Inhibitory Effect of Radial Force to Switched Reluctance Motor with Stator Pole Slot

The radial force has a unique impact on vibration and noise to Switched Reluctance Motor (SRM) which limit its application. The rectangular slot on the top of stator can decrease the radial force where the original unidirectional radial flux density component is decomposed into radial and tangential ones. The air-gap magnetic field is divided 4 regions before and after slotting in this paper, where magnetic field line is simulated with the parabola type and straight line. The influence of the stator slot on radial force, torque ripple and average torque of SRM is analyzed by means of theoretical calculation and the Finite Element Method (FEM). It is proved that the slotted structure can effectively suppress radial force and that the degree of inhibition is affected by the slot width while the average torque slightly decreases with slot on the top of stator.