Models and motors in ATP

[Alex68]

Hi friends,
is there anybody expert in ATP simulations?

I am starting now and I have many difficulties but the manuals are not clear.
I would like to simulate induction motors by UM3.
Two problems:

1) Enabling the manual initialisation of UM, I must input some currents, but there is no description about them. Enabling the automatic initialisation, a new terminal of the motor appears but there is not any description about it.

2) I would like to simulate a pump as mechanical load. its torque characteristic is a parabolic function of the speed.
since the angular speed is a voltage and the torque is a current, I shoud build a non linear component by the Models language. Despite my efforts, I cannot make it to work.

Could anybody help me?

thank you very much
Alex68

 

[Bung]

You could try one of the user groups, if you are a registered user with the necessary password and user name - talk to your local ATP coordinator type. The licence is VERY restrictive, and strictly speaking no registered user could reply to you here with examples etc (if my reading of the licence is correct)!

Bung
Life is non-linear...

 

[Alex68]

Hi Bung
I'm a registered user and I tried to ask to the user group but... the EEUG is organising a course to explain these matters in October in Norway.
The journey and the course are tooooo expensive for me.

thank you all
alex68

 

[MattMag]

Hi Alex,

The new terminal that appears is to specify the torque device (Type 14 Current source) that the auto-initialization routine will adjust the magnitude of. I've just started modelling UM3 and thats the easiest way I've found. Also found that the Neutral must be connected to Earth, using a large resistance if necessary.

I've not got to the stage of modelling load/speed variations - I would do it using TACS (cos I've never used models !) as a first guess I would use a TACS function to change the IM speed to the correct torque then interface this with the Type 14 source - not sure how to do this, but you might be able to define an ATP variable type, then modify from within TACS.

Sorry this is not definite help - Let me know how you go, I'll no doubt have to do a similar thing at some point.

Matt

 

[Alex68]

Hello MattMag,

Thanks for the information that the autoinitialisation adjustes the current source magnitude. But I must insert also a resistor (1e-6 ohms) between the two lower pins (=terminals).
The simplest way to obtain a parabolic load torque is to use a non linear resistor and input the characteristic point by point. The pro is the simplicity, the contro is that ATP consider a simmetrical monotone curve for negative speeds. So the pump becomes a turbine!

The work is in progress...