Key Technical Analysis of Winding Materials for Oil-Immersed Transformers

I. Core Influence of Winding Materials on Oil-Immersed Transformer Performance

1. Critical Electrical Performance Determinants

• Conductivity of oil-immersed transformer windings directly impacts efficiency (99.99% oxygen-free copper reduces losses by 15%)
• Insulation performance determines voltage withstand level (up to 220kV maximum)
• Material temperature coefficient affects temperature rise control (every 0.001/℃ reduction extends lifespan by 10%)

2. Mechanical Reliability Assurance

• Tensile strength requirement ≥200MPa (withstanding 25× rated current impact)
• Elongation requirement >30% (ensuring deformation resistance)
• Surface roughness Ra<0.8μm (reducing partial discharge risks)

II. Premium Material Selection Standards for Oil-Immersed Transformers

1. Conductor Material Selection

• TU1 oxygen-free copper preferred for oil-immersed transformers (purity>99.99%)
• Electrolytic copper foil recommended for high-voltage oil-immersed transformers (thickness tolerance ±0.005mm)
• Copper-silver alloy considered for special environment oil-immersed transformers (3× improved corrosion resistance)

2. Insulation System Configuration

• Triple insulation required for oil-immersed transformer windings (enamel+paper+oil gap)
• Class H insulation materials for high-temperature oil-immersed transformers (180℃ rating)
• Plant-ester compatible insulation varnish recommended for eco-friendly oil-immersed transformers

III. Hazards of Inferior Windings to Oil-Immersed Transformers

1. Efficiency Loss Issues

• Impure windings increase oil-immersed transformer losses by 20-30%
• Uneven cross-sections cause excessive local temperature rise (hotspot differential >15K)
• Insulation defects lead to 50% increase in no-load current

2. Safety Risks

• Inferior windings reduce short-circuit withstand capability by 40%
• Accelerate insulation oil aging in oil-immersed transformers (3× faster acid value increase)
• Increase fire risks in oil-immersed transformers (30-50℃ lower flash point)

IV. Advanced Winding Technologies for Oil-Immersed Transformers

1. Intelligent Manufacturing Processes

• Automatic winding alignment system (±0.1mm precision)
• Online insulation detection technology (100% enamel integrity inspection)
• Vacuum pressure impregnation process (30% improved insulation strength)

2. New Material Applications

• Nanocrystalline strips (20% reduced iron losses)
• High-temperature superconducting windings (3× increased capacity density)
• Graphene-enhanced conductors (15% size reduction)

V. Inspection Standards for Oil-Immersed Transformer Windings

1. Factory Test Items

• DC winding resistance test (<2% three-phase imbalance)
• Partial discharge measurement (<10pC@1.5Ur)
• Sudden short-circuit test (verifying mechanical strength)

2. Operational Monitoring Indicators

• Winding hotspot temperature (<95℃ optimal)
• Frequency response analysis for winding deformation (<3% frequency difference)
• Dissolved gas analysis for winding fault diagnosis (C2H2<0.1ppm)

VI. Selection Recommendations for Oil-Immersed Transformer Windings

1. Technical Parameter Confirmation

• Clarify oil-immersed transformer load characteristics (continuous/impulse)
• Confirm operating environment (altitude, humidity, etc.)
• Evaluate lifespan requirements (20/30 years)

2. Supplier Evaluation Points

• Material traceability capability
• Completeness of process control documents
• Operational case studies of similar oil-immersed transformers

VII. Future Trends for Oil-Immersed Transformer Windings

1. Intelligent Development Direction

• Embedded fiber optic temperature monitoring
• AI-based winding health diagnosis systems
• Digital twin winding condition prediction

2. Eco-Innovation Paths

• Biodegradable insulation materials
• Heavy-metal-free winding processes
• Low-carbon manufacturing technologies

Conclusion:
The selection and quality control of winding materials directly impact the full lifecycle performance of oil-immersed transformers. We recommend users:

1. Prioritize IEC 60076 certified oil-immersed transformer products
2. Establish specialized winding inspection systems (especially first 3 years)
3. Cooperate with professional manufacturers for customized solutions
4. Conduct regular condition assessments of windings

Through scientific selection and meticulous maintenance, oil-immersed transformer windings can maintain optimal working conditions, providing reliable protection for power systems.