Dry-Type Transformers vs. Oil-Immersed Transformers: Selecting the Optimal Solution Based on Project Requirements

I. Key Decision Factors Comparison

1. Safety Performance Matrix
   • Dry-Type Transformers:
     ✓ Oil-free design certified to UL 94 V-0 flame resistance
     ✓ Can be installed directly in crowded areas (e.g., subway stations)
   • Oil-Immersed Transformers:
     × Require oil containment pits and fire protection systems
     × Risk of combustion during faults (ignition point ≥300°C)
2. Total Cost of Ownership Analysis (Example: 2000kVA)
   Cost Type Dry-Type Transformer Oil-Immersed Transformer
   Initial Purchase. ¥680,000. ¥580,000
   10-Year Energy ¥1,200,000. ¥1,500,000
   Maintenance ¥50,000 ¥180,000
   Total TCO ¥1,930,000 ¥2,260,000

II. Selection Guide for Typical Scenarios

1. Mandatory Dry-Type Applications
   • Underground substations (compliant with GB 50053 explosion-proof requirements)
   • Data centers (mandatory for Tier III+ certification)
   • Offshore wind platforms (salt spray corrosion environments)
2. Areas Where Oil-Immersed Still Excels
   • Extra-high voltage transmission (500kV+)
   • Extreme cold regions (-45°C and below)
   • Metallurgical industries requiring frequent overloads

III. Emerging Technology Trends

1. Smart Upgrades for Dry-Type Transformers
   • Integrated partial discharge monitoring (sensitivity ≤5pC)
   • Digital twin systems (92% lifespan prediction accuracy)
2. Eco-Improvements for Oil-Immersed Transformers
   • Biodegradable vegetable insulating oil (ignition point raised to 350°C)
   • Fully sealed designs (maintenance-free cycle extended to 15 years)

Engineering Decision Tree:

1. Is the location densely populated? → Choose dry-type
2. Is Tier 1 efficiency required? → Select SCB18 dry-type
3. Is budget limited and environment low-risk? → Consider oil-immersed

Industry Data Support:

• Dry-type transformers now hold 58% global market share (Wood Mackenzie 2024)
• China’s SCB18 dry-type purchases growing 23% annually (CEC data)