Dyamic braking in induction motors

[Kal_B]

Hell guys,

I understand in the most general sense how a motor works and production of torque and that when the rotor turns faster than the rotating magnetic field "it runs into a generator". There are thousands of articles stating that much but not exactly how turning into a generator explains "braking".

From bits an pieces I gathered that the rotor going faster than the magnetic field will cut the magnetic field in such a way as to produce torque in the opposite direction. My questions:

• Is that accurate.
• If accurate then it will be according to the right hand rule of magnetic field and force?
• I would love to see animation or illustration that show flux, current, force etc.

Thanks

 

[MaxHeadRoom78]

Braking of an induction motor is typically done with a method using DC injection.
Max.

 

[unclejed613]

when a motor is spun by it's shaft, and instead of power being applied at the motor terminals, the power is dissipated in a load, the motor acts as a generator, and as power is dissipated in a load, it creates a back-torque in the armature which brakes the shaft. you can see this action for yourself with a stepper motor. with the drive wires disconnected, as you spin the shaft, you will see an AC voltage appear across the windings, the motor is acting as a generator, and with no load is easy to turn. if you tie all of the wires together electrically, and now try to spin the motor, it's difficult, because most of the power you are applying is being dissipated in the low resistance of the windings and the connecting wires.

 

[MaxHeadRoom78]

. if you tie all of the wires together electrically, and now try to spin the motor, it's difficult, because most of the power you are applying is being dissipated in the low resistance of the windings and the connecting wires.

You will only experience that if a magnetic field is present, P.M. DC or BLDC motors, not on a AC induction motor.

DC injection braking - Wikipedia

en.wikipedia.org

Max.