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# Conference Record of the 2000 IEEE International Symposium on Electrical Insulation (Cat. No.00CH37075)

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Displaying Results 1 - 25 of 124
• ### Studies on electric field enhancement due to presence of conducting particle on an insulating spacer as related to GIS

Publication Year: 2000, Page(s):300 - 303
Cited by:  Papers (1)
| | PDF (260 KB)

This paper discusses the electric stress distribution and the electric field enhancement due to a conducting particle at the solid-gas interface of a spacer of different profiles (angle) and materials (permittivity). The FEM has been employed to compute the tangential and normal components of electric field at the dielectric interface. The effects of the particle location on electric stress distri... View full abstract»

• ### A novel, compact instrument for the measurement and evaluation of relaxation currents conceived for on-site diagnosis of electric power apparatus

Publication Year: 2000, Page(s):161 - 167
Cited by:  Papers (36)
| | PDF (752 KB)

Ageing of insulation materials and systems may well be detected by quantitative measurements of their dielectric response. Such measurements can be performed in the frequency or time domain. In this contribution, a novel type of equipment based on relaxation current measurements is introduced which is designed for on-site tests of high voltage power apparatus. The introduction outlines the reasons... View full abstract»

• ### Flashover behavior of conducting particle on the spacer surface in compressed N2, 90%N2+10%SF6 and SF6 under lightning impulse stress

Publication Year: 2000, Page(s):296 - 299
Cited by:  Papers (1)
| | PDF (304 KB)

This paper deals partly with the influence of the gas pressure on the effects of surface conditioning in compressed N2 gas, 10%SF6+90%N2 mixture and pure SF6 gas up to 730 kPa. This influence is investigated using a cylindrical spacer model with an adhering particle on the surface under homogenous field conditions. The influence of the particle position ... View full abstract»

• ### Multiple stress aging of magnet wire by high frequency voltage pulses and high temperatures

Publication Year: 2000, Page(s):157 - 160
Cited by:  Papers (5)
| | PDF (448 KB)

This paper presents the results of multistress accelerated aging tests conducted on electrical insulation of fine gauge magnet wire used in high voltage coils of encapsulated flyback transformers. The aim of this work is to find an empirical electrical-thermal model to estimate the lifetime of the insulation exposed to multistress conditions including voltage and temperature at different high puls... View full abstract»

• ### Analysis of the sensitivity of the UHF PD measuring technique

Publication Year: 2000, Page(s):395 - 399
Cited by:  Papers (3)
| | PDF (372 KB)

Over the last years the UHF PD measuring technique has proven to be a very sensitive measuring tool for gas insulated systems. However, the sensitivity of the method strongly depends on the type of discharge and the number and type of GIS components between the discharge and the sensor. In this paper investigations regarding UHF signal propagation through GIS are analysed, in particular UHF signal... View full abstract»

• ### On-site diagnosis of power and special transformers

Publication Year: 2000, Page(s):362 - 367
Cited by:  Papers (10)
| | PDF (544 KB)

This paper deals-after a brief introduction to transformer life-management-with the difficult subject of condition assessment of transformers and the required or available diagnostic procedures. The On-site Diagnosis is achievable with a multitude of procedures if consequential approaches are taken. Equally important are the Fingerprints to characterize the initial status, the Periodic Check and o... View full abstract»

• ### Fault diagnosis of power transformer based on parsimonious covering set theory integrated with fuzzy logic

Publication Year: 2000, Page(s):271 - 274
Cited by:  Papers (1)
| | PDF (292 KB)

Parsimonious covering set theory integrated with probability reasoning and fuzzy logic is presented to diagnose the insulation condition of oil-immersed power transformer. The relevant diagnostic model is also constructed. In the modeling stage, the relationship between malfunction and symptom along with the possibility of malfunction are realized. Also, fuzzy borderline is considered for extracti... View full abstract»

• ### Optimum SF6-N2, SF6-air, SF6 -CO2 mixtures based on particle contamination

Publication Year: 2000, Page(s):292 - 295
Cited by:  Papers (2)
| | PDF (272 KB)

The design stress of sulphur hexafluoride Gas Insulated Switchgear (GIS) systems are limited by the harmful effects resulting from the almost inevitable presence of particulate contamination in GIS equipment. Mixing SF6 with other gas is a possible way of improving GIS performance under particle contamination condition. This paper studies the breakdown of SF6-gas mixture (SF<... View full abstract»

