230kV 3-Phase Step-Down Power Transformer
The 230kV 3-Phase Step-Down Power Transformer is designed to reduce high transmission voltages to suitable distribution levels while maintaining excellent efficiency and operational stability. Engineered for utility substations and large-scale grid interfaces, this transformer ensures safe and controlled power delivery from high-voltage networks to regional or industrial distribution systems. Its oil-immersed insulation system provides strong dielectric protection and efficient thermal dissipation, enabling reliable continuous operation under varying load conditions. Precision core construction and optimized winding layout help minimize energy losses and voltage fluctuation. The transformer’s robust mechanical design enhances resistance to short-circuit forces and thermal stress, supporting long service life and low maintenance. This solution is ideal for modern power grids requiring dependable voltage transformation and efficient energy management.
- Primary Voltage Ratings 220kV 230kV
- Secondary Voltage Ratings 34.5 kV / 13.8 kV / 18 kV
- H.V. Tap Range ± 8×1.25% HV taps or others
- Type Oil-immersed power transformer
- BIL 900kV
- Standards IEEE, ANSI, IEC, GB
- Application industrial substations, and energy infrastructure projects
- Power Rating 200 MVA
- Certificate UL, ISO, CESI
- Cooling Method ONAN/ ONAF
- Opeartion Step Down & Step Up
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
230kV 3-Phase Step-Down Power Transformer
Technical Specifications
Accessories
| Rated Power | 200 MVA |
| Rating Primary Voltage | 220kV 230kV |
| Secondary Voltage |
34.5 kV / 13.8 kV / 18 kV Customized |
| Frequency | 50/60Hz |
| Vector Group | Dyn11, YD11, YNd11 or anothers |
| Winding Material | Aluminum/Copper |
| Efficiency | As IEEE, CAS Std or Customized |
| Impedance Voltage | As IEC |
| Altitude | ≤1,000m or Customized |
| Enclosure material | Mid Steel |
| HV Bushing |
| LV Bushing |
| OLTC/NLTC |
| Lifting hook for complete transformer |
| Name plate |
| Oil temperature |
| Winding temperature |
| Radiators |
| Oil level |
| Pressure relief valve |
| CT |
Customization Optional
230kV 3-Phase Step-Down Power Transformer
The 230kV 3-Phase Step-Down Power Transformer offers a wide range of customization options to accommodate diverse grid designs and operational requirements. Electrical parameters such as primary and secondary voltage levels, rated capacity, impedance values, and insulation coordination can be tailored to specific system conditions. Winding configurations may be optimized to achieve lower losses, enhanced thermal margins, or increased short-circuit withstand capability. Tap-changing solutions, including off-circuit or on-load tap changers, can be configured with customized tap ranges and step increments to maintain voltage stability under fluctuating load conditions. Mechanical and environmental customization further enhances application flexibility.
Transformer tanks can be designed for outdoor or indoor substations, with reinforced structures available for seismic regions or demanding transport routes. Surface protection systems can be selected based on environmental exposure, including coastal climates, industrial pollution, or high-humidity regions. Cooling configurations may be adapted to ambient temperature, altitude, and load profiles to ensure stable thermal performance. Optional accessories include intelligent monitoring systems, oil temperature indicators, winding temperature sensors, pressure relief devices, remote communication interfaces, and customized noise-reduction solutions. Additional options such as alternative insulating fluids, special paint finishes, customized nameplates, and project-specific documentation packages are also available to ensure seamless integration into power infrastructure projects.
Packing and Shipping
230kV 3-Phase Step-Down Power Transformer
Packing and shipping of the 230kV step-down power transformer are executed with strict control to protect the mechanical structure and insulation integrity. Prior to packing, the transformer undergoes final inspection, surface cleaning, and protective treatment. All exposed openings are sealed, and sensitive internal components are safeguarded against moisture, dust, and corrosion. Detachable components such as bushings, radiators, conservators, and control panels are removed when necessary and packed separately in reinforced wooden or steel crates with internal cushioning and moisture-resistant barriers.
