A power transformer is a piece of stationary electrical equipment designed to transform alternating voltage (or current) at a specific value into voltage (or current) at one or more different values, while maintaining the same frequency.
It is a stationary device with two or more windings that, for the purpose of transmitting electrical energy, converts alternating voltage and current from one system to those of another system at the same frequency via electromagnetic induction; typically, the values of the voltage and current differ between the systems.
