Motor Identification for Asynchronous Induction Motors ACI

Here is the nameplate image from

Marathon Electric part number: 56H17T2011A

Parameters that are required in user.h when using the FAST observer and InstaSPIN solutions

POLE_PAIRS is straightforward.  It is Poles / 2.  This is only "required" so that the RPM and Torque values returned from FAST are correct, as all internal calculations are done in Hz. 

the no load current supplied on the nameplate is typically equivalent to the magnetizing current required. However this value is usually in RMS, while we need the amplitude.

MAGNETIZING CURRENT = i * sqrt(2) = 0.7 * 1.41 = 0.9899 A

#define USER_MOTOR_MAGNETIZING_CURRENT                   (0.9899)

Our RATED_FLUX value is actually the rated rotor flux.  So we need to calculate the rated stator flux and then subtract the flux produced by the inductance.

FLUX_STATOR_RATED = [sqrt(2)/sqrt(3) * (Vline-line / (2pi*f))
                                             = [ (1.411 / 1.732) * (230 / 2*3.14*60)]
                                             = [0.8146 * 0.6099]
                                             = 0.4968 Wb

FLUX_ROTOR_RATED = FLUX_STATOR_RATED - (Ls * Is-rated)
                                            = 0.4968 Wb - (0.0351 * 0.9899)
                                            = 0.4621 Wb

USER_MOTOR_RATED_FLUX = 2*pi* FLUX_ROTOR_RATED  (to convert to V/Hz)
                                                         = 2*pi * 0.4621
                                                         = 2.904 V/Hz

Thanks, Chris. That looks very useful.

Could you also write how to get Rr value (R1,R2,X1,X2,Xm) in case we don't have this ohm/phase table? You can presume all standard equipment is available (LRC meters, power supply, oscilloscope, or even a network analyzer).

you will be able to identify Rr with the latest MotorWare _12 once we release. 

dear, 

please can you give us the nameplate image for Marathon ACI GE 5K33GN2A?

thanks

I'm not in the office. I'll see if I can find one of these motors tomorrow...but if you have this motor don't you have the nameplate?  Have you tried google to see if you can get the datasheet which should have at least the nameplate terms?

thanks for reply,

i have the motor but the nameplate without the parameters of the motor!!!!!

i waite your reply

thanks

i'm sure my nameplate would look the same as yours. I suggest you do some googling to see if you can find the nameplate parameters/datasheet. I'll see what I can find tomorrow.

Just trying to get up to speed with Instaspin (excuse the pun!) when I saw this posting. Are you saying that the motor parameters identified by FAST and code in ROM are correct but that some interpretation of these by some GUI is incorrect? Or what?

R

I'm not having luck findind any useful data. My nameplate is the same as yours, doesn't have the information necessary.

I found from a Marathon catalog that the motor is also sold in a diferent packaging with PN:

48T17D2000

that led me to this site, but the datasheet is worthless as well

http://www.temcoindustrialpower.com/products/Three_Phase_Motors_with_Base_Mount/M16541.html

Roger,

For Induction motors the motor parameter ID process - in ROM - is flawed.  Or at least it doesn't support enough induction motors.

We are correcting this by updating some of the settings/parameters during the identiciation process. We already do something similar for low Ls / low flux / high speed motors with a special project: proj_lab02c, that we introduced in MotorWare _08 I believe.  The induction motor ID project will be added in MotorWare _12, which comes out in the next weeks.

What this post explains is how you can calculate all the needed parameters for induction motors if you have a thorough nameplate.  This was to help customers who wanted to run their ACI motors and were not successful with the existing Motor ID.

Thanks for this. Hopefully the location in the new version of Motorware where this can be found will be easy to find?

I see in code several references to FAST V1.6 needing some sort of workaround. Its probably under my nose but where can I find documentation on this?

R

Yes, it will be noted in the release notes and if you navigate MotorWare using MotorWare.exe it will be obvious.

FASTv1p6 is what is in ROM on the F2806x devices only.  There is a ROM bug regarding loading the Ls values from user.h into the control system. This is patched in every proj_lab##.c by the function:

#ifdef FAST_ROM_V1p6
void softwareUpdate1p6(CTRL_Handle handle)

This was fixed in FAST_ROMV1p7 which is in F2802x devices (and other devices coming soon).

thanks

an update for you induction afficianados:

Enhanced motor ID for AC induction motors is included in MotorWare _12 which will be released mid next week.  It is included in the standard labs, so you should be able to go to proj_lab2a and have success.

This is working extremely well with all motors we've tested on the TMDSHVMTRINSPIN kit.  However, there are still some low inductance ACIs that would normally be used with DRV83xx kits (low voltage, typically higher current) that are still giving us ID issues.  We plan to solve this for MotorWare _13.  Just hang in there with us :)

Most of motor name plates just have the rating currents and voltages with poles, no indication for Rotor Resistance and Inductance and any other parameters ? so what're your recommendations ?

Most ACI motors can now be identified using proj_lab2a/b in latest MotorWare.

We are still having issues with specialized ACI (very high speed, typically low Ls)

Could you please clarify more about those issues as I am about to start developing variable speed driver for a certain types of pumps using your MotorWare ? 

Is there any more info about using it with Induction motors?!

Amr,

The SPRUHJ1 InstaSPIN User's Guide has all of the detailed information, and inside MotorWare is MotorWare.exe where you will find the Project & Labs Users's Guide to walk you through the projects.

Every ACI we can test with our high voltage motor control kit ( TMDSHVMTRINSPIN ) can be ID'd with MotorWare 12 (setting up user.h correctly).  There are these low voltage ACI motors used for traction or high speed drills/pumps (like 1KHz) that are not ID'ing correctly.  We will fix those as well, but it looks like it is Sept/Oct relase best case with the other priorities.

Thanks.