Similar to three-phase asynchronous motor. The rotor of the motor is stuck have been magnetized permanent magnet. In order to detect motor rotor polarity, in the motor with position sensor. The driver is composed of power electronic devices and integrated circuits, the function is to accept the motor starting, stopping, braking signal, to control the motor start, stop and brake, to accept the position sensor signal and positive control signal, to control the inverter bridge each power tube of the pass, to produce a continuous torque; accept speed and speed feedback signal, to control and adjust the speed; provide protection and display, etc..