Nikola Tesla, an Austrian-American electrical engineer, designed and built the first alternating current (AC) induction motor. At the time of his invention, direct current (DC) was employed for electrical devices. Direct current flows continuously in one direction, but it was inefficient and could not deliver electricity over distances longer than 2 miles. Alternating current or a polyphase system, Tesla showed, could be delivered in either direction and it could be stepped up to vary high voltage levels over longer distances. This polyphase system revolutionized electric power distribution and this system was used to design the hydroelectric plant at Niagara Falls in 1895.
|Graphic representation of a polyphase system (three phases) that is indicative of alternating current. |
Graphic by: J JMesserly
To learn more about Nikola Tesla read here http://www.teslasociety.com/biography.htm