Other Parts Discussed in Thread: DRV8320, DRV8305, MOTORWARE, LAUNCHXL-F280049C
Tool/software: Code Composer Studio
Hi,
I've been stuck for two weeks now trying to get our fan motor to run at high speed (1400 Hz) but it always trips over current around 400 Hz .. 500 Hz.
I've tried too different types of motors, several different motor units, several LAUNCHXL and BOOSTXL units, nothing makes a difference.
It is NOT nFAULT from DRV8320, I've maxed out the motorVars.dacValH and motorVars.dacValL values from 255-3841 to 1-4094.
The motor is not observably using excessive current, the motorControl instaspin foc variables indicate 5-6Amps at around 6-7 Volts which matches the measure input carrent of 24 V / 2 amps pretty much.
One more data point, the motor has trouble starting. I set the initial speed at 20 Hz and the motor seldom reaches that but hovers and hesitates at -15 ... +10 Hz.
So in my desperation I hooked up the Anaheim_BLY172S_24V and with the TI user.h parameters that too has problems starting!!
And the Anahaim does not reach 400 Hz, maxes out at around 320 Hz and does not run smoohtly, I can hear and feel vibrations which have no discernible pattern or frequency.
As I think we can rule out hardware fault this must be some sort of systematic software issue, that is my guess.
Or can this be that the DRV8320RS (as it is configured in hardware) is not suited to these small motors?
I run the motor ID for Anaheim_BLY172S_24V and it produced values that are very much in line with what I can find in the user.h file, my values as comments:
#define USER_MOTOR_Rs_Ohm (0.4) // 0.373
#define USER_MOTOR_Ls_d_H (0.0007190173) // 0.000625
#define USER_MOTOR_Ls_q_H (0.0007190173) // 0.000625
#define USER_MOTOR_RATED_FLUX_VpHz (0.0327013217) // 0.0359
I'm at loss how to proceed and this has became a showstopper for the hole project.
We have had great success with BOOSTXL-F28027 + DRV8305 + MotorWare/instaspin FOC with number of motors,
No luck so far with with LAUNCHXL-F280049C + DRV8320RS / MotorControl SDK 3.0 Instaspin FOC with any motor.