SF₆-Free GIS Voltage Transformer Solution Based on Eco-Friendly Gas Mixtures

Ⅰ. Background and Challenges

1. 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.

2. 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 &ge;30 years.

III. Quantified Benefits Analysis

1. 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)

2. Economic Benefits

Cost Item

Conventional Equipment

This Solution

Reduction

Gas Procurement Cost

$18,000

$2,500

86% &darr;

Leakage Maintenance

$7,500

$300

96% &darr;

Carbon Tax Expenditure

$12,000

$0

100% &darr;

Total Cost of Ownership

$375,000

$300,000

20% &darr;

IV. Engineering Application Case
China Southern Grid&rsquo;s Zhuhai Hengqin Project (2024 Commissioning):
&bull; Equipment: HGIS-252kV environmentally friendly voltage transformer
&bull; Operational Data:
Annual Leakage Rate: 0.08% (below IEC limit of 0.5%)
Partial Discharge: &le;3 pC (IEC 60044 limit: &le;10 pC)
Insulation Aging Rate: Reduced by 40% (humidity control <50ppm)

V. Technology Evolution Path

1. Gas Mixture Optimization: Developing novel CF₃SO₂F/CO₂ blends (GWP&asymp;0.3, insulation strength reaches 95% of SF₆).

2. Solid Insulation Technology: R&D on EPDM rubber-base vacuum-cast insulators (pilot voltage level: 145kV).