problem in simulating induction motor

hello everybody, currently m facing a problem in working with simulink.i am trying to make an induction motor model in simulink.i am triyng to measure the air gap power and the gross mechanical power.....but strangely the slip is coming zero and the two above mentioned powers are equal in magnitude....m using the equvalent circuit model of the induction motor and when i tried to measure the voltage across the rotor its showing zero value...i have attached the picture of my model below....help me pls...!!!!thanks in advnc

[aratrik]

please guys.....hlp me solve this problem!!!!

Answer 1

[MC]

I think you have a dq model implementation. If so, you need to have both q- and d-axis models implemented. Also remember that your voltage source frequency depends on the frequency of rotational reference frame, and probably in your case it is dc (zero frequency).

[aratrik]

in case of an induction motor there is no such d q axis......i have only simulated the equvalent circuit and calculated the powers.....i used simple elements like resistance and inductance as u can see and implemented the formulae for calculating the powers....in that case it becomes a simple circuit solution i guess.....slip is coming zero coz the airgap power and mechanical power are same in magnitude ....this is because which is the main error as the voltage drop across the r2'+x2' is zero...but how this is possible i dont know

[aratrik]

i have tried measuring current in other branches too with that spare current measurement box but in every case the calculated power becomes different