This thesis describes a research investigation into novel designs of high
voltage pulse transformers using magnetic insulation, which is the only practicable
form of insulation for much of the equipment presently used in ultrahigh voltage
pulsed-power work, including transmission lines and plasma opening switches.
Although its use in transformers would bring important advantages in both size and
weight reductions, a number of seemingly insurmountable problems have however so
far prevented this.
Two novel arrangements are presented in this thesis: one of these is a 500 kV
transformer with self-magnetic insulation, and the other one is a 1 MV 'Tesla'
transformer with external magnetic insulation. It is shown that both of these overcome
the problems inherent in earlier designs and also offer considerable scope for further
development in a number of important areas. It is believed that they represent the first
working examples of magnetically-insulated transformers anywhere in the world.
Modelling considerations of the transformers developed include both
theoretical models and predicted characteristics. The filamentary technique used to
describe mathematically the arrangements being investigated involves decomposition
of the main conducting components into filamentary elements. The resulting
equivalent electrical network includes all the mutual interactions that exist between
the different filamentary elements, takes magnetic diffusion fully into account and
enables the resistances and self and mutual inductances that are effective under fast
transient conditions to be calculated. Theoretical results provided by the resulting
mathematical models have been successfully validated by comparison with reliable
Much of the work detailed in the thesis has already been presented in high
quality academic journals and at prestigious international conferences, and a solid
theoretical and experimental basis has been laid down for future development and
new progress into pulsed power system research.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University