Short Answer:
A Gas Insulated Substation (GIS) is a compact substation where major components like busbars, circuit breakers, and isolators are enclosed in metal containers filled with SF₆ gas. This gas acts as an excellent insulator and arc extinguisher.
GIS is ideal for urban, industrial, and space-limited areas due to its small size, high reliability, and low maintenance. It offers high safety and environmental protection compared to air-insulated substations.
Detailed Explanation:
Gas Insulated Substation (GIS)
GIS is a type of substation where the entire system is enclosed in sealed metal containers filled with sulfur hexafluoride (SF₆) gas, which has high dielectric strength.
Key features:
- Compact: Requires less space than AIS.
- Sealed: Protects equipment from dust, pollution, and moisture.
- Reliable: Less affected by environmental conditions.
- Safe: Explosion risk is minimized.
Major components include:
- Circuit breakers
- Isolators
- Current transformers
- Voltage transformers
- Busbars
Applications:
- Densely populated cities
- Underground or rooftop substations
- Areas with harsh weather
Conclusion:
A GIS is a sealed, compact, and safe substation that uses SF₆ gas for insulation. It is best suited for urban areas, offering high reliability and reduced maintenance. Its advantages make it ideal where space and safety are major concerns.