which rotor velocity should I use to calculate the slip? Wm or Wr?

Hi,

When using the asynchronous machine SI block of Simulink which rotor velocity should I use to calculate the slip?

slip =(Ws-Wm)/Ws

or

slip =Ws-Wr/Ws Where Wr=(pair poles) * Wm

If I the second option the slip usually results in high values. Is this normal?

Answer 1

[Ahsan Rizvi]

first one is true since ws - wm = wr which is slip ,where ws = sychronous speed of stator magnetic field and wm = shaft speed