As implied in Chapter 1, the commercially named BDFRM may be considered a flux modulation reluctance machine that has two windings in the stator (both AC three-phase, for example, or one AC three-phase and one DC-fed) placed in semiclosed uniform slots and a salient pole rotor with P_r poles. The two stator AC-distributed windings, primary and secondary (controlled), have different numbers of pole pairs p_p , p_s and are called primary (power) secondary windings. It has also been demonstrated that the higher the magnetic saliency in the rotor, the better the magnetic coupling of the two windings and thus the higher the torque for given primary (power) and secondary (control) winding mmfs.