I have another question, In the sensorless method we have to read the back emf signals of U,V,W and apply the switching algorithm, but my doubt is the back emf is read from the U,V,W terminals which are generated by the motors, but we also apply our output waveforms (SVPWM etc) on the same terminals and the back emf cancels the applied voltage then how can we uniquely read the back emf waveforms? Please advise.
I did some study and found that only during Hi-Z term used by TI where one of the phases is OFF, we can find the BEMF zero crossing in trapezoidal control but in the FOC we can’t read the BEMF.
Yes, you are correct.
At the moment, SimpleFOC does not support reading BEMF.
In our most recent code changes in the dev branch on GitHub we have laid the foundation for doing it, by allowing individual control over the phases. But we still have not written BEMF sensing or motor driving code based on it.
These things will probably come to the library eventually…