Flux is not controllable in Direct Torque Control of IM

[Ziya]

Hi all,

I was trying to simulate a direct torque and flux controlled induction motor in simulink.
Even though I've managed to control torque within the band, i can't seem to be able to control the flux.
It stays for a while within its hysteresis band and escapes after about 0.1 sec and keeps on increasing, and about 0.2 secs later torque escapes its own band ( I am presuming its because of the rapidly increasing phase current sustaining the increasing flux). The switching table is giving the correct output.
What could be going wrong. I am using the simulink models of igbt universal bridge and induction motor.
Help!

 

[Achy47]

Hi there,

Thank you for sharing your experience with us. It sounds like you have made some progress in controlling the torque, but are having trouble with controlling the flux. This can be a common issue in simulations, as it is difficult to accurately model all aspects of a complex system like an induction motor.

There are a few potential reasons why you may be experiencing this issue. One possibility is that there may be a problem with your model or simulation setup. I would recommend double checking all of your parameters and equations to ensure they are accurate and correctly implemented.

Another possibility is that the issue may lie with the control algorithm itself. Have you tried adjusting any of the control parameters to see if that improves the performance? It may also be helpful to review the literature on direct torque and flux control to see if there are any specific considerations or techniques that could improve your results.

Lastly, it may be worth considering using a more advanced simulation tool that is specifically designed for motor control applications. These tools often have more accurate and robust modeling capabilities, which could help you troubleshoot and improve your results.

I hope this helps, and best of luck in your simulations!