"AC motor": used to implement and AC electric machines that convert mechanical energy. Due to the development of AC power system, AC motor has become the most commonly used motors. AC motors and DC motors, compared with no commutator (see DC motor reversing), simple structure, easy to manufacture, very stable, easy to make high speed, high voltage, high current, high capacity motors. AC motor power range is very large, from a few Watts to hundreds of thousands of kilowatts, or even millions of kilowatts. In the early 1980 of the 20th century, the largest turbo-generator at 1.5 million-kilowatt. AC motors [1] was invented by Serbian-American scientist Nikola Tesla.