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DRV8300DRGE-EVM: MSPM0G3507 + DRV8300DRGE-EVM

VG
Prodigy 110 points
Part Number: DRV8300DRGE-EVM
Other Parts Discussed in Thread: MSPM0G3507, , DRV8300, LAUNCHXL-F280049C

Hi,

We are having a strange problem with respect to MSPM0G3507 + DRV8300DRGE-EVM combination for hall sensor based motor control.
We have a 24V hall sensor motor which comfortably spins to 45000 rpm with the above combination and does not have any problem.

However if we replace the motor with another 36V hall sensor based motor, the motor rotates for lower pulsewidth with less speed, but the read current is erratic and motor buzzes and vibrates and consumes a lot of current and phase current reads erratically to 18A etc if we increase the pulsewidth aka its speed (the power supply is not capable of providing this current and so the phase current reading looks bogus).

The same 36V motor works beautifully with another MCU and driver setup. With this working setup the current consumption of of 36V motor is less than 1 ampere.
Is it possible that the commutation sequence of the second motor is the problem?

Kind regards

VG

  • 0
    TI__Mastermind 23566 points

    Hey VG,

    Are there any major differences between the sensored 24V motor and the sensored 36V motor? 

    Have you measured the hall and input signals with he second motor to ensure correct commutation is taking place? If hall signals and inputs match then could you capture waveforms of GHx to GND and SHx to GND toggling?

    VG said:
    The same 36V motor works beautifully with another MCU and driver setup

    What MCU and driver is used in this setup? are the halls wired the same between both setups?

    Best,

    Akshay

  • 0 in reply to Akshay Rajeev Menon
    Prodigy 110 points

    We have a custom designed infineon XMC1302 based design which uses single drivers per phase and T0220 MOSFET where the 36V motor works as it should . The same motor will work on 24V also.

    The primary difference between the 24V motor and 36V motor is that 36V motor is max 350W and the 24V motor is max 75W. 

    One interesting observation is that when we work with the Smaller motor, the current readings are very close to measured externally and even the motor spins comfortably to 45K rpm., Whereas for the 36V motor the current readings are bogus with same setup. Initially we thought there is something wrong with our code edits but later we found that the Ti GUI also behaves in same way ruling that possibility out.

    The MOSFETs getting extra warm when it comes to 36V motor also is an observation. 

    Is there a possibility that different motor will have different commutation requirements?

  • 0 in reply to VG
    TI__Mastermind 23566 points

    Hey VG,

    Have you measured the hall and input signals with he second motor to ensure correct commutation is taking place? If hall signals and inputs match then could you capture waveforms of GHx to GND and SHx to GND toggling along with phase current?

    Please also send us MOSFET and datasheets of the two motors.

    Best,

    Akshay

  • 0 in reply to Akshay Rajeev Menon
    Prodigy 110 points

    This is what the signals look like. It does not look what it should be!

  • 0 in reply to VG
    TI__Mastermind 23566 points

    Hey VG,

    Please send us the typical waveform to cross check and also the above requested material.

    Best,
    Akshay

  • 0 in reply to Akshay Rajeev Menon
    Prodigy 110 points

    In the above waveform, HALL A should look like B and C which is it is not. In our other board which works smooth we have HALL A,B,C waveforms are similar but in the above HALL A is seen as several short pulses which we are trying to decode and understand why it happens.
    One interesting observation is that F2800137+DRV8323RS ,MSPM0+DRV8323RS, MSPM0+DRV8300 kits behave the same way.

  • 0 in reply to VG
    TI__Mastermind 23566 points

    Hey VG, 

    Will review and provide an update next week.

    Best,
    Akshay

  • 0 in reply to Akshay Rajeev Menon
    TI__Mastermind 23566 points

    Hey VG,

    It seems like there is some issue with hall A commutation, as if it is being pulled low around the same frequency as your PWM signal.

    The DRV8300DRGE EVM works with  LAUNCHXL-F280049C, did this combination work with the 36V motor? is this the GUI you were referring to?

    Best,
    Akshay

  • 0 in reply to Akshay Rajeev Menon
    Prodigy 110 points

    We checked the DRV8300 with an STM32 development board and the hall signal looks correct.

    In this case with MSPM0G3507 launchpad and the F2800137 launchpad we are seeing the HALL A signal pulled low from the MCU most probably

  • 0 in reply to VG
    TI__Mastermind 23566 points

    Hey VG,

    what about LAUNCHXL-F280049C?

    Best,
    Akshay

  • 0 in reply to Akshay Rajeev Menon
    Prodigy 110 points

    Hi Akshay,

    We do not have a LauchXL-F280049C with us to test.

    kind regards

    VG

  • 0 in reply to VG
    TI__Mastermind 45236 points

    Hi VG,

    Sorry for the delay. Your post was moved to the C2000 forum.

    VG said:
    In this case with MSPM0G3507 launchpad and the F2800137 launchpad we are seeing the HALL A signal pulled low from the MCU most probably

    What F2800137 software solution are you currently using? Is it the Universal Motor Control Lab in the MCSDK?

    Best,

    Kevin