8.5. Switched Reluctance Motor Control

Because of its intrinsic simplicity and inexpensiveness, the Switched Reluctance (SR) motor has become the subject of great interest in the field of electric motor drives. The motor is well suited to many applications, mainly due to its inherent fault-tolerant feature, operating at very high speed (which is limited by the type of bearings used), and its high reliability and robustness.

A four-phase 8/6 (8 stator and 6 rotor poles) SR motor is illustrated in Fig. 8-25. The SR motor is fundamentally simple in its construction. The stator and rotor resemble that of a variable reluctance stepper motor. Both the stator and the rotor have salient poles, and the number of rotor and stator poles is always unequal. Although many combinations of the number of stator and rotor poles are possible, 8/6 four-phase and 6/4 three-phase types have found widespread use.