That is to say, as long as the position of any two power lines in the three-phase motor is changed, the rotation direction of the three-phase asynchronous motor can be changed.
Extended data:
principle of operation
When symmetrical three-phase alternating current is applied to the three-phase stator winding, the rotating magnetic field rotates clockwise along the inner circular space of the stator and rotor at the synchronous speed n 1. Because the rotating magnetic field rotates at the speed of n 1, the rotor conductor is stationary at first, so the rotor conductor will cut the stator rotating magnetic field and produce induced electromotive force (the direction of induced electromotive force is determined by the right-hand rule).
Because both ends of the rotor conductor are short-circuited by short-circuit rings, induced current will be generated in the rotor conductor under the action of induced electromotive force, which is basically consistent with the direction of induced electromotive force. The current-carrying conductor of the rotor is acted by electromagnetic force in the stator magnetic field (the direction of the force is determined by the left-handed rule). The electromagnetic force generates electromagnetic torque on the rotor shaft, which drives the rotor to rotate in the direction of rotating magnetic field.
Through the above analysis, it can be concluded that the working principle of the motor is as follows: when three-phase symmetrical alternating current is applied to the three-phase stator winding of the motor (the electrical angle difference of each phase is 120 degrees), a rotating magnetic field will be generated, which will cut the rotor winding, thus generating an induced current in the rotor winding (the rotor winding is a closed path), and the current carrier conductor will generate electromagnetic force under the action of the stator rotating magnetic field, thus forming electromagnetic torque on the motor shaft and driving it.
Baidu Encyclopedia-Three-phase Asynchronous Motor