Torque ripple comparison of short-pitched and fully-pitched winding switched reluctance machine

Compared with the conventional short-pitched winding switched reluctance machine, the fully-pitched winding machine produces the effective electromagnetic torque by utilizing the changing mutual inductances among the phase windings. Previous works show that the fully-pitched winding machine can offer better circuit utilization, higher ratio of torque and current and higher efficiency. This paper compares the static and dynamic performances of these two winding configuration machines at the condition of same outline size, phase voltage and revolving speed. The results show that the advantages of fully-pitched winding machine only appear in the low speed range. According to low speed applications, such as servo drives and torque machine, the torque ripple reduction is necessary. This paper introduces the instantaneous torque closed-loop control to suppress the torque ripple of two machines. By experimental comparison, it is seen that the fully-pitched winding machine is superior to short-pitched winding machine only regarding to low speed applications.