Core Advantages of Oil-Immersed Transformers: Performance and Reliability

Oil-immersed transformers play a vital role in modern power systems, offering excellent performance, durability, and adaptability. With reliable heat dissipation, high insulation, and robust design, these transformers ensure stable and long-lasting operation in various environments.

Excellent Heat Dissipation

Oil-immersed transformers use mineral oil or synthetic ester with high specific heat capacity and insulation properties. This enables efficient heat absorption from the core and windings, dissipated through radiators or coolers. They can handle short-term overloads better than dry-type transformers and minimize insulation aging, ensuring continuous power supply under heavy loads.

Superior Insulation and Withstand Voltage

Transformer oil with a breakdown voltage ≥30kV/2.5mm provides high insulation, fills internal air gaps, and suppresses partial discharges. A sealed tank with optional nitrogen padding prevents oxygen and moisture intrusion, greatly extending service life.

Reliable Protection Systems

Gas decomposition from minor faults triggers gas relays with light alarm and heavy trip signals. Additional safety devices like pressure relief valves, oil level gauges, and thermometers enhance fault detection. With regular maintenance, oil-immersed transformers offer over 30 years of service and can be rejuvenated through oil treatment.

Strong Environmental Adaptability

The sealed, corrosion-resistant tank structure resists moisture, dust, and salt spray. Low-freezing-point oil (-45°C) ensures operation in cold climates, while enhanced oil circulation provides cooling in hot regions, enabling stable performance in all weather conditions.

Economic and Low Maintenance

Oil-immersed transformers are compact and cost-effective for large-capacity applications, especially above 10MVA. Advanced diagnostic tools like DGA (Dissolved Gas Analysis) and furfural testing accurately assess insulation health, extending maintenance intervals up to 10 years.

Application Scenarios

Power Grid Infrastructure

Used as main transformers in substations (110kV and above) and export transformers in power plants, oil-immersed transformers support high-voltage transmission. In UHVDC projects (±800kV and above), they enable cross-regional electricity transfer with remote monitoring and intelligent control systems.

Industrial Power Systems

In heavy industries like metallurgy and petrochemicals, oil-immersed transformers guarantee uninterrupted power. Steel smelting requires high overload capacity, met by forced oil-air cooling systems. For refineries and coal chemical plants, sealed explosion-proof designs ensure reliable power under harsh and hazardous conditions.

Renewable Energy Projects

Oil-immersed transformers are vital for wind and solar power. In wind farms, they step up turbine voltage for grid connection, operating efficiently in remote and cold environments. In photovoltaic power plants, they transform low-voltage DC into high-voltage AC for long-distance transmission. For offshore wind, their corrosion-resistant design makes them ideal for moist, salty conditions.