Adding Magnets to Induction Motors

I gather that you want to turn an induction motor into a generator by adding magnets and spinning it by mechanical means? In principle, certainly. I would strongly suggest you buy a St. Louis motor kit, and do some experimentation with that. It's a lot of fun and you'll really get a chance to see how you can turn a simple motor into a generator by adding bar magnets, and so on.

You can buy a new one, already perfect, here, you can probably find one on e-bay, or you could make your own from scratch (and really learn the principles!).

Good luck.

This will certainly will not help and might reduce the efficiency of any use of an induction motor as a motor or generator. You see, the magnetic field generated in the rotor is induced (hence the name) by the rotating magnetic field generated by the stator windings. So adding a fixed location permanent magnet to the case that houses the stator windings will not assist the formation of the rotating magnet field. The most that this added fixed location field can do is make the rotating field's magnitude non-uniform as it rotates, but even this is not very likely. The only way I can see this happening is if the magnetic flux density is already so close to saturating the magnetic core material of the stator that the permanent magnet fields added flux starts to saturate the core. Few motor designs run this close to the saturation of the core, but without knowing the induction motor or the permanent magnets in question I cannot rule this out.

Adding magnets to the outside of the motor will not help much in producing any power (as Generator, if this is what you are saying). The Magnets must be on the rotor so that when the rotor is spun, the magnetic field will be sweeping the windings of the stator to generate any power...(I presume you have a squirrel cage Induction Motor).

How practical this is going to be depends on how much skill you already have to be able to modify the rotor properly, removing the effect of the squirrel cage, balancing the rotor, finding the suitable sized magnets etc.

the Magnets on the outside will have negligeable influence for the purpose seeked, and the effects are not easily predictable just by anybody without details of the motor. In any case, not useful.

There are principles guiding these motors. In the three phase induction motor, three phase supply must be present to enable the rotation magnetic field lock and pull the rotor along.

In the above case, an additional permanent magnet placed on the motor casing will cause severe distortion of the balanced magnetic field and will cause an unbalanced pull/torque on the shaft.

For a single phase motor with capacitor start or run, a good and efficient pair of magnet(north & south) poles places on the outer casing of the motor will effectively improve on the speed of the motor (sooth speed). The magnets must be placed between the reference field and the capacitor current field.

By moving the pair magnets around the motor casing, a suitable angle will be reached where the permanent magnet fields will interact positively with the stator fields to effect excellence rotation of the shaft.

Note: The magnet must be polarised and 1 pair for a 2 pole induction motor, 2 pairs for a 4 pole induction motor. All single phase motors.

Dickson .