Hi all,

I am working on a 3 phase AC servo motor . I am using current sensors to measure the current from each phase of the motor, let say: i_u, i_v, i_w.

I want to track the motor torque using these measurements. Is there ay way to do that?

Also, how can I get a total RMS current? Is it I_rms = sqrt(i_u^2+ i_v^2 + i_w^2) ?

Thank you so much!

 

see http://www.elliottelectric.com/Stat...erences/Calculations/Electrical_Formulas.aspx

736Watt = 75 Kg in one second lifted one meter.

This all allows you to calculate the torque.

Picbuster

 

Thank you for your suggestion.

But what I want is the instantaneous torque of the motor in operation when I control the motor to move in different profile. What I have are only the instantaneous 3-phase current I measure from the motor wires. I don't know the voltage and the efficiency.

Micheal

 

This PDF, AC Permanent Magnet and PMDC Brushless Servo Motor Parameters and Conversions gets into torque factors around page 4, it may help you out a little. Also is the 3 phase motor wired as a delta or wye configuration? Finally, and this is far from my forte, what is the motors HP rating and HP rating? Finally these charts and formulas from Leeson may help.

Ron