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LAUNCHXL-F280049C: instaSPIN FOC Stop motor method

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Prodigy 120 points

Part Number: LAUNCHXL-F280049C

Hi, 

I use is07 example to contorl BLDC. When I set speedRefHz = 0  to stop my motor, the motor takes a while to stop. 

If I use flagRunIdentAndOnLine = 0 and until speedHz =0, the method is fast. But the motor will spin by inertia.

Is there any way when I speed control and motor to limit Torque to stop immediately or the position should not be too far apart method?

thanks 

Jerry

  • 0
    TI__Guru** 117270 points

    That's a normal state for free stop the motor, you have to implement the braking mode if you want to immediately stop the motor. In most cases, two braking modes below are implemented. 

    1. Regenerative braking happens when the speed command is reduced from a higher value and in that case, the energy will back flow to raise the dc bus voltage of the link capacitor. A separate regen braking controller may not be needed, the same control loop that was controlling the motor is good enough. A separate Dc voltage monitor and dissipation of excess energy in a resistor may be one way to dissipate the energy.

    2. If you don't want regen at all, then some engineers try to turn on all three bottom switches, in which case the energy is dissipated as heat within the motor heating it up. If regen is sporadic, then one can consider this approach.

    You try to look though some engineering text books that should have details about the braking mode.