133kV 135kV Three-Phase Power Transformer – High Voltage Substation Equipment
The 133kV / 135kV Three-Phase Power Transformer is developed for high-voltage substations requiring dependable power conversion, grid stability, and long-term operational security. Designed as core infrastructure equipment, it supports continuous duty under fluctuating electrical loads and complex grid conditions. The transformer integrates a high-strength magnetic core, precision-manufactured windings, and a stable oil-immersed insulation system to achieve controlled losses and consistent voltage performance. Its structural design prioritizes mechanical durability, enabling safe operation under electrical stress, thermal expansion, and external environmental factors. Engineered for outdoor substation installation, the transformer ensures reliable service life with reduced maintenance demand. Compliance with international power equipment standards makes it suitable for modern transmission and substation systems where operational reliability, safety, and efficiency are essential.
- Primary Voltage Ratings 133kV, 135kV, 138kV or others
- Secondary Voltage Ratings 32.4/13.8/11/10.5/6.6/6.3kV or customized
- H.V. Tap Range ± 8×2.5% HV taps or others
- Type Oil-immersed power transformer
- BIL up to 350kV
- Standards IEEE, ANSI, IEC
- Application high-voltage transmission substations, regional grid interconnections, utility power networks
- Power Rating 135kVA - 25MVA
- Certificate UL, CESI, ISO, KEMA
- Cooling Method ONAN/ ONAF
- Opeartion Step Down & Step Up
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
133kV 135kV Three-Phase Power Transformer – High Voltage Substation Equipment
Technical Specifications
Accessories
| Rated Power | 135kVA - 25MVA |
| Rating Primary Voltage | 133kV, 135kV |
| Secondary Voltage |
32.4/13.8/11/10.5/6.6/6.3 kV Customized |
| Frequency | 50/60Hz |
| Vector Group | Dyn11, YD11, YNd11 |
| 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
133kV 135kV Three-Phase Power Transformer – High Voltage Substation Equipment
The 133kV / 135kV Three-Phase Power Transformer offers comprehensive customization to align with varying grid structures, operational philosophies, and regulatory frameworks. Electrical customization options include tailored rated capacity, adjustable voltage ratios, selectable frequency configurations, and customized impedance levels to ensure seamless integration with existing transmission networks. Multiple-phase connection and vector group arrangements can be engineered to match system requirements. Winding design options allow optimization for efficiency, thermal performance, or mechanical robustness, depending on project priorities. Voltage regulation can be configured through customized tap changer solutions, providing accurate control during load variation or network expansion. Mechanical and functional customization further enhances adaptability for diverse installation environments.
The transformer tank can be designed with reinforced structures for regions exposed to seismic activity, high wind loads, or transportation constraints. Surface protection systems may be upgraded for corrosive atmospheres such as coastal or industrial zones. Cooling configurations can be adapted to meet ambient temperature profiles and operational duty cycles, supporting stable thermal performance. Optional equipment includes comprehensive protection and monitoring systems such as gas detection relays, multi-point temperature sensing, oil level supervision, pressure relief devices, and digital monitoring interfaces. Noise control solutions, alternative insulating fluids, customized color schemes, and project-specific labeling are also available. Each customized transformer undergoes dedicated engineering validation to ensure full compliance with technical standards and long-term operational reliability.
Packing and Shipping
133kV 135kV Three-Phase Power Transformer – High Voltage Substation Equipment
Packing and shipping of the 133kV / 135kV Three-Phase Power Transformer are executed using a structured protection strategy to maintain equipment integrity throughout transportation. Prior to packing, the transformer is subjected to final inspection, surface cleaning, and preservation treatment. All external openings are sealed, and exposed components are protected against moisture, dust, and mechanical impact. Accessories such as bushings, cooling elements, conservators, and monitoring devices are detached when required and packed separately in reinforced crates with internal shock absorption and moisture-resistant linings.
The transformer's main body is secured onto a heavy-duty transport frame engineered to support weight distribution and reduce vibration during handling. Stabilization systems, including reinforced bracing and cushioning materials, are applied at critical structural points. Protective wrapping layers and desiccant systems are used to maintain internal dryness and protect insulation components. For extended transport durations or overseas shipment, additional measures such as inert gas filling or vacuum preservation may be applied to safeguard internal conditions.
Transportation methods are selected based on transformer dimensions, route conditions, and delivery destination. Options include flat-rack container shipment, open-top container loading, or break-bulk transport for oversized units. All packing materials comply with international shipping and export standards, including ISPM-15 requirements for wooden components. Clear markings indicate lifting positions, center of gravity, orientation requirements, and safety precautions to ensure correct handling throughout transit.
Each shipment is accompanied by complete documentation, including packing lists, inspection records, quality certificates, test reports, drawings, and operation manuals. Upon arrival, customers receive detailed guidance for unloading, storage, and installation. Optional on-site services such as supervision, oil treatment, reassembly, and commissioning support are available to ensure efficient project execution and reliable transformer commissioning.
The transformer's main body is secured onto a heavy-duty transport frame engineered to support weight distribution and reduce vibration during handling. Stabilization systems, including reinforced bracing and cushioning materials, are applied at critical structural points. Protective wrapping layers and desiccant systems are used to maintain internal dryness and protect insulation components. For extended transport durations or overseas shipment, additional measures such as inert gas filling or vacuum preservation may be applied to safeguard internal conditions.
