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BOOSTXL-DRV8305EVM: The motor does not rotate regularly when the SVPWM signal is rotating.

Mathias Mettauer
Prodigy 40 points
Part Number: BOOSTXL-DRV8305EVM
Other Parts Discussed in Thread: BOOSTXL-DRV8301, , DRV8301, DRV8305, CONTROLSUITE, MOTORWARE

I switched from BOOSTXL-DRV8301 to BOOSTXL-DRV8305EVM because I need a little more power.
Everything worked fine on the 8301, except for the detail with too few power resources. On the DRV8305EVM I have the problem that the motor is not rotating properly. When I read the signals, it doesn't look very good either.

I am used to such signals from the DRV8301 board:

drv8301

Now with the DRV8305 it looks like this (same svpwm  signals):

drv8305

I am using the 3-PWM-Signal Configuration. I also tried various configurations in the SPI register. Without success. What may be the problem? I noticed that the motor currents are partly identical, which I do not understand.

  • 0
    TI__Guru** 115420 points
    What drive control algorithm are you using? Sensored-FOC? Sensorless-FOC? Or v/f scalar open loop control? Are the motor running with current close loop?
    Did you change the scale setting per BOOST-XL DRV8305 which has different current and voltage scale with BOOSTXL_DRV8301? And could you please check if the pwm mode is correct in DRV8305?

    You might download and install controlSUITE or motorWare as the links below, both have some example projects for motor control on boostxl-drv8305 with C2000 controller.
    www.ti.com/.../controlsuite
    www.ti.com/.../motorware
  • 0 in reply to Yanming Luo
    Prodigy 40 points

    I am generating a 3Phase rotating SVPWM Signal from the micro-controller (not from TI). In the pictures you see the generated svpwm-angle. The motor angle is measured from an encoder. I tested the signals on other driver chips, where the result was fine (like in the picture).

    No FOC-Regulation loop is implemented in the measurement-pictures. I used this to test the driver, to see if it works. With other drivers the motor is rotating with the svpwm angle very smooth (no load on the motor). If this works, i will activate a Sensored FOC Control-Loop.

    I changed the current and voltage scaling corresponding to the different resistors on the boards. But even if the scaling is wrong, the signals have to look different.

    For example, the current of two phases in a given time looks the same:

    drv8503_zoom

    Why could this happen?

  • 0 in reply to Mathias Mettauer
    Prodigy 40 points

    To get closer the problem, I tried to change any parameters to see if it would help. At a PWM frequency of 1kHz, the motor finally rotates cleanly. Only now it's very loud. I'll try enlarging the shunt. I can imagine that there may be some resonances. If anyone has an idea of what else you can do, I'm open to it.

  • 0 in reply to Mathias Mettauer
    Prodigy 40 points
    Changing the shunt did not help. The only thing i can do now is to look for another driver. I don't know where to search for the problem.
  • 0 in reply to Mathias Mettauer
    TI__Guru** 115420 points
    You may try using C2000 controllers, like LaunchPad-F28027F, LaunchPad-F28069 which can connect BOOSTXL-DRV8305EVM, there are many sensor or sensorless FOC example projects, that use SVPWM for motor control in controlSUITE and motorWare. Please let me know if you meet any questions on both utilities s/w, you might spin motor in just minutes if you use instaSPIN-FOC in motorWare.

    www.ti.com/.../controlsuite
    www.ti.com/.../motorware