An investigation into methods of modelling positive inhomogeneous-field breakdown and discharge process in SF6 with emphasis on the corona stabilisation phenomenon
Date
2016-07-20
Authors
Bhutt, Sanjeev
Journal Title
Journal ISSN
Volume Title
Publisher
Abstract
Corona stabilisation is not a well understood phenomenon, consequently a rigorous
theoretical description of how the merhanism operates does not exist. Furthermore,
postulates on the prcJ'.tse physical processes that occur during corona stabilised
breakdown are varied and conflicting. 1t was thus essential to develop a qualitative
theory of how the mechanism operates around which a quantitative model could be
constructed. To this aim, a detailed analysis of available modelling methods and
empirical data from published works was carried out. This analysis together with
additional finite elements modelling done as part of this work, leads to a proposed
qualitative model which serves as a basis for a quantitative model developed to
simulate corona stabilized breakdown from a fixed panicle defect. There is a
favorable comparison between the predictions of the model and published
measurements, thus imbuing optimism in the proposed method. The problem of
measuring t: .;true charge deployed in a discharge is discussed and an experiment is
designed to circumvent this problem.
Description
dissertatic,11 submitted to the Faculty of Engineering, University of the
Witwatersrand, Johannesburg, in fulfillment of the requirements for the degree of
Master of Science in Engineering,
I.:
Johannesburg, 1998