Journal ArticleDOI
Electrical breakdown in high-voltage winding insulations of different manufacturing qualities
TLDR
In this article, the authors show that electrical tree propagation is the main electrical degradation mechanism that leads to breakdown of the main wall insulation and that poor impregnation of the insulation and type of taping can reduce time to breakdown significantly.Abstract:
Due to an increasing demand for new, or the refurbishment of power stations, high-voltage rotating machines continue to play a significant role in generating electrical energy. An important component of these machines is their electrical insulation. Although much research has been done to improve the material, about a quarter of all failures still are related to insulation problems. Research to improve winding insulation is very complex because a large number of factors influence insulation life, among them the raw materials, size of the mica tapes, geometrical characteristics of the bar and taping- or manufacturing techniques. The results show that electrical tree propagation is the main electrical degradation mechanism that leads to breakdown of the main wall insulation and that poor impregnation of the insulation and type of taping can reduce time to breakdown significantly.read more
Citations
More filters
Journal ArticleDOI
Design and Experimental Analysis of a Medium-Frequency Transformer for Solid-State Transformer Applications
TL;DR: In this article, the authors present an optimization routine and its underlying loss and thermal models, which are used to design a 166 kW/20 kHz transformer prototype achieving 99.4% efficiency at a power density of 44 kW/dm and a voltage conversion ratio of 3.5%.
Dielectric response and partial discharge measurements on stator insulation at varied low frequency
TL;DR: In this article, the main insulation of stator windings of high-voltage generators and motors is measured using an off-the-shelf stator-windings analyzer.
Dissertation
Mémoire d'habilitation à diriger des recherches
TL;DR: Dans le cas des CSP, Feder et Vardi ont propose la conjecture de the dichotomie, a savoir that chaque probleme CSP est soit facile (dans P) soit difficile (NP-complet), mais une trichotomie entre P, NP-complets et Pspace-completion est envisageable.
Journal ArticleDOI
The Insulation for Machines Having a High Lifespan Expectancy, Design, Tests and Acceptance Criteria Issues
Olivier Barre,Bellemain Napame +1 more
TL;DR: In this article, the authors give a step-by-step exhaustive review of one insulation layout and will take time to give a detailed report on the standards that are linked to insulation systems.
Journal ArticleDOI
The Electrical Insulation of Large Superconducting Magnets
TL;DR: In this paper, the authors discuss the build-up of electrical insulation in large superconducting magnets both from the manufacturing and operational point of view, and discuss the impact of the insulation design and manufacturing choices on the quality.
References
More filters
Book
Electrical degradation and breakdown in polymers
L.A. Dissado,John C. Fothergill +1 more
TL;DR: In this paper, the physical and chemical structure of polymers and their breakdown are discussed, along with the stochastic nature of break-down from empirical and modelling viewpoints, and practical implications and strategies for engineers.
Proceedings ArticleDOI
A survey of faults on induction motors in offshore oil industry, petrochemical industry, gas terminals and oil refineries
O.V. Thorsen,M. Dalva +1 more
TL;DR: A survey of the reliability of squirrel cage motors on board drilling, production, and other platforms offshore, together with cage motors in the petrochemical industry, gas terminals, and refineries onshore is presented in this article.
Journal Article
Report of large motor reliability survey of industrial and commercial installations. III
TL;DR: The results presented here of the 1982 survey are to investigate the data further to address questions generated by the results of the earlier paper, to find additional correlations of the reliability criteria of some of the more interesting categories, and to bring out more results and categories available from the survey data.
Journal ArticleDOI
Void formation and electrical breakdown in epoxy resin
TL;DR: In this paper, the long term behavior of epoxy resins subjected to high alternating electrical stress was studied using optical magnifications of up to 1500, a scanning electron microscope, and a high sensitivity discharge detector.