Electromachine Generator

a device that transforms the mechanical energy of rotation into AC or DC electrical energy. The mechanical energy is obtained from a primary motor (usually steam, gas, hydroturbine, or internal combustion). Sometimes an electric motor is used to turn the electromachine generator. In this case, the electromachine generator, together with the electric motor, serves to transform the type of current (for example, from DC to AC), or to transform electric current from one frequency to another.