COOLING OF TRANSFORMER
With a transformer is connected to the mains, het is produced in the transformer due to various losses in it. This increase its temperature. In fact, output of the transformer is limited by the raise in temperature. Therefore, some means are provided to cool down the transformer so that the raise in temperature may not go beyond the permissible limits.
Most of the electrical machine have rotatingpart, therefore, it is easy to cool down such machine by providing fan on the shaft and ducts in their construction. But in case of transformer there is no rotating part, therefore, it is difficult to cool down the inner part of the transformer. However, depending upon the size of transformer, various method have been evolved to dissipate heat produced in the transformer. These are :
1. Natural cooling
- Air natural cooling (AN)
- Oil immersed Natural cooling (ON)
- Oil immersed Forced oil circulation Natural cooling (OFN)
2. Artificial Cooling (Air)
- Oil immersed forced oil circulation with air Blast cooling (OFB)
- Oil immersed air blast cooling (OB)
- Air blast cooling (AB).
3. Artificial cooling (water)
- Oil immersed Water cooling (OW)
- Oil immersed Forced oil circulation with Water cooling (OFW).
4. Mixed Cooling
- Oil immersed Natural cooling with alternative addition air blast cooling (ON/OB).
- Oil immersed Natural cooling with alternative addition oil circulation (ON/OFN)
- Oil immersed Natural cooling with alternative addition forced oil circulation air blast cooling (ON/OFB).
- Oil immersed Natural cooling with alternative addition forced oil circulation and water t cooling (ON/OFW).