H61 H59 20kV(15kV) Hermetical Oil Immersed Distribution Transformer
Product Description
20kV (15kV) Hermetical Oil Immersed Distribution Transformer SM Series
We generally manufacture distribution transformers in this power range, mainly in two different types:
1. Transformer with conservator tank (S),
2. Hermetically sealed type (SM),
Below table will help to engineers to select the best option according to environmental conditions which transformer works in:
| High Environmental Temperature | High Altitude | Rural Network | High Humidity | Over Load Conditions | Unstable Loading | |
|---|---|---|---|---|---|---|
| S | ⇑ | ⇑ | ⇓ | ⇓ | ⇑ | ⇑ |
| SM | ⇓ | ⇓ | ⇑ | ⇑ | ⇓ | ⇓ |
Meanwhile here is the advantage-disadvantage of the S/SM types:
In SM type, tank pressure is more than S type. S type generally works under low pressure due to its open to atmosphere,
In SM type, cooling/insulation oil does not contact to the air (theoretically). Therefore oil maintenance period is longer than S type,
SM type transformers and their related parts generally work under higher temperature (If we evaluate S/SM work under same conditions).
♦ Hermetically Sealed Type:
Oil type distribution transformers can change the input and output voltages up to 36 kV voltage levels with a capacity of 5000kVa power in desired ratios. The heat generated during operation is maintained and cooled at the normal temperature level with transformer oil. This type of transformer can be examined under two main headings as hermetic and conservator tank:
They are produced in a range of 25 – 5000 kVA, up to 36 kV high voltage level, with three or single phase, oiled, naturally cooled (ONAN), idle tap changer, or automatic on-load tap changer, both externally and indoors. Hermetic oil type distribution transformers are manufactured by filling the oil under a vacuum by balancing the oil pressure and atmospheric pressure at the desired temperature and not allowing the cooling oil to come into contact with the atmosphere.
As a result of changing oil pressure due to thermal changes in hermetic oil type distribution transformers, the internal heat is controlled by a natural conservator and contraction of boiler wave walls. Mechanical design and manufacturing are made to withstand these effects.
Hermetic oil type distribution transformers are shorter in length than a conservator tank transformer”. Therefore, it can be used in smaller areas.
Since the oil does not come into contact with the atmosphere in hermetic transformers, it does not require oil change in certain periods as in a transformer with a conservator tank.
Parameters
20kV (15kV) Three phase hermetical oil immersed distribution transformer, SM series
| Main Technical Parameters | ||||||||
| Rated capacity(kVA) | Primary voltage (kV) | H.V. tap range (%) | Secondary voltage(V) | Connection group | No-load loss (W) | Load loss (W) | No-load current (%) | Short circuit impedance (%) |
| 50 | 20kV 22kV 24kV | ±5% ±2x2.5% | 400 415 433 | Dyn11 Yyn0 | 210 | 1270 | 2.0 | 4.5 |
| 100 | 290 | 2120 | 1.8 | 4.5 | ||||
| 160 | 360 | 2970 | 1.6 | 4.5 | ||||
| 200 | 430 | 3500 | 1.5 | 4.5 | ||||
| 250 | 510 | 4160 | 1.4 | 4.5 | ||||
| 315 | 610 | 5010 | 1.4 | 4.5 | ||||
| 400 | 730 | 6050 | 1.3 | 4.5 | ||||
| 500 | 860 | 7280 | 1.2 | 4.5 | ||||
| 630 | 1040 | 8280 | 1.1 | 4.5 | ||||
| 800 | 1230 | 9900 | 1.0 | 4.5 | ||||
| 1000 | 1440 | 12150 | 1.0 | 4.5 | ||||
| 1250 | 1760 | 14670 | 0.9 | 4.5 | ||||
| 1600 | 2120 | 17550 | 0.8 | 4.5 | ||||