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The size of gas insulated substation is significantly small compared to conventional substation because of
High electronegative property of SF6тАЛ gas
High dielectric property of SF6тАЛ gas
High insulation property of SF6тАЛ gas
All of above
All of above
Gas Insulated Substations (GIS) utilize Sulfur Hexafluoride (SF6тАЛ) as the primary dielectric medium, which possesses superior insulation and arc-quenching properties compared to air. These properties allow for a much smaller clearance between high-voltage live parts and grounded enclosures, significantly reducing the overall physical footprint.
Gas Insulated Substations (GIS) utilize Sulfur Hexafluoride (SF6тАЛ) as the primary dielectric medium, which possesses superior insulation and arc-quenching properties compared to air. These properties allow for a much smaller clearance between high-voltage live parts and grounded enclosures, significantly reducing the overall physical footprint.
EbтАЛтЙИ3├ЧEairтАЛ тАФ SF6тАЛ breakdown strength relative to air
d=EdielectricтАЛVтАЛ тАФ clearance distance required for voltage V
SF6тАЛ is a highly electronegative gas; its molecules have a strong affinity for free electrons. When an electrical discharge initiates, SF6тАЛ captures these electrons to form negative ions, effectively preventing the development of an avalanche breakdown. Consequently, the breakdown strength of SF6тАЛ is approximately 2.5 to 3 times higher than that of air at atmospheric pressure.
GIS occupies roughly 10% of the land area required for a conventional Air Insulated Substation (AIS).
SF6тАЛ is chemically inert, non-toxic, and non-flammable under normal operating conditions.
The modular design of GIS allows for enclosure in sealed, grounded metallic tanks.
Extremely compact size
High reliability due to immunity from environmental factors like pollution and humidity
Low maintenance requirements
High initial cost
SF6тАЛ is a potent greenhouse gas requiring strict handling and sealing
Complexity in gas management and leak detection
Urban substations with limited land availability
Offshore wind farms
Underground substations
| Feature | AIS | GIS |
|---|---|---|
Insulation Medium | Air (AIS) | SF6тАЛ Gas (GIS) |
Footprint | Large | Compact |
Option A (Electronegativity) explains the mechanism of electron capture.
Option B (Dielectric strength) relates to the voltage withstand capability.
Option C (Insulation property) is the practical outcome of the previous two traits.
All options collectively contribute to the compact design characteristic of GIS.
D is correct тАФ The synergistic effect of SF6тАЛ being highly electronegative and having superior dielectric properties allows for reduced insulation clearances, resulting in a significantly smaller substation footprint.
Always remember that SF6тАЛ performance is pressure-dependent; as gas pressure increases, the dielectric strength improves, allowing even further reductions in equipment size.