Induction motor parameter determination.

[BigLe]

Hi,

I need to measure all the parameters of an induction motor(squirral cage). While I found some standards on Nema and Ieee, they are not that straight forward. Any one gets links or documents that describes a "standard" proceedure to do the measurements? ( Rr, Rs, Lr, Ls, M ) .. thanks in advance..

BigLe

 

[aolalde]

The straight method I know is IEEE Std 112 Test procedure for Polyphase Induction Motors and Generators. This is not an ease task.

 

[KIMATEK]

I don't know if you are trying to get this data to tune the VFD (variable speed drive). However, if so, there are drives that comes with standard auto-tuning of the motor. This feature allows you to test the motor via the drive auto-tuning function in order to obtain the electrical model of the induction motor you are tying to find out (Rs, Ls, Tr, etc..)

kimatek.com

 

[ijl]

An estimate of the main electrical parameters can be obtained in the following way:

Find the voltage, (electrical, useful) power, slip, power factor, efficiency and the ratio of locked rotor current to nominal current of the motor.

Use the (well known equivalent circuit of the motor. Write equations for the power, power factor, efficiency and the ratio of the currents using the impedances of the equivalent circuit. Express the impedances of the equivalent circuit using the inductances and resistances of the windings. Solve the equations for the inductances and resistances. (Assume Lr’ = Ls, for example).

Not an easy task? See

http://pp.kpnet.fi/ijl/prog.htm

for some help.