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motor not identified by FAST

Steve Huang
Prodigy 50 points

Other Parts Discussed in Thread: DRV8312

Hi,

I have a motor with the following parameters:

L=0.39H;   Rs=67ohm;   kv=2.4 V/Hz



Using proj_lab03a:

The FAST Identifier returns Rs= 4753ohms.

What other parametes should I modify to get an accurate Rs?

It didn't run on the DRV8312-69M-Kit, too.

Thanks.

  • 0
    TI__Guru** 119680 points

    Steve Huang said:
    The FAST Identifier returns Rs= 4753ohms

    That is what happens when the U or V phase isn't connected to the inverter. It's measuring air resistance.

    Steve Huang said:
    L=0.39H;   Rs=67ohm;   kv=2.4 V/Hz

    The specs of this motor imply it is likely high voltage, so the DRV8312 is inappropriate. With 2.4 V/Hz, your Bemf would be greater than the bus voltage at 10 Hz.

    Steve Huang said:
    Using proj_lab03a:

    Why are you using 3a?  Did you start with lab02?  Regardless, you first need appropriate HW.

     

     

  • 0 in reply to ChrisClearman
    Prodigy 50 points

    Thanks Chris.

    You are right. It is  a high voltage motor. I am trying to run it at 50V regulated current. Is it possible to just run lab02 and measure the resistanse under 50V?

    I just tried lab02b and it return Rs=2.21869e+38...

    Using a Fluke multimeter, I measured the resistanse of the motor winding at the connector and it is 66ohm. 

  • 0 in reply to Steve Huang
    TI__Guru** 119680 points

    It should be able to do 50V

    You will want to change the user.h

    USER_IQ_FULL_SCALE_VOLTAGE_V (50.0)

    Make sure the toggle switches are in the midle. It looks like one is turned off which is holding a leg in reset. That's why the values are so large.