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Meta Description: This article provides a detailed comparison between dry-type transformers and oil-immersed transformers in terms of insulation methods, safety, maintenance costs, and applicable scenarios, helping you make the optimal equipment selection based on actual needs.
Main Content
In power distribution system design, transformer selection is a critical. The two mainstream types of transformers currently on the market—dry-type transformers and oil-immersed transformers—each have their own technical characteristics and applicable scenarios. This article will provide an in-depth analysis of their differences and offer practical selection suggestions.
1. Core Differences Comparison
| Comparison Dimension | Dry-Type Transformer | Oil-Immersed Transformer |
|---|---|---|
| Insulation Medium | Air/Epoxy Resin | Mineral Oil or Synthetic Oil |
| Fire Resistance | Excellent flame retardancy, no fire risk (F1 Class) | Combustible oil, potential explosion risk |
| Environmental Friendliness | No oil pollution, recyclable materials | Potential oil leakage polluting soil and water sources |
| Maintenance Requirements | Only requires regular dust removal, maintenance-free design | Regular checks of oil level and quality, replacement of oil filters and seals |
| Installation Requirements | No oil pit needed, can be installed directly near load centers | Requires oil pits and explosion-proof facilities |
| Overload Capacity | Strong (Class H insulation, withstands 180°C) | Relatively weak |
| Efficiency | High (SCB18 no-load loss is 30%+ lower than oil-immersed) | Relatively low |
| Cost | High initial investment, low operating costs | Low initial investment, high maintenance and operating costs |
2. Prominent Advantages of Dry-Type Transformers
- Safety and Reliability
- Oil-free design completely eliminates fire hazards, passes 950°C flame test (F1 certification).
- IP23 protection allows outdoor installation, resistant to harsh environments like moisture and dust.
- Smart Maintenance
- Integrated temperature monitoring and partial discharge detection interfaces, supports IoT remote monitoring.
- Enables predictive maintenance, reducing unexpected downtime losses.
- Energy Efficiency and Environmental Protection
- SCB18 series no-load loss as low as 0.29W/kVA (1000kVA specification), meets national Level 1 energy efficiency.
- Operating noise <55dB, suitable for noise-sensitive areas.
3. Applicable Scenarios for Oil-Immersed Transformers
Despite the obvious advantages of dry-type transformers, oil-immersed transformers are still irreplaceable in the following scenarios:
- Extra-Large Capacity Requirements: Projects with voltage levels of 110kV and above and capacities exceeding 50MVA;
- Cost-Sensitive Scenarios: Rural grid renovations with limited initial investment budgets;
- Special Environments: High-altitude, extremely cold areas (oil-immersed transformers offer more stable heat dissipation).
4. Key Factors for Selection Decisions
- Safety Priority
- Densely populated places (subways, hospitals, commercial centers) must use dry-type transformers.
- Total Cost of Ownership (TCO)
- Dry-Type Transformers: High initial cost but lower comprehensive cost over 10 years (energy savings + maintenance-free).
- Oil-Immersed Transformers: Low initial cost but higher long-term maintenance and electricity expenses.
- Policies and Regulations
- Green building certifications (LEED/BREEAM) require the use of dry-type transformers;
- Some regions have strict restrictions on the installation of oil-immersed transformers.
5. Recommended Typical Application Scenarios
- Preferred Scenarios for Dry-Type Transformers:
✅ Data Centers ✅ High-Rise Buildings ✅ Chemical Plants ✅ Rail Transit ✅ New Energy Power Stations - Applicable Scenarios for Oil-Immersed Transformers:
✅ Field Substations ✅ Rural Power Grids ✅ Large Power Plants ✅ Temporary Construction Power Supply
Conclusion
There is no absolute advantage or disadvantage between dry-type transformers and oil-immersed transformers; the key lies in their suitability for the application scenario. With technological advancements, the advantages of dry-type transformers in efficiency, intelligence, and safety are becoming increasingly prominent, making them the preferred choice for modern power distribution systems. It is recommended that users consider safety requirements, lifecycle costs, and policy directions when making selections to choose the most suitable technical solution.