Basic Information About Electrical Transformers

By Author: Brilltech Engineers
Total Articles: 8
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The device that transfers electrical energy from one circuit to another for transmission purposes is known as electrical transformer. It is used to increase or decrease the power level. These are broadly classified into two categories one is step up and other is step down. The step up mode is used to increase the voltage level and step down configuration is used to decrease the voltage level. These are widely used in various industrial applications for transmission and distribution of power from one station to other. As voltage is transmitted at very high level in order to minimize losses, so it is essential to lower down its level with the purpose of using it for applications. These are widely used in applications like computer devices, television sets, CD players, industrial machines, manufacturing machines and many more.

Whatever be the application, the basic working principle of this remain same. It works on faraday law of mutual inductance. According to faraday law, time varying magnetic field induces current in the conductor. The same law is applicable in the working of transformers. In simpler language, time varying ...
... current in the primary winding changes the magnetic flux in the core material which induces current in the secondary. This principle of mutual inductance is applied in their working.

The ideal transformers comprises of basically core, winding & cooling.

Core: To create core highly permeable material is used in order to offer low reluctance path to the flux. Or we can also say that to avoid losses highly permeable material has to be employed while manufacturing cores. Laminated silicon steel is the most popular material is it has very high permeability as compared to free space or air. The thickness of lamination also plays an important role. The thickness has been reduced from 0.5 mm to 0.25 mm. The laminations are coated with layer of insulating varnishes, oxide or phosphate.

Winding: This is an integral part of any transformer. The one which is connected to the voltage is known as primary winding and the second where induction takes place is known as secondary winding. The number of turns in these are basically depends on the application whether we are stepping up the voltage or stepping down the voltage. Hence these are technically designed as high voltage winding & low voltage winding. The high voltage winding has more number of turns as compared to low voltage winding. Copper wire is generally used for this purpose.

CoolingAspects: In dry type configuration, simple air cooling is provided. There rating is few kVA. For higher rating, oil is used for cooling purposes. Technically it is known as oil & natural type cooling. In force is applied in this method then it is known as oil forced blast cooling.