The thesis reviews methods for the analysis of thyristor bridge
circuits using a digital computer. Tensor techniques based on the
work of Kron, and which deal efficiently and effectively with the
varying topology of the bridge circuits, are then used to analyse
both the 6-pulse and the l2-pulse fully-controlled circuits which
are the most common convertor configurations in hvdc transmission
systems. The work then extends to a more complete representation of
such a system, with the transmission line being represented by a
series of lumped T-section elements. Harmonic filtering is included
in the later stages of the work, with consideration given to the most
significant harmonics produced in the A.C. side of the invertors.
The elements of a typical hvdc transmission system have been assembled
in the laboratory, and the model system has been used as a check
on the accuracy of results provided by the computer programs.
A study has been made of the most common faults which occur in
an hvdc system, including misfiring, backfire, faults in the transmission
line, and the effects of a strike by lightning.
Close agreement between computed and experimental results has
been obtained over a wide range of normal and fault conditions.
A Doctoral Thesis. Submitted in partial fulfilment of the requirements for the award of Doctor of Philosophy of Loughborough University.