The transformer main unit is mounted on a heavy-duty transport base engineered to distribute weight evenly and reduce mechanical stress during lifting and transportation. Shock-absorbing materials and secure fastening systems are applied to protect against vibration, impact, and displacement. For extended transportation periods, oil preservation measures and desiccants are used to maintain internal insulation conditions and cleanliness.
Shipping methods are selected based on transformer dimensions, weight, route restrictions, and destination infrastructure. Transportation may be arranged using flat-rack containers, open-top containers, or break-bulk shipment for oversized units. All packing materials comply with international shipping and export regulations, including ISPM-15 standards for wooden packaging. Clear markings indicating lifting points, center of gravity, and handling instructions are applied to ensure safe loading and unloading.
Each shipment includes complete documentation such as packing lists, quality certificates, factory test reports, drawings, and operation manuals. Upon delivery, customers are provided with guidance for inspection, storage, and installation. Optional services such as on-site supervision, oil filling, commissioning support, and technical training can be offered to ensure smooth project execution and reliable commissioning.
The transformer main unit is mounted on a heavy-duty transport base engineered to distribute weight evenly and reduce mechanical stress during lifting and transportation. Shock-absorbing materials and secure fastening systems are applied to protect against vibration, impact, and displacement. For extended transportation periods, oil preservation measures and desiccants are used to maintain internal insulation conditions and cleanliness.
Shipping methods are selected based on transformer dimensions, weight, route restrictions, and destination infrastructure. Transportation may be arranged using flat-rack containers, open-top containers, or break-bulk shipment for oversized units. All packing materials comply with international shipping and export regulations, including ISPM-15 standards for wooden packaging. Clear markings indicating lifting points, center of gravity, and handling instructions are applied to ensure safe loading and unloading.
Each shipment includes complete documentation such as packing lists, quality certificates, factory test reports, drawings, and operation manuals. Upon delivery, customers are provided with guidance for inspection, storage, and installation. Optional services such as on-site supervision, oil filling, commissioning support, and technical training can be offered to ensure smooth project execution and reliable commissioning.
32
32 years of industry experience
Manufacturer Test
230kV 3-Phase Step-Down Power Transformer
Progress test
The progress test program emphasizes continuous quality monitoring throughout the manufacturing process of the 230kV step-down transformer. Raw material inspections confirm mechanical properties, dielectric strength, and insulation performance. During winding and insulation assembly, inspections verify clearances, mechanical rigidity, and uniform insulation layering. Active parts are subjected to staged drying cycles with temperature and vacuum parameters carefully controlled and recorded.
Interim electrical tests include insulation resistance measurement, DC resistance checks, and turns ratio verification to confirm design conformity. Tank manufacturing undergoes pressure resistance testing and surface protection evaluation. Before final assembly, oil tightness tests and contamination prevention inspections are conducted. Each production phase is documented to ensure consistent quality and early detection of potential deviations.
Design Tests
All transformers will be tested after finishing the production test items as follows:
♦ Leak testing with pressure for liquid-immersed transformers
♦ Test of transformer oil
♦ Measurement of voltage ratio and check of phase displacement
♦ Measurement of winding DC resistance
♦ Measurement of d. c. Insulation resistance between each winding to earth, and check of the core and frame insulation
♦ Capacitive bushing test
♦ Measurement of dissipation factor (tan δ) of the insulation system capacitances, and determination of capacitances windings-to-earth
♦ Measurement of no-load loss and current at 90%,100%,110% of rated voltage
♦ Operation test on on-load tap-changer
♦ Measurement of short-circuit impedance and load loss
♦ Lightning impulse test
♦ Induced-voltage test with partial discharge measurement
♦ Auxiliary wiring check
♦ Current transformer test
♦ Frequency response analysis test
Transformer Factory Acceptance Test
The Factory Acceptance Test (FAT) verifies that the 230kV 3-phase step-down power transformer meets all contractual and technical requirements. Routine electrical tests include winding resistance measurement, voltage ratio and vector group verification, polarity checks, and insulation resistance testing. Dielectric tests such as applied voltage and induced voltage withstand tests confirm insulation coordination and safety margins.