• ### Equigradient lines of electric field in stator slot, isodestruction lines of insulation and high voltage design of turbo- and hydrogenerators windings

Publication Year: 2000, Page(s):28 - 31
Cited by:  Papers (1)
| | PDF (340 KB)

The electrical aging of insulation used in high-voltage electrical machines in operation is investigated. Ionizational aging of multicomponent insulation is shown as a family of isodestruction lines which can be shown to relate to equigradient lines in the image of the electrical field. Results are then used to perfect the design of the insulation and high-voltage windings. The peculiarity of ioni... View full abstract»

• ### Changing insulation systems-benefits and problems

Publication Year: 2000, Page(s):148 - 156
Cited by:  Papers (1)
| | PDF (1076 KB)

In the last decade there have been numerous advances made in insulating tapes, resins, test methods and instrumentation. The impact of the application of the newer tapes and resins has produced step surges in insulation technology. The primary emphasis has been on the reduction of the total insulation in the machines to achieve higher output density, improved heat transfer, improved efficiency and... View full abstract»

• ### Measurement of solid dielectric surface temperature increment arising from partial discharge activity

Publication Year: 2000, Page(s):324 - 327
Cited by:  Papers (3)
| | PDF (300 KB)

Measurement of the temperature increment of the dielectric surface caused by partial discharge activity was carried out by means of non-invasive measuring system which takes an amount of infrared radiation energy emitted by the surface. The experiment was run in a point-dielectric-plane electrode arrangement with AC voltage up to 22 kV and frequency range from 200 to 1200 Hz. Samples of Epoxy resi... View full abstract»

• ### Partial discharge recognition of stator winding insulation based on artificial neural network

Publication Year: 2000, Page(s):9 - 12
Cited by:  Papers (1)
| | PDF (336 KB)

Partial discharge (PD) reflects insulation condition of high voltage electrical apparatus. Many large electrical machines tend to be subjected to large numbers of load cycles which often shorten the service time of the stator winding. PD accelerates insulation deterioration and there will be more serious PD phenomena at the continual development of insulation fault and before final breakdown of in... View full abstract»

• ### The application of new diagnostic protocols for the condition-based assessment of high-voltage electrical equipment

Publication Year: 2000, Page(s):377 - 381
Cited by:  Papers (1)
| | PDF (424 KB)

The diagnostic testing of insulation systems provides data that can be used to quantify the condition of high-voltage electrical equipment such as tap changers, circuit breakers, regulators and transformers. Using recently developed algorithms, condition codes for these types of equipment are generated using laboratory and field data. These codes are used to determine when maintenance is necessary... View full abstract»

• ### On the stochastic nature of SF6 partial discharges close to onset conditions

Publication Year: 2000, Page(s):390 - 394
Cited by:  Papers (1)
| | PDF (668 KB)

Discharges in compressed pure SF6 were produced in a plane-point-plane electrode configuration. The present report focuses on the pulse characteristics, as observed by recording real-time discharge frames via a fast digitizer. Sampling by frame of a duration of typically 1 ms with time resolution of 1 ns, has given access to the relation between consecutive pulses. Results obtained for ... View full abstract»

• ### Polymer concrete: a versatile, low-cost material for Asian electrical infrastructure systems

Publication Year: 2000, Page(s):356 - 361
Cited by:  Papers (1)
| | PDF (1248 KB)

This paper deals with polymer concrete, a highly-filled, low-cost composite material developed originally at Westinghouse R&D in the USA to be a versatile alternative to porcelain insulation, for a wide variety of applications. In over 20 years of field experience, polymer concrete has proven itself in a wide variety of environments all over the world. Besides insulation applications, polymer ... View full abstract»

• ### An investigation on the influencing factors on on-line insulation monitoring of HV apparatus

Publication Year: 2000, Page(s):81 - 84
Cited by:  Papers (1)
| | PDF (528 KB)

While on-line insulation monitoring of HV apparatus is giving more and more attention, how to analyze the data and increase the diagnosis veracity is becoming a new problem, for the online monitored data often vary. In this paper, a new on-line insulation monitoring system for HV instrument transformers, power transformers, bushings and MOA is presented. Then the influence of some factors on the m... View full abstract»

• ### Influence of high DC electrical fields on some aging properties of XLPE

Publication Year: 2000, Page(s):101 - 104
Cited by:  Papers (1)
| | PDF (260 KB)

