110 kV GIS switchgear
1. Compactness: Significantly smaller dimensions compared to traditional open-type switchgear (AIS), making them an ideal solution for urban underground substations and projects with limited site area.
2. High operational reliability: All high-voltage current-carrying parts are enclosed in sealed metal housings, protecting them from rain, snow, dust, pollution, and condensation, ensuring a low failure rate.
3. Minimal maintenance requirements: Internal components are protected from environmental influences; routine maintenance is limited to monitoring sulfur hexafluoride (SF₆) gas density, eliminating the need for frequent contact inspections.
4. High resistance to external conditions: The equipment is suitable for operation in high-altitude areas, coastal zones (exposure to salt spray), extremely low and high temperatures, as well as in areas with severe air pollution; installation is possible both indoors and outdoors.
5. Factory assembly: The modules are assembled and tested under factory conditions; on-site, only their interconnection and gas filling are required, which significantly reduces installation time.
6. High level of safety: The metal housing is reliably grounded, with no exposed live parts, ensuring personnel safety; explosion-proof pressure relief devices are provided to protect the equipment in the event of an emergency.
This is a complete high-voltage gas-insulated switchgear (GIS) with SF₆ insulation and a fully enclosed design. Inside a grounded metal tank filled with SF₆ gas, which provides insulation and arc quenching, the following components are housed: a circuit breaker, a three-position disconnector, an earthing switch, a current transformer (CT), a voltage transformer, and busbars.
1. Main Parameters
Rated voltage: 126 kV (for 110 kV networks)
Rated current: up to 4000 A
Rated short-circuit breaking current: 50 kA
Mechanical endurance: 10,000 operations; electrical endurance: 20 operations
Application areas: indoor and outdoor substations; the equipment is suitable for operation in high-altitude, high-temperature, high-humidity, dusty (sandstorm), and extremely low-temperature conditions.
2. Structural components (see image)
Elements located on the left (inclined/vertical): high-voltage bushings (insulating bushings) for connecting cables or overhead power lines.
Gray cylindrical tanks: separate compartments with SF6 gas, separated by flanges with yellow sealing rings; they demarcate the gas chambers of the circuit breaker, disconnector, and busbars.
Square cabinets above or beside the tanks: drive cabinets that control the opening and closing operations of switches and disconnectors.
Integrated steel base at the bottom: a single mounting base for the entire device, allowing pre-assembly at the factory and on-site installation as a complete assembled unit.
3. Functions: provides switching on, switching off, short-circuit protection, as well as grounding and creating a visible break in the circuit for maintenance work in 110 kV electrical networks; supports the automatic reclosing (AR) function; is used for power distribution, protection, and control at substations.
