Part Number:TMS320F28069M
Good afternoon,
I'm revisiting an existing board design to further improve the current efficiency. I was able to work my way through all the labs, including lab12 with instaSPIN, and reach the max speed of the motor, ~24 kRPM. However, it runs at roughly twice the expected current, so I know that it is not running efficiently.
I revisited lab01c and found that the current tracking performance is terrible. With a constant Iq_Ref of ~0.1, the measured Iq signal looks like noise. There is a slight bias towards the reference Iq, but way too much oscillation. Interestingly, the motor does spin, but it looks nothing like the expected output from the lab tutorials. After seeing this, I took a step back to lab01b and found that the current waveforms are not very well formed. Perhaps I am not sampling the current channels at the correct location?
Here's a snapshot of the three voltage and two different examples of current waveforms, at different speeds, from the datalogger. As you can see the waveform looks nothing like the clean sinusoidal signal in the example. I did have to modify hal.c and hal.h in order to add 4 additional ADC inputs (2 analog inputs for an encoder, and 2 analog inputs for user input). Could there be a problem created by adding these additional inputs?
Voltages
First and second example (different speeds) of phase A, B, and C currents during open-loop control (lab01b)
Could there be an issue with my DRV8303 configuration?
If you believe there may be a hardware problem, please provide your suggestions for troubleshooting the issue.
Thank you for your support!
Best regards,
Chris