stepper motor drives

[exam baba]

Hi,

I am developing a control system for the speed control of a gas turbine. So for that i need to change my present manual movement of the fuel valve to one by a stepper motor. The valve is very sensitive, so i need a high resolution stepper motor (100,00 steps per revolution). I have a NI CRIO and have a digital I/O module fit on the chasis. With the existing setup, i would like to know what is the best stepper motor i can get in the market with least modifications to my current setup. If such a thing is not available, then what is the next best choice. Can anyone please help me out on this.

Regards,

Umesh

[Jochen]

Hi Umesh,

could you please provide some more information? First I feel a bit uncertain by the resolution that you are looking for? Do you mean 10,000 steps per revolution or 100,000 (with a missing zero at the end)?

If it's 10,000 steps/rev, you could use a standard stepper motor (200 steps/rev) with x50 microstepping. If it's 100,000 you definitely will need a gear box. In general I would also recommend a gear box if you need 10,000 steps/rev, as x50 microstepping is already a quite high value, resulting in reduced accuracy (steps are not evenly distributed anymore).

Some other questions:

• Could you please provide information about the required velocity and acceleration values?
• What about the inertia of your valve? Any idea about motor sizing?
• Which cRIO digital I/O module are you using?
• Are you using NI Softmotion?
• Have you thought about using cRIO drive interface modules (makes programming much faster and easier)?
• Have you already decided which power drive to use?

Kind regards
Jochen Klier

National Instruments

[exam baba]

Hi,

I am using NI 9401 digital i/o module. I donot have specs relating to velocity and acceleration of the motor. I am not using NI soft motion.

[Jochen]

Hi Umesh,

for a proper motor sizing all the information that I have requested is really essential. What about the resolution (10.000 or 100.000 steps/rev)? What about the required motor power and the load's inertia?

I'm sorry, but I really can't help you without knowing these specifics.

Thanks,

Jochen

[Vaibhav_Vashisht]

Hello Umesh,

Here's a site you might find useful for deciding on which motor/drive to use for your application: http://in.farnell.com.

Regards,

Vaibhav.