• ultra high voltage (UHV);
  • high-voltage equipment;
  • technical requirement;
  • circuit breaker;
  • disconnecting switch (DS);
  • earthing switch (ES);
  • high-speed grounding switch (HSGS);
  • secondary arc extinction;
  • transient recovery voltage (TRV);
  • metal oxide surge arrester;
  • IEC standards


CIGRE Study Committee A3 established WG A3.22 ‘Technical requirements for substation equipment exceeding 800 kV’ to review the state-of-the-art technical specifications for substation equipment exceeding 800kV in accordance with a request from IEC SC 17A. WG A3.22 conducted the initial surveys and submitted the first Technical Brochure on technical specifications for substation equipment such as gas circuit breaker (GCB), disconnecting switches (DS), earthing switches (ES), high-speed grounding switches (HSGS) and metal oxide surge arrester (MOSA) applied to 800 kV and 1100/1200 kV networks. The investigations include the insulation level, first-pole-to-clear factor, DC time constants, transient recovery voltage (TRV), line surge impedance and secondary arc extinction time. WG A3.22 will provide the technical background of all aspects of the available specifications with the intention of identifying the best practice for ultra high voltage (UHV) transmission systems. Copyright © 2009 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.