There are many reasons to employ power transformers in electrical power networks. But one of the essential reasons to use this device is to reduce power loss during power transmission applications.
Now let us see how the wastage of electricity is reduced by employing power transformers:
First, the equation for wastage of electricity is
P = {I}^{2} RP=I2R
Here I is the currents across the conductors, and R is the resistance of the part.
So, the power wastage is directly related to the class of current going across the conductor or transmission line. So, the smaller the magnitude of the current flowing within the conductor, the lesser the power wastage. How we will take advantage of these phenomenons is discussed below:
Take the starting voltage is 100V, the load draw is 5A, and the power delivered is 500 watts. Then here, the transmission system should draw a current of magnitude 5A from the supply to the load. But if we increase the voltage in the first section to 1000V, the transmission system should only take 0.5A to deliver the same power of 500W.
Therefore, we will increase the voltage at the primary stage of the transmission system by using a power transformer and employ a second power transformer to reduce the output at the end of the transmission network.