Demo model "Vector Control of an Induction Machine"

Question

Dear plexim team

I am not sure if I understand the equivalent circuit in the demo model "Vector Control of an Induction Machine" correctly (see attachment). I only know the static equivalent circuit per phase (see attachment). Have I correctly interpreted the relationships between the simulation parameters in the demo model and the static equivalent circuit?
Rs = Rs
Rr = Rr
Lls = L_sigma_s
Llr = L_sigma_r
Lm = Lh
Is Rfe being neglected?

Thanks for your help.
Greetings,
Raphael

Answer 1

Raphael,

There is a difference between the models you're showing.  As you suggested, the "Static Equivalent Circuit" you're referring to is a per-phase equivalent circuit in steady state based on motor slip. The circuit model in the demo model is in the DQ reference frame aligned with the rotor flux.  Lastly, the PLECS machine model is actually implemented in the alpha-beta reference frame.

However, in the initialization script you can see the equivalent model parameters from the PLECS machine model to the DQ reference frame aligned with rotor flux equivalent model.  For example, refer to the calculation of "Lsigma" and "RR" or "Rtot".  You are correct in that Rfe is neglected in both cases.

Thanks,

Bryan

Comments

Hello Bryan

Thanks for your reply.
That is, the conversion from PLECS machine model in DQ reference frame aligned to the rotor flux equivalent model is done within the simulation parameters.

On a real machine, using an open circuit measurement and a short circuit measurement, I can determine the equivalent circuit parameters of the static equivalent circuit per phase. How do I calculate the parameters of the PLECS machine model from these parameters? Do I have to convert them at all or are they the same? The two equivalent circuit diagrams are again attached to the appendix.

Thanks for your time.
Greetings,
Raphael