GIS

　　1. Overview Gas-insulated metal-enclosed switchgear (abbreviated as GIS) has a history of over thirty years since its development in 1968. Since it incorporates all the main components such as circuit breakers, isolators, ground switches, busbars, instrument transformers, and arresters into a sealed metal container filled with insulating gas for insulation and arc extinguishing purposes, it offers advantages such as small size, low space requirement, immunity to external environmental influences, safe and reliable operation, simple maintenance, and a long service life. As a result, it is very popular among users and has seen rapid development; it is now widely used in various types of substations. 2. Performance features: Safe and reliable. All high-voltage components of the GIS are housed within sealed metal enclosures. The SF6 gas inside the enclosure serves not only as an internal insulating medium but also as an arc-quenching medium for the circuit breaker. The product poses no risk of electric shock, providing the operator with the highest level of safety and reducing the need for maintenance. It has strong environmental resistance. All the live components of GIS are enclosed within metal enclosures, so they are not affected by natural elements such as wind, frost, rain, and snow, nor by external contaminants or high altitudes; thus, it possesses excellent environmental resilience. High-quality inspections with minimal on-site workload; modern processing equipment is used, along with a comprehensive quality control system. All equipment is assembled and undergoes factory testing on-site at the plant. After testing, it is assembled into a transport unit, which facilitates transportation and on-site installation and reduces the amount of work required on site. Reliable electrical conductivity: The circuit conductors of the circuit breaker use self-acting contacts. This contact finger does not require external spring pressure; instead, its own elastic force ensures sufficient pressure on the conductive element, thus eliminating the risk of spring failure or loose contacts. The circuit breaker has a high electrical life (20 operations at full capacity and 2000 operations at the rated operating current). Due to low eddy current losses, the housings of almost all components in GIS are made of aluminum (with the exception of voltage transformers and arresters), which provides good corrosion resistance and **reduces eddy current losses. Excellent housing structure: The metal housing (cylinder) of the GIS is manufactured using a cold flanging process, which ensures that the welds of the two vertically intersecting cylinders are not on the same line of intersection; this greatly improves the electric field distribution and reduces the size of the structure. High insulation reliability