Question

Step up transformer application in substation

Answer 1

Power is generated at the relatively low voltage and is transferred at the higher voltage for efficiency reasons. If you transfer power at the higher voltage, efficiency of the transmission increases. The generated voltage is not equal to that much higher voltage and hence the “step up” transformer is used. It steps up or boosts the voltage to a higher value to facilitate the higher voltage transmission. Transformation depends upon the turns ration of the windings.
Np/Ns=Vp/Vs=n

 In power plant, this transformer is used as connecting transformer of the generator to the grid.

Thanks.