Reducing Cogging Torque with Rotor Surface Notches in Double-Layered IPMSMs

In this study, a design method is proposed for forming notches on the rotor surface to reduce cogging torque of interior permanent magnet synchronous motors (IPMSMs) with double-layered magnets. The predominantly based theoretical equations and can be applied general IPMSMs, regardless arrangement. First, waveform square air-gap flux density (Bg2) reference model approximated using two-step trapezoidal waveform. Using approximation, harmonic components Bg2 are formulated when fabricated surface. Additionally, we derive that minimizes main torque. position width determined derived waveform, only notch depth adjusted by finite element analysis. analysis reveals optimized placement significantly reduced. Furthermore, prototypes were manufactured their waveforms measured. measurements confirm amplitude major