why typical speed is always lower

ELEC 343, $25, M8 Speed of a P-Pole Motor Recall P-pole Stator System (P - number of magnetic poles) de = Wt Electrical displacement P Wsyn n syn Typical rad/sec| rpm speed, n Electrical (stator) speed for fe = 60 Hz rpm We = 2nfe ~ 377 [r/s] 2 120n 3600 3520 Synchronous speed is 2/P of the 4 60T 1800 1750 electrical speed 2 We [r/s ] 6 40n 1200 1160 @ syn S P 8 30T 900 830 120 12 20pi 600 570 n syn = fe [rpm] p P Electrical (Referred) and Mechanical @, = -Wrm Or = Orm speed position 2 2 We can always "convert" a P-pole motor into an equivalent 2-pole motor using the P/2 factor ! 16