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TMS320F28027F: Zero-speed startup, hall-effect sensors, and torque control

Asif Ahmed
Expert 1570 points
Part Number: TMS320F28027F
Other Parts Discussed in Thread: MOTORWARE, DRV8301, DRV8305

Hello -

I am designing custom hardware for a traction motor application. I have a few questions/concerns around startup torque.

  • I know several different aspects of zero-speed startup have been discussed previously, but most of those posts are 2-3 years old, so I am just curious if there are any recent developments regarding zero-speed startup (with heavy load, a la traction motor)
  • I see that Motorware 17 has been released and it contains a lab for hall effect sensor startup using BLDC commutaion, with transition to FOC. Does this work for pure torque control as well (speed controller disabled)? I honestly would love to avoid the use of the sensors if at all possible.
  • Are there any examples/guidelines to using hall-effect sensors with the F28027F? IO is limited on this board after incorporating a DRV8301/DRV8305 w/ SPI, etc.

Any advice is much appreciated!

Best,

-asifjahmed

  • 0
    TI__Genius 17175 points
    Yes, lab11e can be modified to use only torque control instead of speed control. You can also explore lab21 for sensorless startup, but performance varies for that lab depending on your motor structure.

    For Hall sensor lines, you should be able to route the lines to three CAP inputs if you have availability on the pinout. Are you using a specific development kit (Control card, Booster pack)?

    Sean
  • 0 in reply to Sean Bigley
    Expert 1570 points
    I am developing a custom board using the F28027F. There is only one ECAP IO, correct? Can I use standard IO for hall sensors? I'm actually using the ECAP for another purpose.
  • 0 in reply to Asif Ahmed
    TI__Genius 17175 points
    You can use standard GPIO for hall sensors if you'd like, our older BLDC examples used GPIO for this purpose. You can edge-trigger them for interrupts if you'd like, or you can poll the IO pins to determine rise/fall events, the choice is yours.

    Sean
  • 0 in reply to Sean Bigley
    Expert 1570 points

    Thanks, Sean. What method does the example lab in Motorware 11 use? Can this use standard GPIO?

    Best,

    asifjahmed

  • 0 in reply to Asif Ahmed
    TI__Genius 17175 points
    Please take a look at the lab11e writeup in Motorware, it goes into detail regarding how the hall sensors are integrated, even for the F28027F. There is an example for the F28027F using the HVKit and the CAP lines. You can take a look at that code to get an understanding of how it works and change it to suit your needs.

    Sean