The SUT 220kV class oil-immersed power transformer series is designed for high-voltage power transformation in substations, power plants, renewable energy facilities and large industrial applications.

Advanced simulation software is used to analyze electrical, magnetic, thermal and mechanical conditions, helping optimize the transformer structure and safety factors. The resulting design focuses on low losses, low noise, low temperature rise, high reliability and leak-proof operation.

The transformer is manufactured in controlled production environments using mature manufacturing processes and intelligent production equipment. The series covers multiple insulation levels, frequencies and specialized configurations for generator step-up, start-up and standby, tie and testing transformer applications.

01. Advanced Structural Optimization

Advanced simulation analysis of electrical, magnetic, thermal and mechanical conditions is used to optimize transformer structure and improve design reliability.

02. Six-Step Step-Lap Core

The core adopts six-step full-miter step-lap stacking with a reinforced steel clamping structure to support mechanical stability and reduce no-load losses.

03. Precision Winding Process

Coils are wound using a vertical winding machine and pneumatic tensioning system. Controlled drying and hydraulic compression help maintain the designed coil geometry.

04. High Mechanical Strength

The active part is reinforced with steel tie bars, upper beams and side beams to improve mechanical strength and short-circuit withstand capability.

05. Leak-Proof Tank Design

The transformer tank uses an integral manufacturing process with structural analysis and automatic submerged arc welding to achieve reliable sealing performance.

06. Reliable & Energy-Efficient Operation

Designed for low losses, low noise, low temperature rise, low partial discharge and reliable long-term operation.

full range of products including various insulation levels, various frequencies, generator main transformers, start-up/standby transformers, tie transformers, and testing transformers.

Product Configurations

Generator Step-Up Transformers

For power generation facilities requiring high-voltage transformation.

Start-Up & Standby Transformers

Designed for auxiliary power and start-up systems.

Tie Transformers

For interconnection between different voltage levels or power systems.

Testing Transformers

For applications requiring specialized high-voltage testing configurations.

Multiple Insulation Levels & Frequencies

Configurations are available according to the specific electrical design and project requirements.

Core Design

The core adopts six-step full-miter step-lap stacking with high-grade grain-oriented silicon steel.

Coil Manufacturing

Coils are wound using vertical winding equipment and pneumatic tensioning to achieve consistent winding quality.

Coil Drying

Vacuum/kerosene vapor-phase drying processes are used according to the production process to achieve thorough drying of the windings.

Hydraulic Compression

A 200-ton hydraulic press is used to compress the coils and help maintain the designed axial dimensions.

Clean-Room Assembly

Active-part assembly is performed in a controlled clean-room environment, with core-limb verticality measured before coil assembly to maintain proper concentricity.

Tank Manufacturing

The tank is manufactured using integral pre-assembly, 3D structural analysis and automatic submerged arc welding, followed by leakage testing and surface treatment.

Power Plants

For generator step-up and other high-voltage transformation applications in power generation facilities.

Substations

For high-voltage transformation and grid power distribution systems.

Solar & Wind Power

Suitable for renewable energy booster substations and large-scale photovoltaic and wind power projects.

Mining & Petrochemical

For large industrial enterprises including mining operations and petrochemical facilities.

SUT provides project-specific 220kV transformer configurations according to electrical requirements, insulation levels, frequency, rated capacity, voltage combination and transformer application.

Possible Configuration Areas

Rated Capacity

Voltage Combination

Insulation Level

Frequency

Tap-Changer Configuration

Transformer Application

What is a 220kV oil-immersed power transformer?

A 220kV oil-immersed power transformer is designed to transform electrical energy between high-voltage levels in substations, power plants and other large-scale power systems.

What rated capacities are available?

The current product information includes 120,000 kVA, 150,000 kVA and 240,000 kVA configurations. Availability depends on the specific transformer design.

What is the voltage rating?

The high-voltage side is rated at 220 kV for the listed configurations.

What is the tap range?

The listed SZ22, SZ20 and SZ18 configurations use a tap range of ±8 × 1.25%.

What applications are suitable for 220kV transformers?

Typical applications include power plants, substations, solar and wind power facilities, mining operations and petrochemical industrial facilities.

Can SUT customize 220kV transformers?

Yes. Transformer configurations can be developed according to project-specific capacity, voltage, insulation, frequency, tap-changing and application requirements.

Are generator step-up transformers available?

Yes. The current 220kV series description includes generator main transformers, as well as start-up/standby, tie and testing transformer configurations.

What standards are supported?

The current product page states that the transformer series is compliant with IEC international standards.