161kV 50MVA Two-Winding Power Transformer – Efficient Oil-Filled Design with OLTC
The 161kV 50MVA Two-Winding Power Transformer is engineered to deliver precise voltage control and stable power transfer in high-voltage transmission and substation networks. Featuring an oil-filled insulation system combined with an On-Load Tap Changer (OLTC), this transformer allows continuous voltage adjustment under load conditions without interrupting system operation. The electromagnetic design emphasizes low losses, high operational efficiency, and consistent performance across variable load profiles. Robust mechanical construction enhances resistance to thermal expansion and short-circuit forces, ensuring long-term reliability in demanding grid environments. Optimized oil circulation supports effective heat dissipation, contributing to extended service life and reduced maintenance requirements. This transformer is well suited for modern power systems where voltage stability, operational flexibility, and dependable energy transmission are critical.
- Primary Voltage Ratings 132kV, 138kV, 161kV 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 transmission substations, utility grids, industrial power networks
- Power Rating 50MVA
- 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
161kV 50MVA Two-Winding Power Transformer – Efficient Oil-Filled Design with OLTC
Technical Specifications
Accessories
| Rated Power | 50MVA |
| Rating Primary Voltage | 132kV, 138kV, 161kV |
| 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
161kV 50MVA Two-Winding Power Transformer – Efficient Oil-Filled Design with OLTC
The 161kV 50MVA Two-Winding Power Transformer offers extensive customization to align with diverse grid configurations and operational requirements. Electrical characteristics such as rated voltage combinations, impedance levels, insulation class, and frequency can be precisely configured to match specific network conditions. The OLTC system can be customized with different tap ranges, step sizes, and control modes to ensure accurate voltage regulation under fluctuating load demands. Winding designs may be optimized for reduced losses, enhanced thermal margins, or improved short-circuit withstand capability, depending on project priorities. Mechanical and environmental customization options further enhance deployment flexibility. Tank designs can be adapted for indoor or outdoor substations, with reinforced structures available for seismic zones or heavy-duty transport conditions.
Advanced surface protection systems are selectable for coastal, industrial, or high-humidity environments to ensure long-term corrosion resistance. Cooling arrangements can be tailored to ambient temperature profiles and load cycles, supporting stable operation under continuous or peak-loading conditions. Optional accessories include digital monitoring systems, online oil condition sensors, temperature and pressure transmitters, remote OLTC control interfaces, and integration with substation automation platforms. Additional options such as low-noise construction, alternative insulating fluids, customized paint colors, and project-specific labeling are also available. All customization solutions are supported by detailed engineering analysis and verified to comply with applicable international standards.
Packing and Shipping
161kV 50MVA Two-Winding Power Transformer – Efficient Oil-Filled Design with OLTC
Packing and shipping of the 161kV 50MVA Power Transformer are carefully planned to preserve mechanical integrity and insulation performance throughout transportation. Prior to packing, the transformer undergoes final inspection, cleaning, and protective treatment. All critical openings are sealed, and sensitive components are protected against dust and moisture. Detachable items such as bushings, radiators, conservators, and control cabinets are removed when required and packed separately in reinforced crates with internal cushioning and moisture barriers.
The transformer main body is mounted on a specially designed transport base capable of supporting its full weight while minimizing stress during lifting and movement. Shock-absorbing materials and securing systems are applied to reduce vibration and mechanical impact. For extended transport durations, protective measures such as desiccants, corrosion inhibitors, and oil preservation techniques are employed to maintain internal conditions.
Shipping methods are selected based on transformer dimensions, weight, route constraints, and destination requirements. Transportation options include flat-rack containers, open-top containers, or break-bulk shipment for oversized units. All packaging materials comply with international shipping and export regulations, including ISPM-15 standards for wooden packaging. Clear handling instructions, lifting points, and center-of-gravity markings are prominently displayed to ensure safe handling during loading and unloading.
Each shipment is accompanied by comprehensive documentation, including packing lists, quality certificates, test reports, drawings, and operation manuals. Upon delivery, customers receive guidance for storage, inspection, and installation. Optional services such as on-site supervision, oil filling, OLTC commissioning, and final acceptance support can be provided to ensure smooth project execution and reliable commissioning.
The transformer main body is mounted on a specially designed transport base capable of supporting its full weight while minimizing stress during lifting and movement. Shock-absorbing materials and securing systems are applied to reduce vibration and mechanical impact. For extended transport durations, protective measures such as desiccants, corrosion inhibitors, and oil preservation techniques are employed to maintain internal conditions.
Shipping methods are selected based on transformer dimensions, weight, route constraints, and destination requirements. Transportation options include flat-rack containers, open-top containers, or break-bulk shipment for oversized units. All packaging materials comply with international shipping and export regulations, including ISPM-15 standards for wooden packaging. Clear handling instructions, lifting points, and center-of-gravity markings are prominently displayed to ensure safe handling during loading and unloading.
