Slip in Induction Motor
The voltage induced in rotor bars of an induction motor depends on the speed of rotor with respect to the magnetic fields. The term slip in Induction motors is used for representing the relative speed of rotor with respect to magnetic fields.
Mathematically formula to calculate
Slip (s) = [ ηsync – ηm ] / ηsync
where
ηsync = Speed of magnetic fields
ηm = Speed of motor shaft
The factor on the right side is often multiplied with 100 to represent slip in terms of slip percentage.
Slip %age = {[ ηsync – ηm ] / ηsync } * 100
Important points to remember
- The rotor of an induction motor always turns slower than the synchronous speed, so the slip and slip percentage is smaller than 1 and 100 respectively
- Slip is actually the difference between synchronous speed and actual speed