Gas-insulated substations (GIS) are electrical substations that use sulfur hexafluoride (SF6) gas as the insulating medium for high-voltage components such as circuit breakers, disconnectors, and transformers. SF6 gas provides excellent electrical insulation and arc-quenching properties, making it suitable for high-voltage applications.
Gas-insulated substations (GIS) can be classified into different types based on various factors. Here are some common types of gas-insulated substations:
- Single Busbar GIS: In this type of GIS, a single busbar is used for both incoming and outgoing connections. It is a simple and cost-effective solution suitable for small to medium-sized substations.
- Double Busbar GIS: Double busbar GIS consists of two separate busbars, one for incoming connections and the other for outgoing connections. This configuration provides redundancy and flexibility for maintenance and expansion. It is commonly used in medium to large-sized substations.
- Ring Main Unit (RMU): RMU is a compact type of GIS that is used for distribution networks in urban areas or industrial applications. It typically includes a combination of a circuit breaker, load break switch, and a switch-fuse combination. RMUs are commonly used in compact substations or as secondary substations.
- Multi-Bay GIS: Multi-bay GIS consists of multiple bays, where each bay contains the necessary components such as circuit breakers, disconnectors, and transformers. It allows for modular expansion and flexibility in system configuration.
- Hybrid GIS: Hybrid GIS combines gas-insulated switchgear with other technologies, such as air-insulated switchgear or solid-insulated switchgear. It is used in situations where a combination of different insulation technologies is required to optimize the performance or meet specific requirements of the substation.
- Mobile Substations: Mobile GIS substations are self-contained units that can be easily transported and deployed as temporary or emergency solutions. They are often used in situations where a quick and temporary power supply is needed, such as during construction projects or in disaster-stricken areas