How to model the three-phase short-circuit in a Brushless motor?

Ciro Alosa_21513

Hi everyone,

I would like to simulate the short-circuit of a brushless machine and obtain the maximum d-axis current to run demagnetization.

 

I saw a tutorial but I can't find it anywhere.

 

 

Farid zidat_20516

Hello Ciro;

 

you can make a 3 phases short circuit as described bellow:

 

Please take care to make a [Valid] function to modify the resistance value from 1E-4 to 1E4 when you switch on at time t (for instance here t=0.2s).

Then you can expect a current on the coils like bellow:

Which tutorial you are talking about ?

 

Regards  

Farid zidat_20516

I forgot to ask you which short circuit you want to have, bi phase or three phase ?

Ciro Alosa_21513

Thank you Farid. 

Yes I want to model the three-phase short circuit.

 

If I have a brushless motor with imposed currents with current generators, do I have to use the resistance as well?

 

Regards

Farid zidat_20516

You are wellcome !

It is better to use voltage sources, otherwise you to think how to insulate the current sources from the motor coils. I mean in this case instead of using resistances as shown previously, you have to use switchs in order to connect the current sources to another set of resistance for instance. This is to avoid the current sources to continue to supply the short circuit.

 

Regards 

Ciro Alosa_21513

Farid zidat_20516 said:

You are wellcome !

It is better to use voltage sources, otherwise you to think how to insulate the current sources from the motor coils. I mean in this case instead of using resistances as shown previously, you have to use switchs in order to connect the current sources to another set of resistance for instance. This is to avoid the current sources to continue to supply the short circuit.

 

Regards 

Would it be possible, as a workaround, to impose a zero current at the current sources when the fault happens?

Farid zidat_20516

Ciro Alosa_21513 said:

Would it be possible, as a workaround, to impose a zero current at the current sources when the fault happens?

Hello Ciro;

 

Yes this is something you can try of course. 

 

Regards