The influence of high DC electrical fields (above 40 kV/mm) on some electrical properties and on the morphology of polyethylene (PE) is discussed from published experimental data. As it is well known, the polarization currents obtained under such fields are controlled by space charges. It is then possible to deduce the electrons mobility and concentration as a function of field. We show that the c... View full abstract»

• ### Low-k dielectrics for ULSI multilevel interconnections: thickness-dependent electrical and dielectric properties

Publication Year: 2000, Page(s):62 - 65
Cited by:  Papers (3)
| | PDF (232 KB)

Electrical and dielectric properties of a promising low-dielectric constant (low-k) crystalline polymer thin film are investigated for deep-submicron multilevel interconnection applications. Filmetrics F20, I-V characteristic measurement, fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD) are used to characterize the low-k film. The dc dielectric breakdown strength and the die... View full abstract»

• ### Development of knowledge rules for RVM for interpretation of the condition of transformer insulation

Publication Year: 2000, Page(s):267 - 270
Cited by:  Papers (6)
| | PDF (260 KB)

This paper describes the development of knowledge rules for the interpretation of Recovery Voltage Measurements (RVM) towards the ageing condition of oil-paper insulation. This method measures the polarization behaviour of the insulation. Paper insulated wire, as used in power transformers, is aged under controlled conditions. On the basis of this experiment as well as on basis of field tests on p... View full abstract»

• ### Effect of mixture of a small amount of CO2 in SF6 /N2 mixed gas on the insulation performance under nonuniform field

Publication Year: 2000, Page(s):288 - 291
| | PDF (340 KB)

Characteristics of partial discharge (PD) inception and breakdown voltages of SF6/N2/CO2 ternary gas mixture were investigated with AC high voltage under nonuniform electric field by changing the mixture ratio of each gas and the gas pressure from 0.1 to 0.6 MPa. When the mixture rate of SF6 in SF6 /N2 mixture was selected as 50%, w... View full abstract»

• ### Surface discharge along solid dielectrics in atmospheric air

Publication Year: 2000, Page(s):341 - 344
Cited by:  Papers (2)
| | PDF (244 KB)

This paper intends to contribute to the understanding of the propagation of surface discharges along an insulating surface under impulse voltage in atmospheric air. A concentric cylinder system has been used that allows to generate surface discharges propagating up to length of 0.6 m. A PE tube is mounted on the cylindrical conductor as an insulating layer. The HV is applied to the inner conductor... View full abstract»

• ### Techno-scientific aspects of epoxy mica vacuum pressure impregnation insulation system for rotating electrical machines and generators

Publication Year: 2000, Page(s):24 - 27
| | PDF (364 KB)

The paper examines the role of coil design, composition of insulating mica tapes, insulation application and coil manufacturing techniques in the further improvement of the dielectric and physical properties of the insulation system. This enables reduction in insulation thickness and further increases in the output for a unit volume. Impregnation compositions commonly utilized, and the scientific ... View full abstract»

• ### A survey of developments in insulation monitoring of power transformers

Publication Year: 2000, Page(s):141 - 147
Cited by:  Papers (11)
| | PDF (748 KB)

The aging infrastructure of large GSU and EHV power transformers built in the 60s and 70s poses a serious strategic issue for users worldwide. Catastrophic failures are escalating both in number and cost including environmental impacts. Extension of the useful life of power transformers is the single most important strategy for extending the life of power transmission and distribution infrastruc... View full abstract»

• ### Insulation life tests of multiple insulated wire cables in presence of high frequency and high temperature

Publication Year: 2000, Page(s):89 - 92
Cited by:  Papers (3)
| | PDF (264 KB)

The behaviour of insulated copper wire windings in the presence of power ac voltage and relatively high temperatures from the point of view of the insulation life is reasonably well known. However, the introduction of both modern multiple insulated wire cables and high frequency PWM-like supply voltages can give rise to a lower insulation life than in the previous case. A research program has been... View full abstract»

• ### Study of visible discharge onset and development on ice surfaces

Publication Year: 2000, Page(s):216 - 221
Cited by:  Papers (1)
| | PDF (716 KB)

This paper reports the results of a laboratory study on the first visible discharges developed on ice surfaces with micro air-gaps, using ultra high-speed photography. Two metallic hemispherical capped rods, 12 mm in diameter and half submerged in ice, were used. A relatively short air-gap was made at different locations in the ice, between the electrodes. The development of visible discharges, un... View full abstract»