I wrote the post with BLDC delta winding commutation sequence, and to this day a believe the findings are true.
But i have an issue that is occurring only in CCW rotation, at about 97% up to 100% duty cycle the motor starts to run rough but at a slight higher RPM (2600 to 3000) in short bursts (like it would have timing advance for short periods).
This is not happening on CW rotation, the RPM is the same in CW vs CCW up to 97% duty cycle, but above that in CCW there is the simptome described.
The strange thing is that this is NOT related to load nor to supply voltage (it is doing the same at 10, 20 even at 100 Amps and at 24, 37, 74 Volts supply), the only relation to the simptome i found is the duty cycle (above 97%).
Note the motor is run in sensor mode with no timing advance (not in SW not in HW), there is no cross conduction, all the drive signals on the gates check out fine the only thing that is a bit strange is that the phase wave forms look different (some pulses in the wrong places) in CW vs CCW, and i can not figure out why. I added a few scope images, they are measured with ground on U phase and channel A and B on V and W phase of the motor.
The question is, what causes the described simptom?
Photo nr 1 CW rotation duty cycle 100% NO simptome.
Photo nr 2 CCW rotation duty cycle 100% WITH simptome.
Photo nr 3 CW rotation duty cycle about 95% NO simptome.
Photo nr 4 CCW rotation duty cycle about 85% NO simptome.
Photo nr 5 CCW rotation duty cycle about 97% WITH simptome.