100kV 200kVA 250kVA 315kVA Three-Phase Oil-Immersed Substation Power Transformer
This 100kV three-phase oil-immersed substation power transformer is engineered for stable voltage transformation across 200kVA, 250kVA, and 315kVA capacity ranges. Designed for medium to high-voltage distribution networks, it delivers exceptional reliability, thermal endurance, and operational efficiency in substations, industrial plants, and utility distribution grids. The transformer utilizes high-grade insulation, precision-wound copper conductors, and robust core materials to ensure low losses, long service life, and consistent performance under demanding electrical and environmental conditions. Its sealed oil-immersed structure enhances insulation strength and optimizes heat dissipation for safe and continuous operation.
- Primary Voltage Ratings 100kV, 110kV, 115kV or others
- Secondary Voltage Ratings 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 distribution substations, industrial power systems, utility grids, and regional electrical networks
- Power Rating 200kVA 250kVA 315kVA
- Certificate UL , CESI , CE
- Cooling Method ONAN/ ONAF
- Opeartion Step Down & Step Up
Technical Specifications
Customization Optional
Packing and Shipping
Manufacturer Test
Routine Testing
Application
Technical Specifications
100kV 200kVA 250kVA 315kVA Three-Phase Oil-Immersed Substation Power Transformer
Technical Specifications
Accessories
| Rated Power | 200kVA 250kVA 315kVA |
| Rating Primary Voltage | 100kv, 110kV, 115kV |
| Secondary Voltage |
6.3 kV 6.6 kV 10.5 kV 11 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
100kV 200kVA 250kVA 315kVA Three-Phase Oil-Immersed Substation Power Transformer
Customers may select a wide range of customization options to ensure the transformer meets precise project and operational requirements. Optional configurations include variable-rated capacities within 200kVA, 250kVA, and 315kVA, alternative core materials, optimized no-load and on-load tap-changer configurations, and enhanced insulation classes suitable for extreme climates. Winding materials can be specified as high-conductivity copper or aluminum based on budget, efficiency needs, or system compatibility. Additional thermal management features, harmonic solutions, and tailored impedance designs are also available to support specific grid behaviors and load characteristics. Protection systems, such as Buchholz relays, pressure relief valves, temperature monitoring devices, and advanced digital sensors for remote SCADA integration, can be integrated as required.
Further customization options cover enclosure types, corrosion-resistant coatings, seismic-rated structures, and fire-safety enhancements to ensure prolonged durability in challenging industrial or outdoor environments. Oil selections include standard mineral oil, environmentally friendly biodegradable oils, or high-temperature-resistant options, depending on application needs. Clients may also request specialized testing standards, country-specific certification compliance, customized terminal arrangements, or unique installation interfaces to streamline project commissioning. Tailored nameplate data, branding options, and detailed documentation packages can be provided to meet international utility, EPC, and government procurement specifications.
Packing and Shipping
100kV 200kVA 250kVA 315kVA Three-Phase Oil-Immersed Substation Power Transformer
Each transformer is packaged in compliance with international heavy-equipment export standards to ensure safety during long-distance transportation. The unit is secured within a reinforced wooden or steel-framed crate, with shock-absorption padding integrated around oil tanks, bushings, and radiators. Protective sealing films are applied to prevent moisture intrusion, dust accumulation, and corrosion during delivery. All external protrusions—including HV and LV terminals—are additionally shielded to prevent mechanical damage. Accessories such as tap-changer handles, gauges, and spare components are packed separately in labeled, anti-impact containers.
Loading operations are conducted with certified lifting equipment to maintain structural integrity. The base of the transformer is equipped with robust lifting lugs and forklift channels to facilitate safe handling. When required, vacuum sealing or nitrogen-filled preservation methods are deployed to maintain internal oil and insulation stability throughout extended transit periods. Every shipment is accompanied by vibration monitoring tags and tilt indicators to ensure the equipment is transported upright and in accordance with manufacturer guidelines.
For international transport, the transformers can be shipped via sea freight, air cargo (for smaller units), or multimodal logistics chains. All shipping documentation—including packing lists, inspection reports, bills of lading, and certificates of origin—is prepared to comply with export requirements in the destination market. Transformers destined for extreme climates may receive additional thermal-stable packaging and anti-rust treatment to ensure readiness upon arrival.
Upon delivery, customers receive a detailed unpacking guide, installation instructions, and recommended storage procedures. Field service support can be arranged for offloading supervision, site inspection, and commissioning. Each transformer undergoes a final verification process prior to shipping, ensuring that all components, protective devices, and accessories are complete and ready for immediate deployment.
Loading operations are conducted with certified lifting equipment to maintain structural integrity. The base of the transformer is equipped with robust lifting lugs and forklift channels to facilitate safe handling. When required, vacuum sealing or nitrogen-filled preservation methods are deployed to maintain internal oil and insulation stability throughout extended transit periods. Every shipment is accompanied by vibration monitoring tags and tilt indicators to ensure the equipment is transported upright and in accordance with manufacturer guidelines.
