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Thor's Hammer Deflected: A history of the protection of power systems from lightning, with special reference to Queensland, 1950 to 1995

Electric power systems are a recent feature of community infrastructure, little more than a century having elapsed since the first public electricity supply was offered. The speed with which they have spread across the world, and the extent to which electricity has displaced other energy sources in commercial, industrial and domestic applications, has been quite remarkable. The widespread availability of a reliable supply of electricity has become one of the dominant factors in the lifestyle of the citizens of developed countries, and one of the differences between developed and developing countries. Yet not many histories of this remarkable industry have been written, and most of those have confined their attention to political and administrative matters, although technical issues have virtually dictated the pace of development of the industry. In the 1920s, when power systems began to spread beyond city centres, lightning became a major adverse factor in their capital costs, operating costs and reliability, and inadequate reliability reduced the rate of acceptance of electricity supply by the public, especially in rural areas. Although lightning has long inspired fear and wonder, its fundamental nature - the fact that it is an electrical discharge - was not known until less than three centuries ago, and the first measurements of lightning currents and voltages were not made until the middle 1920s, when instruments for measuring the electrical properties of lightning first became available. Intensive research programmes were undertaken in America, Britain, and some European countries from about 1925 onwards, but no research on the effects of lightning on power systems was undertaken in Australia until after 1950. This delay of almost three decades forced Australian power system engineers to base some very important aspects of power system design entirely upon data from other countries, which was of doubtful applicability in Australian conditions. During this period, the uncertainty over basic design data resulted in some power systems being over-insulated, with consequent waste of capital expenditure, while others were under-insulated, and had to be modified later to achieve adequate reliability. It is believed that this long delay in commencing lightning research in Australia was caused by a number of factors, including community attitudes to higher education and research (other than primary industry research), and the belief of many managers in the electricity supply industry that only the major manufacturers of electrical plant, located mainly in the United Kingdom and the United States of America, could successfully conduct power system research. In 1948 the Senate of the University of Queensland decided to replace the Chair of Engineering with four Chairs in separate branches of engineering. The founding Professor of Electrical Engineering, S.A. Prentice, was appointed in 1950 and soon decided to adopt lightning and its effects on power systems as the principal research thrust of the new Department. By the late 1950s, the University of Queensland had become the recognised centre of Australian research in lightning and high voltage insulation. With financial support from the electricity industry, the University completed a new high voltage laboratory in 1960, and soon began to be recognised overseas as a significant contributor to the world-wide search for knowledge in those areas. During the next fifteen years, the cooperative research programme of the University and the electricity industry developed fully, and valuable research was pursued in a number of areas, including the impulse strength and arc-quenching properties of Australian hardwoods used in poles and crossarms, the prediction of lightning outage rates of transmission lines, the causes of high lightning-failure rates in distribution systems, the performance of insulation under pollution conditions, and the validity of high voltage test procedures. The work frequently involved people from the electricity supply industry as well as people from the university, and attracted attention in overseas countries as well as in Australia. In 1974 Prentice reached retiring age, but the principal members of the staff he had recruited continued to produce research of high quality, and of considerable practical benefit to the electricity industry. By 1995, Prentice's principal staff members had reached or were approaching retirement, and the nature of lightning research had changed somewhat, with the principal interest turning to the details of the lightning stroke itself, and to protection of buildings and electronic equipment rather than power systems.

Identiferoai:union.ndltd.org:ADTP/253765
CreatorsMercer, Douglas Roy
Source SetsAustraliasian Digital Theses Program
Detected LanguageEnglish

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