Thesis (Ph.D. 1973) from the Dept. of Mathematics, University of Adelaide.

iii, 99 leaves : ill. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.1973) from the Dept. of Mathematics, University of Adelaide

Thesis (Ph.D) Dept. of Applied Mathematics, University of Adelaide 1981. / Typescript (photocopy).

M.Ing. / Open-wire telecommunications were developed in the 19th and early 20th centuries without any consideration of the deleterious effects of power lines; compatibility problems were later caused by the proximity of power lines and telephone lines. The coexistence of such systems requires careful planning in terms of energy coupled to the telephone lines; this induction can cause interference, as well as dangerous overvoltages in telephone circuits, and requires detailed studies of the effects of coupling between high voltage lines and telephone systems to be done. In terms of inductive co-ordination in South Africa, the minimum separation distances between high voltage power lines and communication systems are calculated only for power frequency and lower order harmonics (up to the 13th). The aim of the study was to explore the agreement between theory and measurement for frequencies from 50 Hz to the high order harmonic range of 4 kHz; this makes it possible to extend existing methods for predicting compatible separations to cases where high order harmonics (up to the 73rd) are present (balanced and unbalanced) on a 132 kV power line feeding a large aluminium smelter plant.

Thesis (Ph.D.) -- University of Adelaide, Dept. of Applied Mathematics, 1979.

69 leaves : tables ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.)--University of Adelaide, Dept. of Applied Mathematics, 1979

Typescript (photocopy) / iii, 152 leaves : ill. ; 30 cm. / Title page, contents and abstract only. The complete thesis in print form is available from the University Library. / Thesis (Ph.D.) Dept. of Applied Mathematics, University of Adelaide 1981

This work contributes toward research in the field of lightning performance of High Voltage Direct Current (HVDC) transmission lines, focusing on the impact of the line polarity on the incidence of line faults. Although there has been some recent research into the influence of polarity, there appears to be no confirmed effect that might influence the design of new lines. The research presents an investigation into the lightning performance of the two poles of the Cahora-Bassa HVDC transmission line. In order to compare the performance of the two polarities, the average lightning exposure over an 8-year period was confirmed to be very similar for both lines. Lightning stroke data from the South African Lightning Detection Network was correlated with fault times from the transmission-line protection scheme. The classification of the lightning related faults was used to determine the relative performance of the two poles, particularly in relation to polarity, and to infer if there was any influence of polarity on the lightning attachment process. This investigation for the Cahora-Bassa scheme shows that twenty-three out of twenty-five lightning related faults occurred on the positive pole. The results concur with performance experience on several HVDC lines from China and Canada, which indicate that lightning related faults favour the positive pole by a ratio of between 8:1 and 10:1. This represents a valuable contribution, which substantiates that HVDC line polarity has an influence on the lightning attachment process, and indicates that there is a need to re-examine the lightning shielding design for HVDC transmission lines. / GS2016

This master’s thesis is focused on the problems of designing telephone lines which are 7 km long with a step of 1 km. The thesis contains a detailed description of the basic parameters of metallic transmission lines. There is also briefly mentioned the issue of interfering the transmission lines. The main part is devoted to a system design of artificial lines connection, including printed circuit board design. The next section deals with a design of prototype controlling. The last part verifies the activity of implemented artificial lines.