DC motor has the advantage of quick react, bigger starting torque and provide rated torque between 0 and rated rotation speed, but its advantage is also its disadvantage, because DC motor need to generate constant torque under rated torque, it will need commutator and carbon brush. But commutator and carbon brush will cause spark and carbon powder during motor rotation,it will damage the motor components and has the limit of application.

AC motor has no carbon brush and commutator, no need maintainence, hard and been used widely. But it will need complicated controlling technology if need to achieve the similar performance with DC motor. There are two types of AC motor: asynchronous motorand synchronous motor. There are three types ofasynchronous motor as per the stator phase number: single phaseasynchronous motor, two phaseasynchronous motor and three phaseasynchronous motor. The structure of three phaseasynchronous motor is simple, reliable and lower cost.