High-voltage auxiliary switchgear for power stations

Air-break switchgear has been used extensively for many years to control station auxiliaries. Vacuum and SF/sub 6/ techniques, already well established in the distribution field, are now being applied for the higher ratings and more onerous duties of switchgear in large fossil-fired and nuclear power stations. The author discusses power plant auxiliary systems and the environmental, mechanical and electrical operating conditions of the switchgear. The author then describes in detail the criteria affecting the choice of appropriate switchgear for auxiliaries. The choice of operating mechanisms and special requirements for nuclear power stations are also discussed.