Because of AC 's advantages in long distance high voltage transmission, there were many inventors in the United States and Europe during the late 19th century trying to develop workable AC motors. The first person to conceive of a rotating magnetic field was Walter Baily, who gave a workable demonstration of his battery - operated polyphase motor aided by a commutator on June 28, 1879, to the Physical Society of London. Describing an apparatus nearly identical to Baily 's, French electrical engineer Marcel Deprez published a paper in 1880 that identified the rotating magnetic field principle and that of a two - phase AC system of currents to produce it. Never practically demonstrated, the design was flawed, as one of the two currents was "furnished by the machine itself. '' In 1886, English engineer Elihu Thomson built an AC motor by expanding upon the induction - repulsion principle and his wattmeter. In 1887, American inventor Charles Schenk Bradley was the first to patent a two - phase AC power transmission with four wires.
who produced the first motor that run on ac
Walter Baily