transformer and transformer's part

What is transformer -

Transformer is a statics device which is used for transfer the electrical power from one circuit to another circuit without change in frequency and it’s work on the fraday’s law of mutal induction.

  

part's transformer-

1. Laminated core,
2. Windings,
3. Insulating materials,
4. Transformer oil,
5. Tap changer,
6. Oil Conservator,
7. Breather,
8. Cooling tubes,
9. Buchholz Relay,
10. Explosion vent,
11. drain off.

 Breather –most of the power generation companies use silica gel breather  fitted to the conservator of oil filled transformers. The purpose of these silica gel breather is to absorb the moisture in the air sucked  in the transformer during the breathing process.

 Dain off- it is used for the flow of transformer oil from the transformer tank .

Radiator – when load Is increases then transformer are getting heated then the radiator is used for Cooling the oil,tank also .

Buchholz relay- it is used for safety purpose (rated more than 500 KVA) it is used for protection of transformer from the fault occurring inside the transformer, such as impulse breakdown of insulating oil, insulation failure of turns.

Explosion vent – in transformer is to prevent damage of the transformer tank be releasing any excessive pressure generate inside the transformer. 

 cooling tube-Cooling tubes are used to cool the transformer oil. The transformer oil is circulated through the cooling tubes. The circulation of the oil may either be natural or forced. In natural circulation, when the temperature of the oil rises the hot oil naturally rises to the top and the cold oil sinks downward. Thus the oil naturally circulates through the tubes. In forced circulation, an external pump is used to circulate the oil.
Tap changer-The output voltage of transformers vary according to its input voltage and the load. During loaded conditions, the voltage on the output terminal decreases, whereas during off-load conditions the output voltage increases. In order to balance the voltage variations, tap changers are used. Tap changers can be either on-load tap changers or off-load tap changers. In an on-load tap changer, the tapping can be changed without isolating the transformer from the supply. In an off-load tap changer, it is done after disconnecting the transformer. Automatic tap changers are also available.
Conservator -The conservator conserves the transformer oil. It is an airtight, metallic, cylindrical drum that is fitted above the transformer. The conservator tank is vented to the atmosphere at the top, and the normal oil level is approximately in the middle of the conservator to allow the oil to expand and contract as the temperature varies. The conservator is connected to the main tank inside the transformer, which is completely filled with transformer oil through a pipeline.

Insulating Materials

Insulating paper and cardboard are used in transformers to isolate primary and secondary winding from each other and from the transformer core.

Transformer oil is another insulating material. Transformer oil performs two important functions: in addition to insulating function, it can also cool the core and coil assembly. The transformer's core and winding must be completely immersed in the oil. Normally, hydrocarbon mineral oils are used as transformer oil. Oil contamination is a serious problem because contamination robs the oil of its dielectric properties and renders it useless as an insulating medium.

Core

The core acts as support to the winding in the transformer. It also provides a low reluctance path to the flow of magnetic flux. It is made of laminated soft iron core in order to reduce eddy current loss and Hysteresis loss. The composition of a transformer core depends on such as factors voltage, current, and frequency. The diameter of the transformer core is directly proportional to copper loss and is inversely proportional to iron loss. If the diameter of the core is decreased, the weight of the steel in the core is reduced, which leads to less core loss of the transformer and the copper loss increase. When the diameter of the core is increased, the vise versa occurs.