Hello,

I am studying the working principle of an induction motor. The attachment is a portion from Stephen J. Chapman's textbook (page 160-169). He proved the theory of the rotating magnetic field so well for a 2-pole induction motor from 160 to 164. However, on page 166, the author proposed a 4-pole motor but did not provide the similar proof. I would like to know how this configuration forms a rotating magnetic field and makes the rotor (squirrel cage) rotate. Do you guys have any good papers for this?

Thank You
BlackMelon

 

Both 2pole and 4 pole motor operate on exactly the same principle, with the introduction of 2 more sets of poles, the mechanical time taken between them is halved, therefor the 2 pole motor rotates at twice the rate of the 4 pole, 6 pole and 8 pole will reduce the rpm in the same manner at a corresponding rate.
If you understand the 2 pole, the rest should follow..