Section 15.4: Performance Calculations cont.
The electromagnetic (developed) torque Te of the motor is its total developed (mechanical) power 3Pd (for all three phases) divided by the motor’s shaft speed wm
\ Te = 3Pd /wm. However, wm = (1 - s)ws, where ws is the synchronous speed and Pd = (1 - s)Pg
Ergo, Te = 3Pd /wm = 3(1 - s)Pg / (1 - s)ws \ Te = 3Pg /ws