What is Slip of the Induction motor:
Slip is nothing but the ratio of the difference between the synchronous speed (Flux speed) to actual motor speed to synchronous speed. It is normally expressed in S
S = Ns-N/Ns
Where S is Slip.
Ns= Synchronous speed.
N= actual motor speed.
It depends upon two speed
- Synchronous speed of RMF Ns
- Rotor Speed (N)
Percentage of Slip is expressed as,
%s= Ns-N/Ns X 100 %
In terms of Slip, the actual speed (N) can be expressed as
N= Ns (1-s)————————-1
Equation 1 in two conditions, which means
- At start of the motor N=0
- Slip S= 1
- This is maximum value of Slip
- At Ns=N
- Which means Slip=0
This is never possible in induction motor at any condition.
Practically slip maintains 0.01 to 0.05. it means 1 % to 5 %
The Slip which is corresponding to the full load speed of the motor is called as Full load Slip