1. Three-Phase Induction Motor Stator

2. Three-Phase Alternating Current

3. Rotating Magnetic Field

4. Induction Motor Parameters Synchronous speed, n s –speed of the rotating flux –frequency of the applied voltage = f s –number of poles = P poles occur in pairs, P/2 –n s = (120)(f s )/P r/min

5. Induction Motor Parameters (cont) Slip speed, n –The difference between the speed of the rotating flux and the speed of the rotor –n = n s - n r Slip, s –The ratio of the slip speed to the synchronous speed –s = (n s – n r )/n s