Direct Instantaneous Torque and Axial Force Control Method for Linear-Rotary Switched Reluctance Motor With Two Radial Windings

Dual-winding linear-rotary switched reluctance motors (LRSRMs) suffer from large torque ripple and severe coupling between the torque winding and the axial-force winding. To address these issues, this article proposes a direct instantaneous torque and direct axial force control (DITC&DAFC) method to suppress torque ripple and reduce the impact of the coupling between two sets of windings. The DITC&DAFC method divides inductance-rising zone and inductance-falling zone according to the inductance characteristics, and uses hysteresis control to directly control the motor's instantaneous torque in different intervals. Therefore, the generation of negative torque is reduced, which effectively suppresses torque ripples. Meanwhile, the method obviates the calculation of current and flux linkage, thereby alleviating the demands on the controller. In addition, the mechanical structure and operating mechanism of 6/4 pole LRSRM with two radial windings are described in detail. The feasibility of the proposed control method is verified through simulation and experimental results.