Journal ArticleDOI
Insulation performance of three types of micro-defects in inner epoxy insulators
TLDR
In this paper, an estimation method using electric field analysis is used for designing the defect shape and that the breakdown voltage depends on the three-dimensional shape of the defect, and the puncture properties and PD characteristics of artificial micro-defects of cracks, voids, and delaminations produced using an accurate estimation technique and precise production control were investigated and described.Abstract:
Gas insulated switchgear (GIS) has been widely applied in power equipment since the late 1960s due to its reliability and compactness. Because epoxy insulators in GIS are important insulation components that affect the dielectric withstand level and the equipment lifetime, high voltage tests and sensitive partial discharge (PD) tests have been carried out on them in the factory. If a latent defect occurs inside an actual epoxy insulator, its size is predicted to be small, such as a micro-defect, because it will have passed rigorous tests and multiple inspections at the factory. Although many studies have clarified the fundamental phenomena of deterioration caused by PD occurring due to defects in inner epoxy, little is known about the actual size of such defects and their effect on insulation properties. Therefore, to assess the risks associated with aging GIS equipment, it is essential to understand the actual size of latent defects in inner epoxy insulators of GIS and the impact the defects have on the insulation performance. The puncture properties and PD characteristics of artificial micro-defects of cracks, voids, and delaminations produced using an accurate estimation technique and precise production control were investigated and are described. The results suggest that an estimation method using electric field analysis is useful for designing the defect shape and that the breakdown voltage depends on the three-dimensional shape of the defect. Techniques for accurate estimation of small defects in epoxy resin and stable production of micro-defects have thus been achieved.read more
Citations
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Journal ArticleDOI
New aspects of UHF PD diagnostics on gas-insulated systems
TL;DR: In this article, the authors reviewed the recent and latest findings concerning the PD phenomenon and its propagation characteristics inside GIS as well as the PD measurement system verification methods and diagnostic technologies, and summarized typical examples.
Journal ArticleDOI
Mechanical, Thermal, and Electrical Properties of BN-Epoxy Composites Modified with Carboxyl-Terminated Butadiene Nitrile Liquid Rubber.
TL;DR: In this work, carboxyl-terminated butadiene nitrile liquid rubber was used to toughen the boron nitride-epoxy hybrid system and the effects of different contents of CTBN on the mechanical properties, thermal conductivity, glass transition temperature, thermal stability, and dielectric properties of the composites were investigated.
Journal ArticleDOI
Influence of addition of hydroxyl-terminated liquid nitrile rubber on dielectric properties and relaxation behavior of epoxy resin
TL;DR: In this paper, hydroxyl-terminated liquid nitrile rubber (HTBN) was used as the filler to toughen the epoxy resins to increase the toughness of composites.
Journal ArticleDOI
Gas-insulated switchgear PD signal analysis based on Hilbert-Huang transform with fractal parameters enhancement
TL;DR: In this paper, the authors proposed a method of partial discharge (PD) electrical signal analysis based on the Hilbert-Huang transform (HHT) with fractal feature enhancement, which can easily separate various defect types.
Journal ArticleDOI
Insulation characteristics of epoxy insulator with internal delamination-shaped micro-defects
TL;DR: In this paper, a short-time breakdown electric field (EF) was initially obtained and comparison was made with the breakdown EF for the void and crack defects to evaluate the breakdown risk with respect to the defect shape.
References
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Journal ArticleDOI
A generalized approach to partial discharge modeling
TL;DR: In this paper, a generalized partial discharge (PD) model is proposed to derive approximate relations between defect characteristics, insulation design parameters and test conditions on one side, and measurable PD characteristics on the other.
Journal ArticleDOI
Partial discharge. X. PD in gas-insulated substations-measurement and practical considerations
TL;DR: An overview of engineering practice related to partial discharge measurements in gas-insulated substations (GISs) is provided in this article, where the following questions are addressed: why measure PD in GIS?; in which phases of the life cycle should PD be measured?; what PD measurements are presently available?; and, what results can be expected under various measurement conditions?
Journal ArticleDOI
Influence of disconnecting part on propagation properties of PD-induced electromagnetic wave in model gis
Masayuki Hikita,Shinya Ohtsuka,Shigemitsu Okabe,Junichi Wada,Toshihiro Hoshino,Shiro Maruyama +5 more
TL;DR: In this paper, the effects of disconnecting part of a high voltage (HV) conductor like a circuit breaker or a disconnector in GIS tank were examined. And the authors showed that the PD-induced wave could propagate through the disconnecting parts with higher frequency components over the cutoff frequency components of TE11 mode.
Proceedings ArticleDOI
The voltage endurance of cast epoxy resin-II
S. A. Studniarz,Thomas W. Dakin +1 more
TL;DR: In this paper, the authors summarized the progress of an extensive study of the ac voltage endurance, extending from a single cycle to more than a year, for cast silica-filled epoxy resin, with recessed silver paint electrodes and cast-in aluminum electrodes, giving a nearly uniform electric field.
Journal ArticleDOI
A unique sensitivity verification combined with real-time partial-discharge identification method
TL;DR: In this article, the sensitivity verification with the ultra-high-frequency (UHF) method is discussed and a unique sensitivity verification, which is combined with real-time PD identification method, first enables us to identify the defects and thereafter to calibrate the apparent charge of each specified defect according to the sensitivity line.