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# IEEE Transactions on Dielectrics and Electrical Insulation

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Displaying Results 1 - 20 of 20
• ### Electrical conduction in polyethylene with semiconductive electrodes

Publication Year: 1994, Page(s):224 - 230
Cited by:  Papers (35)
| | PDF (492 KB)

The electrical conduction characteristics of polyethylene with semiconductive electrodes have been investigated at electric fields of 10 to 600 kV/cm and at temperatures of 25 to 100°C. It was found that the conduction characteristics of the polyethylene were influenced not only by the constituents of the polyethylene but also the electrode materials. Space-charge-limited conduction was found ... View full abstract»

• ### Formulas to describe the bias and standard deviation of the ML-estimated Weibull shape parameter

Publication Year: 1994, Page(s):247 - 253
Cited by:  Papers (30)
| | PDF (500 KB)

The purpose of this paper is to present two formulas which can be used with the maximum likelihood method to estimate the Weibull shape parameter from uncensored data. The first formula unbiases the shape parameters for sample sizes of 3 and up. If this formula is added to the standard ML method, the bias is reduced to typically <0.3% (or even <0.05% depending on which set of test data is ch... View full abstract»

• ### Partial discharge measurements in SF6 and air using phase-resolved pulse-height analysis

Publication Year: 1994, Page(s):276 - 283
Cited by:  Papers (15)
| | PDF (472 KB)

Carries out a study on partial discharge (PD) phenomena in SF6 gas and tries to construct a diagnostic system capable of separating noise from observed PD signals for assessing the condition of insulation performance in power apparatus. The authors have constructed a computer-aided PD measuring system which permits a time-sequential data acquisition and phase-resolved pulse height analy... View full abstract»

• ### Charge trapping and conduction in pure and iodine-doped biaxially-oriented polypropylene

Publication Year: 1994, Page(s):213 - 223
Cited by:  Papers (20)
| | PDF (688 KB)

Study of charge trapping and conduction in pure and iodine doped biaxially oriented polypropylene (BOPP) is presented. Structural and chemical modifications induced by iodine were investigated using X-ray, optical and infrared methods. Optical spectra of doped BOPP show absorption at 290 nm from charge transfer complexes. X-ray examination revealed a decrease in crystallinity and crystallite size ... View full abstract»

• ### Transform relationship between Kerr-effect optical phase shift and nonuniform electric field distributions

Publication Year: 1994, Page(s):235 - 246
Cited by:  Papers (42)
| | PDF (720 KB)

Electric field distributions measured using the Kerr effect cause a phase shift between light components polarized parallel and perpendicular to the electric field, proportional to the magnitude squared of the electric field components in the plane perpendicular to light propagation integrated over the light path length. One wishes to recover the electric field distribution from measurements of li... View full abstract»

• ### Artificial neural networks for recognition of 3-d partial discharge patterns

Publication Year: 1994, Page(s):265 - 275
Cited by:  Papers (50)
| | PDF (728 KB)

Partial discharge (PD) measurements have been carried out over the years to assess insulation systems in power apparatus for their integrity and design deficiencies. Digital PD recording, processing and its presentation as 3-d patterns are recent trends in both industry and testing laboratories. Interpretation of these patterns can lead to evaluation of the cause of PD. A need arises to look for m... View full abstract»

• ### A new methodology to obtain accurate models for ferroelectrics with application to BaTiO3

Publication Year: 1994, Page(s):196 - 212
Cited by:  Papers (3)
| | PDF (1284 KB)

A new methodology based on semi-infinite optimization is proposed to obtain accurate yet simple phenomenological models for ferroelectric single crystals. The phenomenological models for ferroelectrics start with a Taylor series expansion of the governing thermodynamic potential, the elastic Gibbs function, in terms of the independent variables. The coefficients of the appropriately truncated seri... View full abstract»

• ### Influence of switching on dielectric properties of vacuum interrupters

Publication Year: 1994, Page(s):340 - 347
Cited by:  Papers (17)
| | PDF (548 KB)

This paper deals with the influence of switching operations closing without current/breaking without current', closing without current/breaking with rated current', and `closing without current/breaking of rated short-circuit current' on vacuum interrupter dielectric strength. Two types of commercially available vacuum interrupter with transverse magnetic field CuCr contacts were tested. Breakdo... View full abstract»

• ### Injection of a minimal space charge as mechanism for the initial phase of electrical polymer degradation

Publication Year: 1994, Page(s):231 - 234
Cited by:  Papers (4)
| | PDF (260 KB)

In this paper we present a model for polymer degradation during high-field stresses in analogy to the charge-to-breakdown concept in SiO 2. The model is based on space charge injection under high fields which leads to a cumulative effect as in radiation damage. A critical total injected charge density Qc is introduced, which is needed prior to any permanent damage. The assump... View full abstract»

• ### Application of artificial neural networks for optimization of electrode contour

Publication Year: 1994, Page(s):254 - 264
Cited by:  Papers (20)
| | PDF (720 KB)

In this paper artificial neural networks (NN) with supervised learning are proposed for HV electrode optimization. To demonstrate the effectiveness of artificial NN in electric field problems, a simple cylindrical electrode system is designed first where the stresses can be computed analytically. It is found that once trained, the NN can give results with mean absolute error of ~1% when compared w... View full abstract»

• ### Influence of voltage and load current on dc bipolar corona pulses

Publication Year: 1994, Page(s):284 - 293
Cited by:  Papers (3)
| | PDF (704 KB)

