Open switchgear (air insulated switchgear? Abbreviated as AIS, it insulates the live part from the ground and the phase through air and insulators, and its bus bar is bare and directly in contact with air. The circuit breaker can be made of porcelain column or porcelain jar, and the porcelain sleeve is used as the equipment shell and external insulation, which is characterized by large external insulation distance and large area.
Gas-insulated switchgear (GIS for short) refers to a metal-enclosed switchgear that uses all or part of gas (generally SF6 gas as insulation medium), but does not use air at atmospheric pressure as insulation medium. Enclosed high-voltage electrical apparatus supported by high-quality epoxy resin insulator.
2. Different structures
According to the structure, GIS has the following types:
(1) phase separation formula. The main circuits are installed in independent metal cylindrical shells, supported by epoxy resin cast insulators and filled with SF6 gas.
(2) the main bus three-phase * * * tube. Only the three-phase main bus * * * adopts the shell, the three-phase bus is uniformly supported in the cylinder by insulators, and other components are of split-phase structure.
(3) All three-phase cylinders. The three phases of each module are installed in a cylindrical shell, supported and isolated by epoxy resin casting. The number of shells is small, the overall size is small, the sealing links are few, the shell current is small, but the interaction between phases is large.
(4) The mixed gas insulated switchgear is single-phase GIS, three-phase air insulated and no bus.
3. Different advantages
GIS is transported as a whole, with convenient installation, short period and low installation cost. The maintenance workload is small and the time is short. * * * Box GIS all adopts three-phase mechanical linkage, with low mechanical failure rate. Excellent breaking performance-The circuit breaker adopts a self-energy arc extinguishing chamber (a mixed structure of self-energy thermal expansion and auxiliary air compressor) based on the new arc extinguishing principle, which makes full use of the energy of the arc itself.
AIS？ Cheaper price, convenient installation and testing, good flexibility and convenient maintenance and expansion.
References:
Baidu Encyclopedia-Geographic Information System
Baidu Encyclopedia-Artificial Intelligence System