1. When the weight of the crane drops, the rotor of the […]
1. When the weight of the crane drops, the rotor of the motor is manually operated under the gravity of the weight, and the speed of the rotor may exceed the synchronous speed. At this time, the motor is in the regenerative braking state. At this time, the braking torque of the motor prevents the falling of the heavy object, and the weight stops falling when the braking torque and the torque formed by the gravity are equal.
2. When the frequency conversion is adjusted, when the frequency converter reduces the frequency, the synchronous speed also decreases. However, due to the inertia of the load, the rotor speed will not decrease immediately. At this time, the motor will also be in the regenerative braking state until the speed of the drag system also drops.
The working principle of the motor: the motor uses electricity and magnetism to convert each other to convert electricity into magnetism (the stator windings play this role), and then the rotating magnetic field is generated by the stator windings, and the generated rotating magnetic field cuts the rotor bars due to the rotor guide. The strip is in a short-circuit state, so a large current is generated, and then the current generates a magnetic field, which rotates under the interaction of the stator magnetic field and the rotor magnetic field.