Commutation Frequency

NI-Motion

Commutation Frequency

The controller updates the command voltage and the commutation phase every update period. To commutate brushless motors smoothly, the controller must update the phase at least six times per electrical cycle. Therefore, the commutation frequency is limited by the update rate of the control loop. To calculate the maximum commutation frequency supported at a particular PID update rate, use the following formula:

commutation frequency =