Resonance in a 400v AC circuit

[rune haferkamp]

Hello.

So me and some friends build a cable model(a pi-equivalent) for testing of a asynchronous induction motor(0,37kW). The powersupply is 400V AC.

Included some pictures of the model and the 1 phase equivalent.


My question is: Let's say the motor has been running at 1480 rpm for some time. What happens when the power is turned off? Will there occour any resonans, and if so, is it possible to calculate? I guess the biggest impace will be the inductors... Im really confused by this problem.

Any help would be very nice!

sorry for the bad writing.

 

[dr pepper]

Oops I misunderstood that one.

 

[ronsimpson]

Do I have the right values? I was not certain on the capacitors.
This filter wants to "ring" at 500hz and 1.4khz.
Is this what you see?

 

[schmitt trigger]

Is the power turned off right at the motor terminals fully disconnecting it? Or at the transformer, which means that you leave a rotating motor connected?

The later is far more complex, as you would have to take into account the motor's electrical and mechanical characteristics as it slows down.

BTW, I like the photos of your setup. Is this a school lab?

 

[rune haferkamp]

Thanks for the reply guys!

Yes, it is disconnecting right at the transformer, so the rotor runs for a small amount of time after shutoff.


Yes, we build it at school. Its for our thesis