BRUSHLESS DC MOTOR
The rotor flux density distribution produced by the permanent magnets is represented by the green space vector
A power-processing unit supplies three-phase currents to the stator windings in such a manner that the resultant stator current space vector Is is 90o ahead of the rotor flux vector. The mmf distribution produced by the stator currents flowing in the stationary three-phase windings is equivalent to that produced by Is flowing in a single sinusoidally-distributed rotating winding whose magnetic axis lines up with Is as illustrated in this animation. Br.