An electric power transformer is a static electrical device used to convert an alternating voltage (current) of a certain value into one or more voltages (currents) of different values at the same frequency.A static device with two or more windings, in order to transmit electrical energy, converts the alternating voltage and current of one system to the voltage and current of another system at the same frequency through electromagnetic induction. Usually, the values of these currents and voltages are different.