| Brand | Vziman |
| Model NO. | Three-Winding Oil-Immersed Power Transformer for Power Plant-220kV |
| Rated capacity | 50000kVA |
| No-load loss | 54kW |
| Series | SF11 |
This three winding oil immersed power transformer is designed for 220 kV class transmission and generation systems. It is applied where two system voltages must be linked and an auxiliary supply must be taken from the same unit: power plants, transmission substations, mining enterprises and large industrial facilities.
The transformer is available from 31.5 MVA to 180 MVA, with a high voltage winding rated 220 kV and a low voltage winding from 6.3 kV to 69 kV. A delta connected tertiary winding provides a low impedance path for third harmonic and zero sequence currents, stabilises the voltages of the star connected windings, and can supply station service or reactive compensation loads.
The unit is manufactured and tested to IEC 60076 and is suitable for both step down and step up duty in utility grids, mining sites and renewable energy integration projects.
A two winding transformer can only link two voltage levels. Where a plant or substation must serve two distribution voltages, or must feed station service loads from the main transformer, a three winding unit replaces two transformers and one high voltage bay.
For the design of this three-phase Power Transformer, advanced professional software is adopted for electromagnetic calculation, structural strength analysis, leakage magnetic field distribution, electrodynamic force calculation and electrical insulation design. These optimized design schemes lay a solid foundation for the excellent performance of the Transformer.
| Rated power (kVA) |
High Voltage (kV) |
H.V Tap range | Low Voltage (kV) |
Connection Symbol | Short-Circuit Impedance (%) |
No-load Loss (kW) | On-Load Loss (kW) | No-load Current (%) |
||||
| 9 Type | 10 Type | 11 Type | 9 Type | 10 Type | 11 Type | |||||||
| 31500 | 220 242 |
±8×1.25% ±8×1.5% |
6.3,6.6, 10.5,11, 20,34.5, 35,37, 38.5,66, 69 |
YNd11 | 10.5~14 | 38 | 34 | 30 | 135 | 128 | 128 | 0.7 |
| 40000 | 45 | 41 | 36 | 157 | 149 | 149 | 0.63 | |||||
| 50000 | 54 | 49 | 43 | 189 | 180 | 180 | 0.56 | |||||
| 63000 | 63 | 57 | 50 | 220 | 209 | 209 | 0.56 | |||||
| 90000 | 80 | 72 | 64 | 288 | 274 | 274 | 0.49 | |||||
| 120000 | 99 | 89 | 79 | 346 | 329 | 329 | 0.49 | |||||
| 150000 | 116 | 104 | 93 | 402 | 385 | 385 | 0.42 | |||||
| 180000 | 135 | 122 | 108 | 468 | 445 | 445 | 0.42 | |||||
The transformer itself costs more than one two winding unit of the same main rating, but less than two separate transformers. Civil works, foundations, high voltage switchgear, protection and space are all reduced. For most plants and substations the total installed cost is lower.
The external insulation is corrected in accordance with IEC 60071-2 and the specified insulation level is raised accordingly, so the required withstand voltage is met at site. State the altitude in the enquiry.
Yes. Routine tests are performed on every unit and witnessed factory acceptance testing can be arranged, including third party inspection. Test reports are issued with the shipment.
Certified test reports, outline and general arrangement drawings, oil processing and filling instructions, installation and commissioning manual, and a spare parts list.
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