Effects of Current Excitation on Nodal Forces in Switched Reluctance Motors

While switched reluctance motors (SRM) are suitable candidates for traction and automotive applications, they are subject to high torque ripple and acoustic noise which is caused by electromagnetic radial forces. In this paper, the production of nodal forces responsible for torque and acoustic noise creation in SRM is analyzed. Then, to minimize torque ripple, a torque sharing function which shapes the phase current is introduced. The effects of these current profiles on the radial forces has been compared to those using conventional current waveforms in SRM. It is shown that using this torque sharing function, torque ripple can be minimized while mitigating the production of radial forces by advancing the phase excitation period.