Performance tests evaluate no-load losses, load losses, impedance voltage, and temperature rise to verify efficiency and thermal stability. Partial discharge testing assesses insulation quality, while impulse tests confirm resistance to transient overvoltages. Mechanical inspections include oil tightness verification, tank pressure testing, cooling system operation, and accessory functionality checks. FAT results are documented for customer review and approval prior to shipment.
Routine Test - Capacitive Bushing Test
Purpose of Testing
The purpose of the capacitive bushing test is to assess the condition and insulation performance of the capacitive bushings used in transformers and other electrical equipment. This test helps identify any deterioration, leakage currents, or potential faults in the bushing's dielectric material, ensuring that the bushing can safely handle high voltages without causing electrical failures or safety hazards. It is essential for maintaining reliable transformer operation and preventing unplanned downtime.
Testing Equipment
Capacitive Bushing Tester
Insulation Resistance Tester (Megohmmeter)
High-Voltage AC/DC Power Supply
Partial Discharge Detector
Insulation Resistance Tester (Megohmmeter)
High-Voltage AC/DC Power Supply
Partial Discharge Detector
Pre-Test Preparation
Conduct a thorough visual inspection of the capacitive bushing to check for any physical damage, such as cracks, leaks, or signs of wear, which could affect the test results or pose a safety risk.
Ensure that the capacitive bushing tester or other required test equipment is properly calibrated and functioning. Inspect the test leads, clamps, and connections to ensure they are in good condition and free from damage.
Make sure all safety precautions are in place, such as grounding the equipment, ensuring the testing area is clear of unnecessary personnel, and that appropriate personal protective equipment (PPE) is being used by testing personnel.
Ensure that the capacitive bushing tester or other required test equipment is properly calibrated and functioning. Inspect the test leads, clamps, and connections to ensure they are in good condition and free from damage.
Make sure all safety precautions are in place, such as grounding the equipment, ensuring the testing area is clear of unnecessary personnel, and that appropriate personal protective equipment (PPE) is being used by testing personnel.
Test Progress
Connection of Test Equipment:
The test begins by connecting the capacitive bushing test equipment to the bushing’s terminals. The equipment typically includes a high-voltage power supply, a voltmeter, and a measurement device to assess the bushing’s capacitance and insulation. Apply Test Voltage:
A test voltage, usually an AC voltage within the specified range for the bushing, is applied to the capacitive bushing. The applied voltage is typically lower than the rated voltage of the bushing to prevent any damage during testing.
The test begins by connecting the capacitive bushing test equipment to the bushing’s terminals. The equipment typically includes a high-voltage power supply, a voltmeter, and a measurement device to assess the bushing’s capacitance and insulation. Apply Test Voltage:
A test voltage, usually an AC voltage within the specified range for the bushing, is applied to the capacitive bushing. The applied voltage is typically lower than the rated voltage of the bushing to prevent any damage during testing.
Test Standard
IEC 60076 Oil-immersed power transformers
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
Suitable for utility networks, industrial substations, and energy infrastructure projects that require efficient step-down voltage transformation from high-voltage transmission lines to distribution systems.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
Product Packaging
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What is a Transformer?A transformer is an electrical device used to change the voltage of alternating current (AC). It works on the principle of electromagnetic induction, converting high-voltage current into low-voltage current or low-voltage current into high-voltage current. Transformers are widely used in power transmission, distribution systems, and various electronic devices.
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What are the main uses of a transformer?The main use of a transformer is voltage conversion. Transformers are used in power transmission systems to help transfer electricity from power plants to consumers. In addition, transformers are also used in electronic devices such as chargers, televisions, power adapters, etc., to adjust the voltage to meet the requirements of different devices.
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Do you have UL listed?Yes, our transformer has UL listed. We have exported to America many pad mounted transformer,substation transformer and HV.
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