We know that torque in an induction machine varies as \$k\times[\cos(2wt)+\cos(\beta)]\$ but we don't feel it. Why it's so?

  • \$\begingroup\$ Is that formula correct? I have not formally studied induction machines, but it was my understanding that the torque was proportional to the slip. \$\endgroup\$
    – user57037
    Commented Apr 2, 2015 at 6:20
  • 1
    \$\begingroup\$ @mkeith, it is proportional to slip in a running, loaded induction motor. I didn't check the equation, but it looks really familiar. There are instantaneous fluctuations in torque based on when the poles of the rotor and the stator cross, though, but under any kind of load - including the rotor - they are usually inconsequential to anyone except the team that had to design the machine. \$\endgroup\$
    – user39962
    Commented Apr 2, 2015 at 7:07

1 Answer 1


Evaluate that for 60 hz on an actual machine. Account for the rotational inertia of the rotor mass. Consider that momentum is like a bucket - if you add a drop and lose a drop 60 times a second, nobody is going to see the level change unless they are really looking for it.


Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Not the answer you're looking for? Browse other questions tagged or ask your own question.