Good evening,
I'm using lab01b to verify my hardware is working properly, and found that the commanded SpeedRef_kRPM does not match the excitation frequency of the voltage waveform. Note that I've made the modification of adding an absolute encoder and replacing this electric angle with the angle generated by the angle_gen module, as it provides a more accurate measurement of the actual electric angle. The commutation is working, and it is much more efficient that using the angle from the angle_gen module, however, I'm seeing an unsual discrepancy between the commanded speed and the frequency of the excitation waveform. My commanded speed is 10 kRPM, which for a three pole pair motor, should equal 500 electrical cycles per second. The plot below, however, shows a period of ~163 samples @ 20kHz ISR = 8.15ms or ~122 Hz. Since the lab is based on open-loop control, do you have any suggestions as to why there's such a large discrepancy in the excitation frequency?
PWM freq: 60 kHz
ISR freq: 20 kHz
SpeedRef_kRPM: 10 kRPM
Number of pole pairs: 3 pairs
Thanks for your support!
Best regards,
Chris
