د تکنیکي پروپوزال: د هیبرید ګیس ایزولیشن پر مبنا ختمه CT وړاندیز لپاره د قابلیت اعتماد وړاندیز

Application Scenario:​​ Extreme cold regions (-40°C environment), environmentally stringent projects (e.g., Nordic wind power grid connection stations)

​Core Goal:​​ Enhance long-term reliability of Current Transformers (CTs) within Gas-Insulated Switchgear (GIS) while meeting low-carbon environmental requirements.

​I. Insulation Medium Optimization: SF₆/N₂ Hybrid Gas Technology​

• ​Parameter - Solution Design​
• ​Gas Ratio:​​ SF₆ (80%) + N₂ (20%) mixture
• ​Insulation Strength:​​ At 20°C & 0.5MPa, insulation strength ​>85% of pure SF₆
• ​Environmental Performance:​​ GWP (Global Warming Potential) reduced by 70%, significantly lowering greenhouse gas impact
• ​Low-Temperature Suitability:​​ Hybrid gas liquefaction point ≤ -60°C, ensuring ​no liquefaction risk​ at ​​-40°C​ in extreme cold environments

​II. Anti-Partial Discharge Shielding Design​

• ​Structural Innovation:​​
1. ​Epoxy Resin Casting:​​
• CT coils manufactured using vacuum casting process, epoxy resin filling rate >99.9%, eliminating internal voids.
2. ​Equipotential Metal Shielding Mesh:​​
• Zinc-plated copper mesh added to the outer layer of the casting body, maintained at equipotential to the CT primary conductor.
• Eliminates surface electric field distortion and suppresses partial discharge.
• ​Performance Validation:​​

• PD (Partial Discharge) level <5 pC (per IEC 60270 standard)
• Passed -40°C thermal cycling test, with no risk of insulation cracking.

​III. Dynamic Temperature Rise Control System​

• ​Intelligent Control Architecture:​​
  Sensor Layer → Control Layer → Execution Layer
  PT100 Temp Sensors → GIS Monitoring System → Fan Speed Control Module
• ​Function Implementation:​​
• ​Real-time Monitoring:​​ Built-in PT100 probes (±1°C accuracy) locate CT hotspot temperatures.
• ​Active Cooling:​​ Automatically activates GIS fan arrays when temperature rise exceeds threshold (e.g., ΔT >40K).
• ​Energy Efficiency Optimization:​​ Fan power dynamically adjusted based on demand, reducing wasted energy.

​IV. Key Technical Advantage Comparison​

​V. Scenario Adaptability Validation​

1. ​Extreme Cold Wind Power Scenario (Nordic):​​
• Passed -40°C /72h cold start test; CT ratio error ≤ ±0.2%.
• Optimized Pressure-Temperature curve for hybrid gas prevents excessive pressure drop at low temperatures.
2. ​Environmental Compliance:​​
• Complies with EU F-gas Regulation (No.517/2014) restrictions on SF₆ usage.
• Life cycle carbon footprint reduced by 52% (per ISO 14067 standard).

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