If phase-a poles of a stator are energized by a set of series-connected
coils with current ia, the rotor poles align with the stator poles of phase a.
We notice that the phase-b stator is the same as the phase-a stator except
that its poles are displaced by 15 in the clockwise direction. Similarly, the
phase-c stator is displaced from the phase-b stator by 15 in the clockwise
direction