Oil Immersed Transformer
Oil Immersed Transformer Manufacturer for Global Power Distribution Projects
Reliable Oil Immersed Transformers for Utility, Industrial and Renewable Energy Applications
Oil immersed transformers are widely used in medium-voltage power distribution systems because of their reliable operation, efficient cooling capability, and long service life. By using insulating oil as both an electrical insulation medium and a cooling medium, these transformers provide stable performance for utility networks, industrial facilities, renewable energy projects, and infrastructure developments.
For global distributors, EPC contractors, utilities, and industrial procurement teams, choosing a transformer supplier requires more than comparing specifications and prices. Buyers need confidence in manufacturing capability, quality consistency, technical support, documentation, and long-term supply reliability.
Our oil immersed transformers are designed and manufactured according to international transformer engineering practices, including IEC 60076 and IEEE C57 standards where applicable. Each unit is tested before shipment to verify electrical performance, insulation reliability, and compliance with customer requirements.
Technical Specifications Overview
|
Parameter |
Standard Range |
Custom Options |
|
Rated Capacity |
10 kVA – 5000 kVA |
Higher capacity designs available |
|
Primary Voltage |
Up to 36 kV |
Customized voltage levels |
|
Secondary Voltage |
Low voltage distribution outputs |
Dual voltage options |
|
Frequency |
50 Hz / 60 Hz |
Special frequency designs |
|
Cooling Method |
ONAN |
ONAF available |
|
Winding Material |
Copper / Aluminum |
Customized winding solutions |
|
Insulation Fluid |
Mineral Oil |
Natural or synthetic ester fluid |
|
Vector Group |
Dyn11, Yyn0, Dyn1 and others |
Custom configurations |
|
Tap Changer |
OCTC |
OLTC available |
|
Installation |
Indoor / Outdoor |
High altitude, coastal, and low-temperature designs |
Complete Oil Immersed Transformer Product Range
We manufacture transformer solutions for different power distribution applications:
Oil Filled Distribution Transformers
Pole Mounted Transformers
Pad Mounted Transformers
Single Phase Distribution Transformers
Three Phase Distribution Transformers
Step-Up and Step-Down Transformers
Renewable Energy Transformers
Industrial Power Distribution Transformers
OEM and Custom Engineered Transformers
Why Global Buyers Select Oil Immersed Transformers
Efficient Cooling and Long-Term Reliability
Transformer oil transfers heat generated by the core and windings to the external tank surface, providing effective thermal management during continuous operation.
Maintaining stable operating temperatures helps reduce insulation aging, which is one of the main factors affecting transformer lifespan. With proper installation and maintenance, oil immersed transformers are designed for decades of reliable service.
Stable Insulation Performance
The active components are immersed in insulating oil, creating a stable dielectric environment that helps protect internal components from moisture, dust, and environmental contamination.
Sealed tank construction and suitable protective coatings improve durability for outdoor applications, including high-humidity and coastal environments.
Lower Energy Loss and Operating Cost
High-quality CRGO silicon steel cores and optimized winding designs help reduce no-load and load losses. Improved efficiency allows utilities and industrial users to lower lifetime operating costs.
Mechanical Strength Under Electrical Stress
During short-circuit conditions, transformer windings experience strong electromagnetic forces. Reinforced winding structures, controlled clamping systems, and precise manufacturing processes improve mechanical stability and operational reliability.
Manufacturing Capability and Production Process
Reliable transformer performance depends on controlled manufacturing and inspection processes.
Core and Coil Manufacturing
CRGO silicon steel cores are precisely cut and stacked to reduce magnetic losses and vibration. Professional winding equipment ensures accurate dimensions, consistent tension, and uniform insulation spacing.
Vacuum Drying and Oil Filling
Transformer active parts undergo vacuum drying to remove moisture from cellulose insulation materials. Degassed insulating oil is then filled under vacuum conditions to minimize air bubbles and improve dielectric performance.
Tank Fabrication and Protection
Transformer tanks are manufactured through controlled welding, surface treatment, protective coating, and leakage testing processes to ensure durability during transportation and long-term outdoor operation.
Quality Control, Testing and Documentation
Quality assurance is integrated throughout production.
Quality Management
Manufacturing processes are supported by:
ISO 9001 Quality Management System
ISO 14001 Environmental Management System
ISO 45001 Occupational Health and Safety Management System
Routine Factory Testing
Every transformer undergoes testing before dispatch, including:
Voltage Ratio Test
Winding Resistance Test
No-Load Loss and Current Test
Load Loss and Impedance Test
Applied Voltage Test
Induced Voltage Test
Insulation Resistance Test
Oil Dielectric Breakdown Voltage Test
Tank Leakage Test
Accessory Inspection
For utility and EPC projects, Factory Acceptance Testing (FAT), third-party inspection, and additional type test documentation can be provided according to project requirements.
Manufacturing Capability for Global Supply
With dedicated transformer production facilities, professional engineering support, and complete testing capability, we support standard production, customized projects, and long-term OEM cooperation.
Our manufacturing support includes:
Batch production for distributors
Engineering evaluation before production
Complete technical documentation
Factory test reports
Export-standard transportation packaging
Support for repeat and long-term supply programs
For qualified projects, customers can request technical drawings, inspection records, and project documentation to support procurement approval.
Custom Transformer Solutions for International Projects
Different regions require different electrical configurations and environmental adaptations.
We provide customization for:
Capacity and voltage requirements
Vector groups
Tap changer configurations
Terminal arrangements
High-altitude applications
Coastal and anti-corrosion protection
Low-temperature environments
Renewable energy integration
OEM nameplates and documentation
Customers can provide technical specifications, single-line diagrams (SLD), drawings, or tender documents for engineering evaluation.
Applications and Project Fields
Oil immersed transformers are widely used in:
Utility distribution networks
Solar and wind power projects
Industrial manufacturing plants
Commercial power systems
Mining operations
Infrastructure developments
Rural electrification programs
Substations and grid expansion projects
Why Work With Us as Your Transformer Supplier
Global buyers evaluate suppliers based on reliability, technical capability, and long-term cooperation potential.
We support customers through:
Consistent manufacturing quality
Flexible OEM and distributor cooperation
Technical assistance during project evaluation
Complete testing documentation
Export packaging solutions
Responsive communication throughout production
Support for repeat orders and long-term supply agreements
Our engineering team works with distributors, EPC contractors, and industrial users to provide suitable transformer solutions from initial specification review through final delivery.
Frequently Asked Questions
Request a Customized Transformer Solution
Whether you are a distributor, EPC contractor, utility company, or industrial buyer, our engineering team can support your transformer requirements with technical recommendations, customized designs, and complete documentation.
Send your specifications, drawings, or tender requirements to receive a professional transformer proposal and quotation.
Transpower Electrical Equipment Co., Ltd. is one of the most professional oil immersed transformer manufacturers and suppliers in China, specialized in providing high quality customized service. We warmly welcome you to buy oil immersed transformer for sale here and get quotation from our factory. For price consultation, contact us.