What is an Oil Immersed Transformer?
Transformers change an alternating current (AC) to a higher or lower voltage. A current may need to move to a higher voltage as higher voltages are easier and faster to transport. A current may need to decrease its voltage in residential, commercial, and industrial areas.
One type of transformer is an oil-immersed transformer. Transformers often operate in high-energy, high-heat situations. An oil-immersed transformer suspends the transformer of a steel tank filled with oil. The oil cools and insulates the transformer. The device uses convection to move the oil around and through the transformer, cooling it off.
To avoid oil deterioration, transformer oil must be kept at an operating temperature of less than 85°C. For the transformer to run correctly and to prevent excessive oil deterioration, the daily average operating temperature should be around 30°C.
Parameters
Technical data of S11 series 35kV Loss-less and non-exciting regulation transformer
| Rated Capacity(kVA) | Voltage Combined | Vector-group | No-load Loss(w) | Load loss (w) 75℃ | No-load current(％) | Short-circuit Impedance (%) |
| HV(kV) | Tapping Ranges | LV(kV) |
| 630 | 35 | ±5％ | 3.156.310.5 | Yd11 | 830 | 7870 | 1.10 | 6.5 |
| 800 | 980 | 9410 | 1.00 |
| 1000 | 1150 | 11540 | 1.00 |
| 1250 | 1410 | 13940 | 0.90 |
| 1600 | 1700 | 16670 | 0.80 |
| 2000 | 2180 | 18380 | 0.70 |
| 2500 | 2560 | 19670 | 0.60 |
| 3150 | 35~38.5 | ±5％ | 3.156.310.5 | 3040 | 23090 | 0.56 | 7.0 |
| 4000 | 3620 | 27360 | 0.56 |
| 5000 | 4320 | 31380 | 0.48 |
| 6300 | 5250 | 35060 | 0.48 | 7.5 |
| 8000 | 35~38.5 | ±2×2.5％ | 3.153.36.36.610.511 | Ynd11 | 7200 | 38480 | 0.42 |
| 10000 | 8700 | 45320 | 0.42 |
| 12500 | 10080 | 53870 | 0.40 | 8.0 |
| 16000 | 12160 | 65840 | 0.40 |
| 20000 | 14400 | 79520 | 0.40 |
| 25000 | 17020 | 94050 | 0.32 |
| 31500 | 20220 | 112860 | 0.32 |
Applications
Well-ventilated indoors and outdoors in natural environment, if urban and rural power transmission and distribution network systems, some special oil transformers can also be used in places with harsh environments, such as seaside, chemical plants, coal mines, etc.
