Design and Application of EHV and UHV Vertical Break and Vertical Reach Switches

This paper discusses the design and application of EHV and ultrahigh-voltage (UHV) disconnecting switches. It reports on the results of comprehensive electrical and mechanical tests conducted on 765-kV vertical break and vertical reach switches. Electrical clearances, both line-to-ground and line-to-line, are reviewed. Finally, statements are made concerning 1100-kV switch designs in view of possible reduction in switching surge impulse levels from 2.1 to 1.5 pu.