Electromagnetic speed regulation

I don’t quite understand it and haven’t used it before. It should be DC rotor excitation speed regulation.

The electromagnetic speed-regulated asynchronous motor is composed of an ordinary squirrel cage asynchronous motor, an electromagnetic slip clutch and an electrical control device. The asynchronous motor is used as the prime mover. When it rotates, it drives the armature of the clutch to rotate together. The electrical control device is the device that provides the excitation current of the slip clutch excitation coil. It consists of three parts: armature, magnetic pole and excitation coil. The armature is a cylindrical structure made of cast steel. It is connected to the rotating shaft of the squirrel cage asynchronous motor and is commonly known as the active part. ； The magnetic pole is made into a claw-shaped structure and is mounted on the load shaft, commonly known as the driven part. There is no mechanical connection between the active part and the driven part. When the excitation coil passes current, a magnetic field is generated, and the claw-shaped structure forms many pairs of magnetic poles. At this time, if the armature is dragged to rotate by the squirrel-cage asynchronous motor, it will cut the magnetic field and interact to generate torque, so the magnetic poles of the driven part will rotate together with the active part armature. The rotation speed of the former is lower than that of the latter, because only when the armature and the magnetic field are in relative motion, the armature can cut the magnetic lines of force. The principle that the magnetic pole rotates with the armature is not essentially different from the principle that the rotor of an ordinary asynchronous motor moves with the rotating magnetic field of the stator winding. The difference is that: The rotating magnetic field of the asynchronous motor is generated by the three-phase alternating current in the stator winding, while the magnetic field of the electromagnetic slip clutch is generated by the DC current in the excitation coil, and plays the role of the rotating magnetic field due to the rotation of the armature.