Analytical Radial-Force Sum Flattening of Switched Reluctance Motors Considering Current RMS

This paper proposes a novel derivation for radial-force sum flattening in a switched reluctance motor. The main objective of the proposed method is the reduction of the acoustic noise by flattening the radial-force sum, while having the lowest current rms. The proposed method is applicable to any switched reluctance motor as long as the zeroth-mode vibration is dominant, such as the case in which the stator pole-number is sufficiently high with a large stator outer diameter. Since the proposed method is analytical, no computational burden is imposed from applying the method. The proposed method was validated by electromagnetic finite element analysis, followed by mechanical and acoustic finite element analyses that show significant reduction in the acceleration and sound pressure level compared to the conventional square current excitation.