic microscope attenuation, and surface structure changes were found by mercury porosimetry during the accelerated aging. It is considered that such internal and/or surface flaws play an important role of the changes in various properties due to water absorption     

Envisaging links between fundamental research in electrical insulation and electrical asset management

The trend of industrial and even institutional funding for research in the electrical energy world is going clearly in the direction of short-term, applied projects. On the one hand, this may be unavoidable with globalization and the fast increase in the energy needs of developing countries, while on the other hand it may affect in the long term the capability of developing base research in a sector that requires, more than many others, innovation and interdisciplinarity. Research financial institutions, such as the EC, EPRI, CRIEPI, etc., are going in the direction of promoting applied work. This can be seen with favor as long as it can correct distortions of the past, when fundamental research had been seen sometimes as a permanent exercise of speculations without oversight for an applied end; but the risk is to lose the fundamentals of knowledge which is the only way to promote real and stable innovation.     

Mechanical aspects of electrical treeing in solid insulation

Mechanical effects dominate the new theory, with the build-up of strain, fatigue failures and fracture due to shock waves being involved     

The evolution of electrical insulation technology in Japan

Today Japan has a leading position in insulation technology worldwide. The international community may be interested in learning how Japan attained this position. The history of this accomplishment will give invaluable suggestions to engineers and managers both in industrialized countries and in developing countries. It is the duty of Japanese engineers, in turn, to provide the historical information in a language understood by the Western community. This paper gives some insights into the history of Japanese insulation technology     

Cast electrical insulation quality enhancements through improvedfiller technology

There has been a significant amount of work documenting the benefits of using silane coupling agents in polymer composites. One intention of this article is to provide a brief overview of performance improvements they provide with respect to electrical insulation applications. However, the value of selecting the best method of silane usage has not received sufficient awareness in the marketplace. Therefore, more emphasis is placed on the implications of using both methods. The second major intention of this article is to offer ways to take advantage more effectively of the available benefits of specifying the filler system properties at the level of attention it deserves