EnglishHV Switchgear
HV switchgear refers to electrical control and protection assemblies rated for voltages above 52 kV AC, typically up to 1,100 kV for transmission-class applications. These assemblies incorporate circuit breakers, disconnectors, earthing switches, instrument transformers, and protective relays within metal-enclosed or gas-insulated enclosures. Insulation media include SF₆ gas, vacuum, or oil, with gas-insulated switchgear (GIS) offering compact footprints and reduced maintenance requirements. Design and testing conform to IEC 62271 and GB/T 7674 standards. Configuration options include single-busbar, double-busbar, and one-and-a-half breaker arrangements. Applications are found in transmission substations, large industrial power supplies, and grid interconnection points. Maintenance involves periodic inspection of gas density, contact wear, and operating mechanism functionality, along with dielectric and partial discharge monitoring.
