TMS320F28035: Motor running with noise and less RPM

Mohit kumar1

Part Number: TMS320F28035
Other Parts Discussed in Thread: CONTROLSUITE

Hi,

I am using the control suite example "C:\ti\controlSUITE\development_kits\DRV830x-HC-C2-KIT_v105\GUI_project_InstaSPIN_BLDC" as a base code on kit DRV830x-HC-C2-KIT_v105 .

My Motor is "U13 T Motor" and having full rpm is 4500@48V (tested with another ESC). I am able to run motor at maximum 3600rpm @48V after adjusting the flux threshold but it run too much noisy. Using voltage control mode only.(not able to run in cascade,velocity and current as not much know how of PID parameters adjustments as they takes time so tried basic with increasing the duty to increase the speed).

Motor parameter are adjusted in the code correctly as its 24 pole motor. Please let me know what im doing wrong?

I also tried another motor which has a higher pole and rpm speed upto 8000rpm@48V but that motor also runs at max speed aprrox 3600rpm @48V after aadjusting the flux threshold.

Thanks.

over 7 years ago

0 Sean Bigley over 7 years ago

TI__Genius 17175 points

Do you have any scope captures of the voltage waveform? Or the captures of the datalog waveforms from the GUI?

Sean

0 Mohit kumar1 over 7 years ago in reply to Sean Bigley

Intellectual 260 points

I have scope captured the waveform at 100% duty. Please check.

0 Sean Bigley over 7 years ago in reply to Mohit kumar1

TI__Genius 17175 points

What PWM frequency are you using? Your motor has a very high electric frequency at max RPM, so you will need a very high PWM frequency to ensure enough information is being sampled by ADC during the zero-crossing point

Sean

0 Mohit kumar1 over 7 years ago in reply to Sean Bigley

Intellectual 260 points

Hi Sean,

PWM frequency is 20Khz.
Shall I change to 40Khz or more?

Thanks,
Mohit

0 Sean Bigley over 7 years ago in reply to Mohit kumar1

TI__Genius 17175 points

I would recommend that you increase the PWM frequency, yes

Sean

0 Mohit kumar1 over 7 years ago in reply to Sean Bigley

Intellectual 260 points

Dear Sean,

I tried changing the PWM frequency from 20Khz to 40Khz but it did not help(same results). Then i try further changing it to 60Khz when i run the code motor stuck on startup and supply reached to max current limit.
My adc isr frequency is 20Khz. when i change both adc isr and pwm frequency to 40 Khz motor does not run.

Shall i share my instaspin bldc gui code with you if you can dig and find a solution?

Thanks,

Mohit

0 Sean Bigley over 7 years ago in reply to Mohit kumar1

TI__Genius 17175 points

Where did you edit the PWM frequency? You'll notice in the code that the assignment happens here:

// Define the ISR frequency (kHz)
ISR_FREQUENCY=20;
PWM_FREQUENCY=ISR_FREQUENCY;
T = 0.001/ISR_FREQUENCY; // Samping period (sec), see parameter.h

This section of code is in BLDC_Int_GUI_DRV83xx.c, not the settings header file. I would encourage you to validate the PWM frequency with an oscilloscope if you haven't already to make sure you are in fact running at a higher rate

We are not able to go over your code in depth, we do not have enough resources on our end to do this

Sean

0 Mohit kumar1 over 7 years ago in reply to Sean Bigley

Intellectual 260 points

Yes i did change the same.. Is there any thing else i should try?

0 Sean Bigley over 7 years ago in reply to Mohit kumar1

TI__Genius 17175 points

Were you able to externally verify that you're driving the output at the frequency you expect?

Sean

0 Mohit kumar1 over 7 years ago in reply to Sean Bigley

Intellectual 260 points

Yes, we are able to check the PWM output frequency on oscilloscope. I did not see any other option to change as the instaspin library source code is not available.

0 Sean Bigley over 7 years ago in reply to Mohit kumar1

TI__Genius 17175 points

InstaSPIN BLDC is completely open source. The GUI project itself does not have a full accounting of the source code as it was created by a 3rd party company that is no longer in business. InstaSPIN-FOC is the version that features a library without source code available

You should be able to achieve the same functionality with full source code if you use a project other than the GUI, such as this one: C:\ti\controlSUITE\development_kits\DRV830x-HC-C2-KIT_v105\InstaSPIN_BLDC

Sean

0 Mohit kumar1 over 7 years ago in reply to Sean Bigley

Intellectual 260 points

hi Sean, Thanks for your reply.
I have looked into that project too. I did not see much difference other than variable name and structuresname defined in InstaSPIN_BLDC. The implementation is pretty similar in both the projects. Bith uses the same InstaSpin BLDC library.
Thanks,
Mohit

0 Sean Bigley over 6 years ago in reply to Mohit kumar1

TI__Genius 17175 points

Mohit

If your company works with an TI field engineer, you can request access to the InstaSPIN BLDC source code for the library. It can be made available as a download. Having the source code may help you debug your issues more easily

Sean

0 Sean Bigley over 6 years ago in reply to Sean Bigley

TI__Genius 17175 points

Mohit

If there are no more questions here I will close this thread for now

Sean

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TMS320F28035: Motor running with noise and less RPM