High-voltage switchgear

The paper begins by summarising the way in which the design of high-voltage (above 1 kV) switchgear has been affected by changes in the constitution of the manufacturing industry, both nationally and internationally, by advances in the knowledge and theory of arcs and circuit breaker operation, and by changing tendencies in service conditions that influence specification, rating and testing requirements. It describes the greatly increased application of circuit breakers and totally enclosed switchgear using sulphur hexafluoride as an arc-quenching medium and insulant, the commercial breakthrough of the vacuum interrupter and the universal acceptance and use of synthetic methods of testing circuit breakers. It then deals with ratings and service requirements, research and the theory of arcs and circuit breakers, standardisation and switchgear testing. It concludes by illustrating, with examples, the current trends in the design of apparatus, especially circuit breakers, and the layout and equipment of switchboards and substations.