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BOOSTXL-DRV8301: DRV8301 +F28027F as a high speed controller (12000 rpm) ?

Part Number: BOOSTXL-DRV8301
Other Parts Discussed in Thread: LAUNCHXL-F28027F, , TIDA-00735, TIDA-00643, MOTORWARE

Hello,
I am trying to develop an esc for bldc sensorless motors with speeds between 8000 and 12000 rpm
I have selected for this application the LAUNCHXL-F28027F and BOOSTXL-DRV8301 as evaluation boards


1) Is my choice suitable or are other boards more suitable?
2) Is it possible to use the INSTASPIN FOC algorithm with such speeds?

Thank you for your help

  • Hi Anthony,

    The LAUNCHXL-F28027F + BOOSTXL-DRV8301 is a valid system solution to use InstaSPIN-FOC. RPM will depend on the number of pole pairs in the motor, because RPM = (60 * fe) / (# pole pairs), where fe is the electrical frequency of the motor. The InstaSPIN-FOC yields a speed reference variable in the firmware/GUI ("speedRef"), so you can calculate the number of pole pairs in your motor can attain the RPM needed with InstaSPIN-FOC given an electrical frequency of 100 - 300 Hz. 

    Usually to attain higher RPMs, it is recommended to use trapezoidal over FOC because it is easier to measure or calculate BEMF windows with trapezoidal rather than sinusoidal commutation. You can use any MSP + DRV solution for this, depending on the motor voltage and current required for the application. 

    Thanks,
    Aaron

  • Hi Araon,

    Thank you for your feedback, Indeed, I did not specify the type of engine, it is a 24 poles engine.

    I am currently evaluating these two types of switching to define which is more stable. The documents TIDA-00735 and TIDA-00643 in addition to the TIDUAK1 "TI Designs High-Speed Sensorless-FOC Reference Design for Drone ESCs" which shows the possibility of using the FOC with INSTASPIN, however it was tested up to 1.kHz.

    1) Is the FOC algorithm limited by the Current loop bandwidth ?
    2) If yes, the limit is indicated at 2.5 kHz (hardware dependent), will the following µCs be able to work at this frequency?  
        a) F28027F
        b) F28069M

    Thanks,

    Anthony

  • Hi Anthony,

    I am forwarding to C2000 team for more support on InstaSPIN-FOC using MotorWare. 

    Thanks,
    Aaron

  • 1) Is the FOC algorithm limited by the Current loop bandwidth ?

    The required current loop bandwidth depends on CPU clock frequency, motor and the expectation control performance. A higher speed motor will need a higher control frequency (current control loop bandwidth). The F28027F with 60MHz may support 15k~20kHz control frequency if using InstaSPIN-FOC, that should be fine for an ESC motor as you mentioned above.

    F28069M controller is 90MHz clock frequency CPU, so that could support much higher control frequency and speed motor than F28027F.

  • Hi Yanming,

    Thank you for your feedback. This confirms what I had understood.

    The InstaSPIN-FOC is able to switch between FOC and trapezoidal automatically in case of too high speed or instability ?

    Anthony

  • I don't think it's easy to implement since the PWM mode is totally different, and the BEMF ZCP can't be checked for sensorless trapezoidal control when the motor is running with the InstaSPIN-FOC.