13.21 Motor Control

The commutation loop of a BLDC motor control is a Phase-Locked Loop (PLL), which locks to the rotor’s position. Note that this inner loop does not attempt to modify the position of the rotor, but modifies the commutation times to match whatever position the rotor has. An outer speed loop changes the rotor velocity, and the commutation loop locks to the rotor’s position to commutate the phases at the correct times.