TRANSFORMER PARTS AND FUNCTIONS
Transformers/ distribution transformers/ power transformers facilitate the delivery of electrical energy with minimal power loss. The basic parts of a transformer are the core, primary and secondary windings. In addition to these components, there are many other components such as insulation, transformer oil, cooling arrangements, protective relays, enclosures, etc., available in larger transformers.
Table of contents:
1. Core - Parts of transformer
3. Insulating materials- transformer part
In the image below, we will show you the transformer parts completely.
Transformer parts diagram
1. | Oil filter valve | 17. | Oil drain valve |
2. | Conservator | 18. | Jacking boss |
3. | Buchholz relay | 19. | Stopper |
4. | Oil filter valve | 20. | Foundation bolt |
5. | Pressure-relief vent | 21. | Grounding terminal |
6. | High-voltage bushing | 22. | Skid base |
7. | Low-voltage bushing | 23. | Coil |
8. | Suspension lug | 24. | Coil pressure plate |
9. | B C T Terminal | 25. | Core |
10. | Tank | 26. | Terminal box for protective devices |
11. | De-energized tap changer | 27. | Rating plate |
12. | Tap changer handle | 28. | Dial thermometer |
13. | Fastener for core and coil | 29. | Radiator |
14. | Lifting hook for core and coil | 30. | Manhole |
15. | End frame | 31. | Lifting hook |
16. | Coil pressure bolt | 32. | Dial type oil level gauge. |
The main part of a transformer is include 10 parts:
1. Core - Parts of transformer
The core of the transformer is used to support the windings. It is made of soft iron to reduce eddy current loss and hysteresis loss, and provide a low reluctance path for flux current. The diameter of the transformer core is directly proportional to the copper loss and inversely proportional to the iron loss.
2. Winding
The winding consists of many turns of copper coils bundled together, each bundle being joined together to form a complete winding. The coils can be based on an input-output supply or on a voltage range. Power supply-based windings are classified as primary and secondary, that is, the coil to which the input and output voltages are applied, respectively. On the other hand, coils based on voltage range can be classified into high voltage coils and low voltage coils
3. Insulating materials- transformer part
Insulating materials such as paper and cardboard are used to isolate the primary and secondary coils from each other as well as the transformer core. These coils are made of copper due to their high conductivity and ductility. The high conductivity minimizes the amount of copper required and minimizes loss. Furthermore, the high ductility results in easy bending of the conductor into tight coils around the core, while minimizing copper and winding weight.
4. Transformer oil
Transformer oil insulates as well as cools the core assembly and windings. The core and windings of the transformer shall be completely immersed in an oil usually containing hydrocarbon mineral oil.
5. Conservator
The conservator is an airtight metal cylindrical drum mounted above the transformer to store transformer oil. It is vented at the top and is only half filled with oil to allow expansion and contraction during temperature changes. However, the transformer's main tank is connected to the storage unit, which is completely filled with oil through a pipe.
Oil conservator of a transformer
6. Breather
The breather is a cylindrical container filled with silica gel, which is used to keep the air entering the vessel from becoming damp. This is because insulating oil reacts with moisture which can affect the insulation and cause internal failures, so it is important to keep the air free of moisture. As the air passes through the silica gel in a breathing tube, the moisture components are absorbed by the silica crystals.
Transformer breather
7. Tap changer-transformer parts
A tap changer is used to balance voltage variations in the transformer. There are two types of tap changers - on load and off load. In a loaded tap changer, tapping can be changed without isolating the transformer from the supply, while at no load the transformer needs to be disconnected from the supply.
On load tap changer
8. Cooling tube
As the name suggests, the cooling tube is used to cool the transformer oil. The circulation of oil in the transformer can be natural or forced. In the case of natural circulation, when the oil temperature rises, the hot oil naturally moves upward and the cold oil moves downward, while in the case of forced circulation, a permanent pump is used.
9. Buchholz Relay
Placed on the connecting pipe that runs from the main storage tank to the storage tank, the Buchholz Relay senses faults in the transformer. It operates on the gases emitted by the breakdown of transformer oil during internal faults. So this device is used to sense and in turn protect the transformer from internal faults.
10. Explosion vent
The boiling hot oil from the transformer is drained out in case of internal fault through the vent of the generator to avoid explosion of the transformer. This is generally placed above the level of the conservatory tank.
For any query please click OR mail at cosmostat@gmail.com