Transportation methods are selected based on transformer dimensions, route conditions, and delivery destination. Options include flat-rack container shipment, open-top container loading, or break-bulk transport for oversized units. All packing materials comply with international shipping and export standards, including ISPM-15 requirements for wooden components. Clear markings indicate lifting positions, center of gravity, orientation requirements, and safety precautions to ensure correct handling throughout transit.
Each shipment is accompanied by complete documentation, including packing lists, inspection records, quality certificates, test reports, drawings, and operation manuals. Upon arrival, customers receive detailed guidance for unloading, storage, and installation. Optional on-site services such as supervision, oil treatment, reassembly, and commissioning support are available to ensure efficient project execution and reliable transformer commissioning.
32
32 years of industry experience
Manufacturer Test
133kV 135kV Three-Phase Power Transformer – High Voltage Substation Equipment
Progress test
Progress testing for the 133kV / 135kV Three-Phase Power Transformer is conducted at defined manufacturing stages to maintain strict process control. Incoming materials—including magnetic steel, conductors, insulation components, and insulating oil—are verified for compliance with approved specifications. During core assembly and winding production, inspections focus on dimensional accuracy, mechanical alignment, and insulation placement. The active assembly undergoes controlled drying and vacuum treatment, with continuous monitoring to ensure optimal moisture reduction and insulation readiness.
Intermediate electrical evaluations include continuity checks, winding resistance measurements, and preliminary ratio verification. Tank fabrication is examined for welding integrity, dimensional consistency, and surface protection quality. Pressure and sealing tests are conducted before oil filling to confirm structural tightness. All progress test data are recorded and reviewed to ensure traceability, early detection of deviations, and consistent manufacturing quality prior to final acceptance testing.
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) for the 133kV / 135kV Three-Phase Power Transformer is performed after complete assembly to validate compliance with contractual specifications and applicable standards. Electrical routine tests include winding resistance measurement, voltage ratio accuracy verification, vector group confirmation, polarity checks, and insulation resistance testing. Dielectric tests, such as applied voltage and induced overvoltage withstand tests, confirm insulation reliability.
Performance assessments evaluate no-load losses, load losses, impedance characteristics, and temperature rise to verify efficiency and thermal stability. Partial discharge testing assesses insulation condition, while impulse testing validates resistance to transient overvoltage events. Mechanical inspections include tank pressure testing, oil leakage checks, cooling system operation verification, and tap changer functionality testing. Oil samples are analyzed for dielectric strength and cleanliness. All FAT results are compiled into a formal report and approved prior to shipment release.
Routine Test - Winding Resistance
Purpose of Testing
The purpose of winding resistance testing is to detect the continuity and connection quality of the internal conductors of the motor or transformer windings, and to promptly detect potential faults such as open circuits, poor contact or local heating.
Testing Equipment
Winding resistance tester (e.g. OMICRON, DV Power, Raytech, Megger, ISA, etc.)
Test voltage source (commonly used are 6V, 10V, 20V, 40V or 100V, depending on the equipment model or customer requirements)
Temperature and humidity meter (used to record the ambient temperature and humidity during the test)
Test voltage source (commonly used are 6V, 10V, 20V, 40V or 100V, depending on the equipment model or customer requirements)
Temperature and humidity meter (used to record the ambient temperature and humidity during the test)
Pre-Test Preparation
Check if the instrument has been calibrated to ensure the test accuracy.
Disconnect the electrical connection between the test cable and the equipment to ensure that there is no external current or voltage interference.
Select a suitable voltage range for testing and set the test voltage according to the equipment requirements.
Disconnect the electrical connection between the test cable and the equipment to ensure that there is no external current or voltage interference.
Select a suitable voltage range for testing and set the test voltage according to the equipment requirements.
Test Progress
Connect the Test Instrument:
Connect the test equipment to the winding terminals of the device under test, making sure the connections are secure and properly grounded to avoid measurement errors.
Apply Test Voltage:
Select the appropriate test current according to the equipment specifications (such as test current for low-voltage windings, single-phase or three-phase windings).
Connect the test equipment to the winding terminals of the device under test, making sure the connections are secure and properly grounded to avoid measurement errors.
Apply Test Voltage:
Select the appropriate test current according to the equipment specifications (such as test current for low-voltage windings, single-phase or three-phase windings).
Test Standard
IEC 60076 Oil-immersed power transformers
Measure and Record
Start the test and record the following parameters:
Winding resistance (usually expressed in units of "Ω")
Test current (A)
Test voltage (V)
Temperature (record the winding temperature before and after the test)
Winding resistance (usually expressed in units of "Ω")
Test current (A)
Test voltage (V)
Temperature (record the winding temperature before and after the test)
Temperature Correction
The measured winding resistance values are converted to a reference temperature (usually 20°C) based on a temperature correction formula to allow accurate evaluation and comparison.
Repeat Testing (if necessary)
Test the different windings (high voltage, medium voltage, low voltage) separately and make sure to record the resistance value of each winding.
Evaluation Criteria (Reference)
Resistance deviation is less than 5% (normal)
Resistance deviation is between 5% and 10% (warning)
Resistance deviation exceeds 10% (further inspection or corrective action is required)
Resistance deviation is between 5% and 10% (warning)
Resistance deviation exceeds 10% (further inspection or corrective action is required)
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
This transformer is suitable for high-voltage transmission substations, regional grid interconnections, utility power networks, industrial power distribution hubs, and large infrastructure projects requiring reliable, safe, and long-term high-voltage power transformation.
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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