you can use state space equation for the IM model , then convert these equations into simulink model as inputs and outputs.

use different variables to control speed and torque

Go through the d-q modelling of induction motor. You can refer "

Analysis of Electric Machinery and Drive Systems" by P. C. Krause for modelling of Induction motor. Just make the model of Induction motor and the control can be applied to it externally. You don't need to model the control part with the Induction motor.

Dear Mr Michael Simonovski

Please use this link which directs you to the matlab forum. It will be of help to you.

https://in.mathworks.com/matlabcentral/fileexchange/32814-induction-motor-modeling?s_tid=srchtitle

regards

Rajesh Kumar J

Hello, Michael!

There are a number of articles and books dedicated to induction motor control and simulation. For sure, you have to separate terms of "induction motor (IM)" and "control system". If you want to plot Torque-Speed characteristic of IM, you have to simulate IM with its nominal parameters connected to the sin(cos) sources with amplitude and frequency nominal for the IM stator.

If you used the IM model correctly, the speed could have decreased from the beginning due to load torque exceeding the start torque of IM. Try to no-load start of IM (without load torque) or to increase amplitude of the stator voltage (it leads to start torque increasing).

You didn't mention the features of "decreasing speed from the beginning" but you can also try to change two phases of sources (it leads to the reverse of IM).

Just in case, I attached some model of IM in Matlab Simulink.

Best wishes and good luck!

I've tried to remake the model from the photos you've posted. But i have the same results, which i had with another im simulink models.

Unfortunately i couldnt understand your stator voltages tranformation, because of the not described Gains, so i mace it as i knew with the consideration of the angle of the rotor.

I upload my model if you want to see it

Dear Mr. Pugachev,

i tried your Simulink model with your values and that is the diagramm i am looking for.

Unfortunately i have specified values from the manufacterer of the induction motor (yellow marked). I tried several models with this values (also yours) and had as the result an error. I think this errors could hang together with the values i have.

Are there another possibilities to calculate the values (resistance, inductance, etc.) without experiments?

Hello, Michael!

I attached the model with your parameters, it works for now. You misfit the values of stator and rotor inductances. In this equations you have to use instead of L1σ and L2σ the next expressions: L1=L+L1σ and L2=L+L2σ. It means that in your case it will be as following: L1= 0.0809+0.0026 (H) and L2= 0.0809+0.0031. Some theory about this is considered in the article attached.

Also, I noticed that the J of your motor is small and relation between Te and Tm (electromagnetic and mechanical constants) causes the oscillations of both torque and speed. so I recommend you to increase J to mitigate excessive oscillations.

I hope my answer is useful and it helps you to understand the interesting world of electric motors and drives.

Best wishes and good luck!

Article Two induction motors electric drive with rotatory stator