220kV Outdoor Oil-Immersed Power Transformer (31.5MVA–400MVA)

The 220kV Outdoor Oil-Immersed Power Transformer is designed for high-voltage transmission and distribution systems in utility substations, industrial power networks, renewable energy projects, and large-scale infrastructure facilities. Rated from 31,500kVA to 400,000kVA, this transformer delivers stable power transmission, low energy losses, and reliable long-term operation under demanding outdoor conditions.

Built with advanced core materials, optimized winding structures, and efficient oil circulation cooling systems, the transformer ensures excellent voltage regulation, high short-circuit withstand capability, and extended service life. It complies with international standards such as IEC, IEEE, and GB requirements.

Product Features

High Transmission Efficiency

The transformer adopts high-grade grain-oriented silicon steel cores with step-lap construction, effectively reducing no-load losses, noise levels, and magnetic flux leakage.

Reliable Insulation System

A carefully designed oil-paper insulation structure provides excellent dielectric strength and thermal stability, ensuring safe operation under high-voltage conditions.

Strong Short-Circuit Resistance

Optimized winding arrangements and reinforced clamping structures improve mechanical strength and enhance resistance to short-circuit impacts.

Efficient Cooling Performance

Depending on project requirements, cooling methods such as ONAN, ONAF, OFAF, or OFWF can be provided, ensuring stable temperature rise control during continuous operation.

Outdoor Environmental Adaptability

The transformer tank, radiators, conservator, and accessories are treated with anti-corrosion coatings, making the unit suitable for harsh climates including coastal, desert, tropical, and high-altitude regions.

Long Service Life

High-quality insulating oil, vacuum drying technology, and strict manufacturing processes contribute to a service life exceeding 30 years under normal operating conditions.

Product Structure

The transformer mainly consists of:

• High-permeability silicon steel core
• High-voltage winding
• Low-voltage winding
• Transformer oil tank
• Cooling radiators
• Conservator tank
• Buchholz relay
• Oil level indicator
• Pressure relief device
• HV and LV bushings
• On-load tap changer (OLTC) or off-circuit tap changer
• Monitoring and protection devices

Technical Specifications

Applications

The 220kV oil-immersed transformer is widely used in:

• National transmission and distribution networks
• Utility substations
• Thermal power plants
• Hydroelectric stations
• Wind power projects
• Solar energy farms
• Mining operations
• Metallurgical industries
• Petrochemical facilities
• Large industrial parks

FAQ

1. What cooling methods are available for 220kV transformers?

Common cooling methods include ONAN, ONAF, OFAF, and OFWF. The selection depends on transformer capacity, operating conditions, and project requirements.

2. Can the transformer be customized for different grid standards?

Yes. Voltage ratio, vector group, impedance, cooling system, tap changer type, and protection devices can all be customized.

3. What is the expected service life?

With proper maintenance and operating conditions, the transformer can provide reliable service for more than 30 years.

4. What tests are performed before delivery?

All transformers undergo routine, type, and special tests according to IEC or customer specifications to ensure safety and performance.

Request a Quote

Looking for a reliable 220kV Outdoor Oil-Immersed Power Transformer (31.5MVA–400MVA) for your transmission or substation project?

Contact us with your required voltage, capacity, cooling method, and installation conditions. Our engineering team will provide a customized solution, technical proposal, and competitive quotation tailored to your project needs.