An analysis of pulse transformers

Harrison, Craig Brendon

An analysis of pulse transformers

dc.contributor.advisor	Bydder, E.L.
dc.contributor.author	Harrison, Craig Brendon
dc.date.accessioned	2022-11-15T03:42:05Z
dc.date.available	2022-11-15T03:42:05Z
dc.date.issued	1998
dc.date.updated	2022-11-15T03:40:36Z
dc.description.abstract	This thesis focuses on developing a comprehensive understanding of the behaviour of the output pulse transformer used in an electric fence energiser, a unique application which has received little attention in the literature. Maxwell’s Equations form the starting point for an investigation into the magnetisation of the magnetic core under high current pulse conditions. An equation is derived which describes the time dependent nature of the penetration of the magnetic field into the core material. The concept of a region of high permeability moving into the lamination as a result of rapid saturation is also developed. Quantitative results are obtained for the area of this high permeability region, both from the pulse magnetisation equation and by analytical methods. The analytical approach is also used to derive expressions for the pulse current, output voltage and power, and inductance. The analytical model of the output transformer provides much insight into the transformer’s behaviour, and into the influence upon performance of the various circuit elements. The description of pulse magnetisation is a key factor in the development of both analytical and electrical circuit models of the output transformer. The final part of the thesis considers the output transformer from the perspective of an electrical circuit model, which is developed as a direct representation of the physical transformer. The inductor-reluctance method is used to develop the model, and methods of calculating each parameter are derived, so that the final model may be obtained directly from the transformer’s specification without the need for experimental measurements. The electrical circuit model is implemented using a SPICE simulator, and an analysis of the transformer highlights the major design parameters. The description of pulse magnetisation, the analytical model and the electrical circuit model combine to provide a comprehensive description of the behaviour of the output transformer, and provide the tools required for design and further investigation of this application.
dc.format.mimetype	application/pdf
dc.identifier.uri	https://hdl.handle.net/10289/15337
dc.language.iso	en
dc.publisher	The University of Waikato
dc.rights	All items in Research Commons are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.title	An analysis of pulse transformers
dc.type	Thesis
pubs.place-of-publication	Hamilton, New Zealand	en_NZ
thesis.degree.grantor	The University of Waikato
thesis.degree.level	Doctoral
thesis.degree.name	Doctor of Philosophy (PhD)