Section 15.2: Slip
The synchronous speed is: ns = 120f/p = 120´60/6 = 1200 RPM
The rotor speed is n = (1 - s)ns = (1 - 0.04)´1200 = 1152 RPM
fR = sf = 0.04´60 = 2.4 Hz.
The speed of the rotor field with respect to the (rotating) rotor structure is nRf = 120 fR /P = 120 (sf)/P = sns = 0.04´1200 = 48 RPM
The speed of the rotor field with respect to the (stationary) stator structure is n + nRf = (1- s)ns + sns = ns = 1200 RPM (i.e., the rotor and stator fields rotate together)
A six-pole three-phase 60 Hz induction motor runs at 4% slip at a certain load. Calculate: the synchronous speed, the rotor speed, the frequency of the rotor currents, the speed of the rotor field with respect to the stator and speed of the rotor field with respect to the stator field.