I have a sensorless BLDC drive application where I need to get near 100% duty cycle on the power PWM while spinning at about 1300Hz (21 pole pairs, 3700RPM). However it appears that the six-step library only samples the BEMF during the off time, thus precluding the use of 100% duty cycle on the PWM. Here are my questions.
1) How much off time is required to sense the BEMF? Or how close to 100% duty cycle can I get using this method?
2) Do you have another library I can use that does not have this duty cycle limitation?
3) I don't need FOC, but if it would work in my application I am open to it. Would your FOC library run at 1300Hz or faster with a low inductance motor?