SF₆-Free GIS Voltage Transformer Solution Based on Eco-Friendly Gas Mixtures
Ⅰ. Background and Challenges
- Policy-Driven Transformation
SF₆ gas has a Global Warming Potential (GWP) 23,500 times that of CO₂. It faces global restriction policies like the EU’s F-Gas Regulation and China’s Non-CO₂ Greenhouse Gas Control Plan. - Industry Pain Points
Traditional GIS voltage transformers rely on SF₆ insulation, posing gas leakage risks. Their lifecycle carbon footprint exceeds 85% of the equipment’s total emissions.
II. Core Solution
Eco-Friendly Dielectric Replacement Technology
|
Dielectric Type |
GWP Value |
Insulation Strength (vs SF₆) |
Application Scenario |
|
Dry Air/N₂ Mixture |
≈0 |
30% |
Medium-voltage systems ≤110kV |
|
C₅-PFK (Perfluorinated pentanone) |
<1 |
90% |
High-voltage systems 220kV |
|
Gas Mixture Formula |
GWP<1 |
Equivalent to SF₆ |
Full voltage range coverage |
Note: Optimizing gas ratios (e.g., 4% C₅-PFK + 96% Dry Air) balances insulation strength and environmental performance.
Certification Assurance
Certified to IEC 62271-203:2011 (C2M2-level sealing) and GB/T 11022-2020, ensuring a sealing lifespan ≥30 years.
III. Quantified Benefits Analysis
- Carbon Reduction Benefits
Greenhouse Gas Emission Intensity: 0.02 tCO₂e/unit-year (98% reduction vs conventional equipment)
Lifecycle Carbon Footprint: Reduced by 5,200 tCO₂e per 100 units (over 30-year lifespan) - Economic Benefits
|
Cost Item |
Conventional Equipment |
This Solution |
Reduction |
|
Gas Procurement Cost |
$18,000 |
$2,500 |
86% ↓ |
|
Leakage Maintenance |
$7,500 |
$300 |
96% ↓ |
|
Carbon Tax Expenditure |
$12,000 |
$0 |
100% ↓ |
|
Total Cost of Ownership |
$375,000 |
$300,000 |
20% ↓ |
IV. Engineering Application Case
China Southern Grid’s Zhuhai Hengqin Project (2024 Commissioning):
• Equipment: HGIS-252kV environmentally friendly voltage transformer
• Operational Data:
Annual Leakage Rate: 0.08% (below IEC limit of 0.5%)
Partial Discharge: ≤3 pC (IEC 60044 limit: ≤10 pC)
Insulation Aging Rate: Reduced by 40% (humidity control <50ppm)
V. Technology Evolution Path
- Gas Mixture Optimization: Developing novel CF₃SO₂F/CO₂ blends (GWP≈0.3, insulation strength reaches 95% of SF₆).
- Solid Insulation Technology: R&D on EPDM rubber-base vacuum-cast insulators (pilot voltage level: 145kV).
