• State
  • Locked Locked
  • Replies 3 replies
  • Subscribers 84 subscribers
  • Views 479 views
  • Users 0 members are here
Support feedback
Options
Options
Related

This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.

BOOSTXL-DRV8301: Do my motor values makes sense, I'm only getting about half the current I think I should be getting

Kustaa Nyholm
Expert 2005 points
Part Number: BOOSTXL-DRV8301
Other Parts Discussed in Thread: MOTORWARE

I'm working with InstaSPIN-FOC Motorware lab projects.

I've got the lab2b to work and it gives me the following motor paramters:

#define USER_MOTOR_Rr                   (0.0)

#define USER_MOTOR_Rs                   (0.066)

#define USER_MOTOR_Ls_d                 (0.00011)

#define USER_MOTOR_Ls_q                 (0.00011)

#define USER_MOTOR_RATED_FLUX           (0.065)

#define USER_MOTOR_MAGNETIZING_CURRENT  (NULL)

#define USER_MOTOR_RES_EST_CURRENT      (2.0)

#define USER_MOTOR_IND_EST_CURRENT      (-2.0)

#define USER_MOTOR_MAX_CURRENT          (5.0)

The motor appears to run quite nicely but I'm concerned 

about the values because the motor manufacturer lists the motor as:

Motor model 57HB94

Line to line resistance 0.135 Ohm

Line to line indutance 0.2 mH

Max peak current 40 Amps

Number of poles 6

Rated speed 3500

Rated voltage 24 V

So are my identified numbers in the correct ballpark or is there something wrong?

I'm not able to set the USER_MOTOR_MAX_CURRENT to 10 (or 9) Amps, the software

gives me an error. It was my understanding that with this kit I should be able to aim for 10 Apms?

I'm going to the get the higher current boostxl ASAP as my aim is 13 Amp (continuous, 40 Amp max).

When trying  lab04  the motor runs nicely and obeys the  IqRef_A but even when I load the motor

to the point of stall (or just above) my power supply indicates only 2.5 Amps telling me that

something is not correct?

Ok, need to start the weekend, I suppose I can figure this out myself but I'm always of the

opinion that it does not hurt to ask while you keep working at it...

cheers, have a nice weekend, Kusti

  • 0
    TI__Guru** 114905 points

    Hi Kusti,

    Your post is being moved to the C2000 forum for better support regarding INSTASPIN.

    When the motor stalled, have you examined the current in the motor phases?
    Have you looked at the phase voltages to determine if the outputs are being enabled or disabled?

  • 0 in reply to Rick Duncan
    Expert 2005 points

    No I did not examine the phase currents, only the current drawn from the lab PSU I'm using.

    I  braked the motor using my hand so was not able to do very "scientific" job of it but just

    before stalling the torque was very strong and it was drawing 2.5 Amps so I think it basically

    worked as expected but that something in the software is limiting the current.

    Also did not look at the voltages but at stall the current dropped but not to zero and

    when I let go of the axel the motor immediately spun up.

    I'll do a better job of this on Monday.

    cheers Kusti

  • 0 in reply to Kustaa Nyholm
    TI__Guru** 116090 points
    1. The identified motor parameters is correct, the Rs and Ls in motor specifications is line to line which is twice of identified motor parameters.
    2. What error reported? USER_MOTOR_MAX_CURRENT must be less than USER_IQ_FULL_SCALE_CURRENT_A.
    3. You need to set gMotorVars.IqRef_A to a high value to increase torque output, otherwise, the torque and power supply output current is fixed though the motor is stalled.