I have a BLDC motor setup where I control the inverter using hall-effect sensors. I now want to control the inverter using BEMF -signals. I can do the zero-crossing detection. In BLDC control the commutation point is 30° electrical after the zero crossing point. How can I create the commutation signal at the right time?
I was thinking about calculating the speed of BLDC using the zerocrossing detection, then the time of a period is known, the time of 30° electrical can be calculated and then using a death-time the commutation point can be determined.
Im using a compactRIO with FPGA the BEMF signals are measured with the NI 9223. this is an analog input. I have no idea how to calculate the speed of the motor with an analog input. I now how to calculate it using a single-cycled timed loop on the FPGA, but this can only be used with digital I/O.