For international transport, the transformers can be shipped via sea freight, air cargo (for smaller units), or multimodal logistics chains. All shipping documentation—including packing lists, inspection reports, bills of lading, and certificates of origin—is prepared to comply with export requirements in the destination market. Transformers destined for extreme climates may receive additional thermal-stable packaging and anti-rust treatment to ensure readiness upon arrival.
Upon delivery, customers receive a detailed unpacking guide, installation instructions, and recommended storage procedures. Field service support can be arranged for offloading supervision, site inspection, and commissioning. Each transformer undergoes a final verification process prior to shipping, ensuring that all components, protective devices, and accessories are complete and ready for immediate deployment.
32
32 years of industry experience
Manufacturer Test
100kV 200kVA 250kVA 315kVA Three-Phase Oil-Immersed Substation Power Transformer
Progress test
The progress test includes a series of intermediate inspections conducted during transformer production to verify manufacturing quality and compliance with design specifications. Core lamination assembly is inspected for alignment and loss performance, while coil winding procedures are monitored to ensure correct tension, insulation layering, and conductor accuracy. Oil tank fabrication and welding undergo dimensional checks and non-destructive testing to guarantee structural integrity. Electrical clearances, insulation materials, and tap-changer mechanisms are verified during assembly. Partial discharge tests, ratio checks, and resistance measurements may be performed during key production stages to confirm stability and alignment with technical requirements.
Design Tests
All transformers will be tested after finishing the production test items as below:
♦ 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
Factory Acceptance Testing (FAT) includes a full suite of electrical and mechanical evaluations conducted before shipment. Standard tests include turns-ratio measurement, winding resistance, insulation resistance, vector group verification, and applied and induced voltage tests. No-load loss, load loss, and impedance measurements are performed to ensure the transformer meets efficiency and performance specifications. Dielectric tests, oil quality evaluations, and partial discharge assessments validate insulation strength and stability. Mechanical checks include visual inspection, tank pressure testing, and verification of protection devices and accessories. FAT ensures the transformer complies fully with IEC, IEEE, or customer-specified standards.
Routine Test - No Load Loss Test
Purpose of Testing
The purpose of No Load Loss Test is to measure the power loss of the equipment when it is not loaded to evaluate the iron loss and other core losses. This test can help understand the energy efficiency of the equipment and help determine the performance of the transformer or motor when it is running at no load.
Testing Equipment
No Load Loss tester (e.g. OMICRON, Megger, Schneider Electric, etc.)
Voltage source (usually 230V, 400V or customized according to customer requirements to adapt to different equipment)
Power analyzer (used to measure power loss and efficiency)
Ammeter and voltmeter
Temperature and humidity meter
Voltage source (usually 230V, 400V or customized according to customer requirements to adapt to different equipment)
Power analyzer (used to measure power loss and efficiency)
Ammeter and voltmeter
Temperature and humidity meter
Pre-Test Preparation
Disconnect the power supply of the device and ensure that the device is properly grounded and discharged to ensure safe operation.
Please ensure that the test is carried out in a suitable environment with a relative humidity of less than 75% and avoid rainy days or extreme weather (recommended temperature range: 20-30°C).
Please ensure that the test is carried out in a suitable environment with a relative humidity of less than 75% and avoid rainy days or extreme weather (recommended temperature range: 20-30°C).
Test Progress
Connect the Test Instrument:
Connect the test equipment to the high voltage side of the transformer, making sure the wiring is correct and the equipment is grounded.
Apply Test Voltage:
Usually it is 110% of the rated voltage, for example, if the rated voltage of the transformer is 33 KV, apply 36.3 KV (110%).
Connect the test equipment to the high voltage side of the transformer, making sure the wiring is correct and the equipment is grounded.
Apply Test Voltage:
Usually it is 110% of the rated voltage, for example, if the rated voltage of the transformer is 33 KV, apply 36.3 KV (110%).
Measure and Record
Start the test and record the following parameters:
No Load Current
No Load Loss
Power Factor
Current
Voltage
Temperature and Humidity
No Load Current
No Load Loss
Power Factor
Current
Voltage
Temperature and Humidity
Temperature Correction
The power loss of the test results is corrected to a reference temperature (usually 20°C) to ensure an accurate evaluation.
Repeat Testing (if necessary)
Test at different rated voltages, especially when the transformer has multiple capacity levels, and perform no-load loss tests for each capacity level separately.
Evaluation Criteria (Reference)
No-load loss ≤ 0.2% rated power (excellent)
No-load loss < 0.2% ≤ 0.5% rated power (good)
No-load loss > 0.5% rated power (further inspection or corrective action required)
No-load loss < 0.2% ≤ 0.5% rated power (good)
No-load loss > 0.5% rated power (further inspection or corrective action required)
*These comprehensive tests ensure that each transformer meets performance standards and operates
reliably under various conditions.
Application
100kV 200kVA 250kVA 315kVA Three-Phase Oil-Immersed Substation Power Transformer supports stable voltage transformation for commercial facilities, infrastructure projects, and medium-scale power distribution zones, ensuring reliable performance in both urban and rural grid environments.
Technical Advantages
● 30+ years of manufacturing experience
● ISO and UL certified production
● Customized cable and transformer solutions
Product Packaging
Transformers Packaging (1)
Transformers Packaging (2)
Transformers Packaging (3)
Transformers Packaging (4)
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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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