Effect of load on the tangential-force pulsations and harmonic torques of squirrel-cage induction motors

A method is given for the determination, on load, of the influence of slot combination on the tangential force pulsations and harmonic tooth-ripple components of torque that arise in induction motors. The method of conformal transformation and a surface integral method are used to obtain the tangential force acting on any stator or rotor tooth for any rotor position. The tangential force pulsations and the harmonic tooth-ripple torques are computed, for a given stator slot number and for a range of rotor slot numbers. Conclusions are drawn about the choice of slot combination.