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Problems to achieve max RPM - INSTASPIN LAUNCHPAD + BOOSTERPACK 8301

Flavio Alves
Prodigy 225 points

Other Parts Discussed in Thread: DRV8301

Hello,

I'm using InstaSpin Launchpad F28027F and DRV8301 Boosterpack to drive a BLDC motor.

The motor must operate at 10.000 rpm max speed at 24V. I could do this using other controller solution. But I intend to use Launchpad+BoosterPack.

I'm using Lab03b as the reference project. When I change to have 10.000 rpm speed, the controller can do just 8.330 rpm max speed.

If I change the controller voltage to 30V, I can have the desider 10.000 rpm. But, unfortunately, I can't do this at the final design.

Why is this happening? I am just new at motor control, and I would like to ask help in make it working.

What is the initial information I need to provide in order to make it easier to solve this issue.

Thank you in advance.

Best regards,

Flavio

  • 0
    TI__Guru** 119680 points
    the modulation of the bus voltage is limited to a pure sine wave in all projects except proj_lab10
    in proj_lab10 you can increase the overmodulation from a value of 1.0 up to 1.33, which will give you about 25% more speed typically.

    the other controller solution you have is obviously doing BLDC trapezoidal modulation which allows more bus voltage, hence more power to the motor.

    FOC is typically done with sinusoidal modulation or space vector modulation (value of 1.15 maximum). In our solution we also allow the modulation to move into full BLDC. To do this you need the algorithms we provide that sample the currents at the best time and select which of the samples to use for best results.

    Part 5 of the LP + BP Video series covers this topic and others:
    www.ti.com/.../support_community.shtml
  • 0 in reply to ChrisClearman
    Prodigy 225 points
    Hello Chris,

    I changed here the project to proj_lab10 and set OverModulation variable to 1.23 in order to achieve my desired speed (10.000 rpm).

    Thank you very much.

    Flavio