• State
  • Locked Locked
  • Replies 5 replies
  • Subscribers 82 subscribers
  • Views 713 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

TIDM-02012: Running custom motor sensorless with SDK 4.02 example

Simon Goodwin
Prodigy 10 points

Part Number: TIDM-02012
Other Parts Discussed in Thread: SYSCONFIG

Dear Forum,

I am trying to get the TIDM-02012 eCompressor example running with a custiom motor.

I have a multitude of problems:

With the example from SD 4.01 I manage to run my hardware up to level 3. That is the motor is turning properly under v/f and i/f control but the estimator is not displaying the right speed.
The guide states the estimated speed needs to be near to the reference speed, but does not give a hint what to do if not.

With the newer version of the example there are multiple issues around the external watchdog and the MCU disabling the gate driver.

Is there a guide on how to tune the FAST estimator?

With kind regards,

Simon 

  • 0
    TI__Guru 54445 points

    The software doesn't do more than just configure the pins going to the external watchdog as GPIOs, but it does look like the pin numbers we used for those signals changed between 4.01 and 4.02. I think if you remove the FSI configuration from the hal.sysconfig you should be able to set them back to their original locations if that's what appears to be causing the issue. I think some of these changes were for a new revision of the hardware that doesn't appear to be up on the design page--I'll check on that next week. Thanks for your patience.

    For more info on using FAST, you can see the InstaSPIN User's Guide.

    Whitney

  • 0 in reply to Whitney Dewey
    Prodigy 10 points

    Hi Whitney,

    thank you for your quick answer!

    After removing the FSI module the motor is running without periodic interruptions. So that helped, thanks!

    Regarding the wrong speed estimation I worked through the InstaSpin UserGuide but have problems locating the variables that it references.

    E.g. according to the UserGuide USER_IQ_FULL_SCALE_FREQ_Hz along USER_IQ_FULL_SCALE_VOLTAGE_V and USER_IQ_FULL_SCALE_CURRENT_A could theoretically cause an overrun in the esitmator. I have trouble to locate those. The setters for the estimator seem not to be used. so I am a bit confused to why the things in the UserGuide do not seem to align with the example software.

    During a level 4 motor identification the speed estimator seems to be ok. After the identification I see Rs to be estimated at exactly my multimeter measurment and L to be at 9.99997e-7 where I measured. I am a bit worried that the estimated inductance seems to be the same every time I run the identification.

    But neither value for inductance gives me a proper speed estimator in level 2 or 3, and only the force angle in level 4.

    I hope you can give me a clue. The user guide did suggest to test with different currents but I tride with no success.

  • 0 in reply to Simon Goodwin
    TI__Guru 54445 points

    To clarify, the FAST output is only used in level 4 (see the software block diagrams for the labs in the TIDM-02012 design guide), so the InstaSPIN User's Guide may not be quite as applicable to levels 2 and 3. Also, I think a lot of the reference code used InstaSPIN User's Guide was focused on the original InstaSPIN lab projects which are a bit different at the application level although they use the same core libraries.

    So build level 4 is running fine after the identification routine completes?

    Whitney

  • 0 in reply to Whitney Dewey
    Prodigy 10 points

    Dear Whitney,

    thank you for your help.

    I managed to get the motor to run. It is very picky on the combination of current and frequency used during estimation. Once I had a set of parameters all levels worked. To crosscheck I used an industry standard motor that was much easier to identify.

    During my work with this PCB I noticed some probems, e.g. ground reference of the shunts. Therefore I am pretty interrested in the update of the schematics you mentioned so that I can build my next version pincompatible to TIs designs.

    Thank you  very much"

  • 0 in reply to Simon Goodwin
    TI__Guru 54445 points

    Sure, I'm checking with the hardware owner to try to get an estimate of when we'll have the hardware updates posted. I'll get back to you when I know more.

    Whitney