Each shipment is accompanied by comprehensive documentation, including packing lists, quality certificates, test reports, drawings, and operation manuals. Upon delivery, customers receive guidance for storage, inspection, and installation. Optional services such as on-site supervision, oil filling, OLTC commissioning, and final acceptance support can be provided to ensure smooth project execution and reliable commissioning.
32
32 years of industry experience
Manufacturer Test
161kV 50MVA Two-Winding Power Transformer – Efficient Oil-Filled Design with OLTC
Progress test
The Progress Test program for the 161kV 50MVA two-winding oil-immersed power transformer is implemented to monitor quality and performance at each critical manufacturing milestone. The process begins with verification of core steel, copper conductors, insulating paper, pressboard, and insulating oil to ensure full compliance with approved technical specifications. During core assembly, inspections focus on lamination alignment, clamping pressure, and magnetic path integrity. Coil winding operations are continuously monitored for conductor tension, insulation layering accuracy, and dimensional consistency.
Following winding completion, the active part undergoes controlled drying and vacuum treatment to eliminate residual moisture. Intermediate electrical checks, including DC resistance, turns ratio, and insulation resistance measurements, are conducted before tanking. Tank fabrication and welding quality are examined through visual inspection and non-destructive testing where required. Prior to final assembly, oil tightness and cleanliness inspections are performed. All progress test results are logged, reviewed, and approved to ensure readiness for 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 verifies the operational readiness of the 161kV 50MVA two-winding oil-immersed power transformer under simulated service conditions. Routine electrical tests include winding resistance measurement, ratio and phase displacement verification, polarity checks, and insulation resistance measurement. High-voltage dielectric testing, comprising applied voltage and induced voltage tests, confirms insulation coordination and safety margins.
Thermal and efficiency performance is validated through temperature rise testing, loss measurement, and impedance evaluation. Partial discharge testing assesses internal insulation condition, while impulse tests confirm resilience against lightning and switching surges. Mechanical and functional inspections cover tank pressure testing, oil circulation performance, cooling equipment operation, and OLTC switching accuracy. Oil quality analysis ensures dielectric strength and cleanliness meet specification limits. All FAT outcomes are compiled into formal test records and approved before release for delivery.
Routine Test - On load Loss Test
Purpose of Testing
The purpose of On-load Loss Test is to measure the active power loss of the transformer under rated voltage and rated load, evaluate its energy efficiency level and design compliance, and provide a basis for energy consumption calculation and performance optimization during operation.
Testing Equipment
Power transformer test system (e.g. OMICRON, ISA, Tettex, Vanguard, etc.)
Voltage source and current source (usually rated voltage, or adjusted according to the test standard, such as 10 KV, 20 KV, 35 KV, etc.)
Temperature and humidity meter (used to record ambient temperature and humidity for correction of test data)
Voltage source and current source (usually rated voltage, or adjusted according to the test standard, such as 10 KV, 20 KV, 35 KV, etc.)
Temperature and humidity meter (used to record ambient temperature and humidity for correction of test data)
Pre-Test Preparation
Disconnect the transformer high voltage, low voltage and neutral power supply to ensure that the equipment is properly grounded and safely discharged.
The test environment should be dry and rainless, with a relative humidity of less than 75% and a recommended temperature range of 20–30°C.
The test environment should be dry and rainless, with a relative humidity of less than 75% and a recommended temperature range of 20–30°C.
Test Progress
Connect the Test Instrument:
Connect the test equipment to the appropriate terminals of the device under test and ensure that all wiring is correct and the device is well grounded.
Apply Test Voltage:
Apply the specified test voltage at the rated frequency and adjust the low voltage side to maintain the rated current (or specified current).
Connect the test equipment to the appropriate terminals of the device under test and ensure that all wiring is correct and the device is well grounded.
Apply Test Voltage:
Apply the specified test voltage at the rated frequency and adjust the low voltage side to maintain the rated current (or specified current).
Test Standard
IEC 60076 Oil-immersed power transformers
Measure and Record
Start the test and record the following parameters:
On-Load Loss Power
Input Power and Output Power
Current
Voltage
Temperature (temperature rise or winding temperature)
Ambient temperature and humidity during the test
On-Load Loss Power
Input Power and Output Power
Current
Voltage
Temperature (temperature rise or winding temperature)
Ambient temperature and humidity during the test
Temperature Correction
The measured loss data is corrected based on a reference temperature (usually 20°C) to ensure the accuracy of the results.
Repeat Testing (if necessary)
Test different tap positions (Tap Changer) and record and compare the load loss data of each tap point.
Evaluation Criteria (Reference)
Evaluate the test results based on the equipment type and manufacturer requirements. If the load losses are low and the efficiency is high, it is considered "normal".
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
This transformer is suitable for transmission substations, utility grids, industrial power networks, and infrastructure projects requiring precise voltage regulation, continuous operation, and reliable high-voltage power transfer.
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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