Digitizing oscilloscopes were used to observe anode and cathode corona pulses on a laboratory scale HVDC bipolar transmission line. Data was collected with the transmission line energized at a nominal voltage of ±60 kV with no load current. The effects of increased voltage and added load current were then separately investigated. Histograms show distributions of corona pulse amplitude and t... View full abstract»

• ### A study of dielectric relaxation in aluminosilicate-filled low-density polyethylene

Publication Year: 1994, Page(s):169 - 180
Cited by:  Papers (14)
| | PDF (756 KB)

Space charge formation in low-density polyethylene (LDPE) filled with zeolites and clays has been investigated by the thermally stimulated current method. The presence of fillers affects the dielectric properties due to additional dielectric relaxation phenomena, which depend on the structure of the inorganic filler. Pores or cages existing in the zeolite frame enable their compensated ions to mov... View full abstract»

• ### Streamer propagation over a liquid/solid interface

Publication Year: 1994, Page(s):348 - 350
Cited by:  Papers (3)
| | PDF (176 KB)

Danikas discusses and comments on a paper by Atten and Saker (see ibid., vol. 28, no. 2, pp. 230-42, 1993). He points out that, using a similar point/plane electrode arrangement and different insulating oils (dodecylbenzene oil and polybutene oil), he reached mostly the same conclusions regarding creepage discharge figures. He also discusses inception electric stress and streamer discharges. In re... View full abstract»

• ### Creepage discharge propagation in air and SF6 gas influenced by surface charge on solid dielectrics

Publication Year: 1994, Page(s):294 - 304
Cited by:  Papers (8)
| | PDF (736 KB)

Influence of surface charging on creepage discharge propagation in air and SF6 gas was investigated. The authors have employed a surface charging system using corona discharges, which permitted the deposition of surface charge on solid dielectrics with a given density distribution. By applying a lightning impulse across the charged surface of polyester film, they measured the discharge ... View full abstract»

• ### The dielectric properties of meat

Publication Year: 1994, Page(s):181 - 187
Cited by:  Papers (25)
| | PDF (488 KB)

The permittivity and conductivity of beef and chicken samples were measured in the frequency range of 1 Hz to 1 MHz. Differences were observed in these dielectric spectra for commercially purchased, as compared to freshly slaughtered samples. In particular, fresh samples display a greater directional anisotropy in their electrical properties and a smaller, frequency-dependent conductivity. Changes... View full abstract»

• ### Influence of sand/dust contamination on the breakdown of asymmetrical air gaps under switching impulses

Publication Year: 1994, Page(s):305 - 314
Cited by:  Papers (6)
| | PDF (676 KB)

This paper discusses the influence of airborne and surface-adhering sand/dust contamination on the breakdown characteristics of asymmetrical air gaps when subjected to standard switching impulses of both polarities. Extensive measurements of breakdown voltages and breakdown times are carried out under clean and polluted conditions using rod-plane and sphere-plane gaps. When positive switching impu... View full abstract»

• ### Pulsed electroacoustic method for measurement of charge accumulation in solid dielectrics

Publication Year: 1994, Page(s):188 - 195
Cited by:  Papers (235)
| | PDF (576 KB)

This paper describes the principle of the pulsed electroacoustic (PEA) method, which was developed a few years ago for profiling the space charge distribution in an acoustically homogeneous solid material. Initially the PEA method could indicate the space charge distribution in the materials only indirectly. Some data processing, for example deconvolution, was necessary to obtain the charge profil... View full abstract»

• ### Influence of surface microstructure on the electric and spectroscopic characteristics of dielectric surface flashover

Publication Year: 1994, Page(s):315 - 322
Cited by:  Papers (10)
| | PDF (664 KB)

Spectroscopic investigations were performed on high purity polycrystalline alumina in vacuum to understand the effect of surface microstructure as altered by mechanical surface treatment, on the optical as well as the electrical characteristics of dielectric surface flashover. HV pulses were applied to unpolished samples as well as to samples subjected to mechanical polishing by using SiC (268 to ... View full abstract»

• ### Assessing the risk of failure due to particle contamination of GIS using the UHF technique

Publication Year: 1994, Page(s):323 - 331
Cited by:  Papers (15)
| | PDF (684 KB)

The ultra high frequency (UHF) technique has been used to study the partial discharges produced by free conducting particles in gas insulated substations (GIS) with a view to predicting the probability of particle-triggered breakdown. Statistical techniques have been developed to describe the motion of a single particle. It is possible to identify whether the particle is capable of crossing to the... View full abstract»

• ### Electric field calculation for an axially-symmetric insulator with surface contamination

Publication Year: 1994, Page(s):332 - 339
Cited by:  Papers (18)
| | PDF (448 KB)

The classical method of integral equations was applied to determine the electrostatic field distribution on an insulator coated with a thin homogeneous surface layer. Results of calculations of the electric potential and the electric field on both uniformly and nonuniformly polluted model insulators coated with layers of different surface conductivities are presented in this paper. An application ... View full abstract»

## Aims & Scope

IEEE Transactions on Dielectrics and Electrical Insulation contains topics that are concerned with dielectric phenomena and measurements, with development and characterization of gaseous, vacuum, liquid and solid electrical insulating materials and systems; and with utilization of these materials in circuits and systems under condition of use.

Full Aims & Scope

Editor-in-Chief
Reuben Hackam