Harmonic Localization Analysis of Radial Electromagnetic Force in Interior Permanent Magnet Synchronous Motors Influenced by Saliency Effect

This study investigates the challenges posed by electromagnetic (EM) vibration noise in interior permanent magnet synchronous motors (IPMSMs), specifically focusing on the rotor saliency effect. Comprehensive harmonic localization models that incorporate the saliency effect have been developed to analyze magnetic flux density and radial EM force density (REMFD) in IPMSMs. An 8-pole, 12-slot spoke-type IPMSM serves as the primary model, exploring both temporal and spatial harmonic characteristics influenced by the saliency effect under no-load and load conditions through finite element quantitative analysis while tracing their origins to the magnetic field. A novel rapid layered traced optimization strategy for multiple objectives of further reducing REMFD under both no-load and load conditions while maintaining torque performance is proposed on the key rotor dimensions, based on the traceability of REMFD harmonics. Validation is conducted using multi-physics vibration noise prediction models and experimental measurements. The results indicate that reducing the saliency effect mitigates the harmonics of the main pole magnetic field under load, effectively reducing low-order REMFD and EM noise across various loading conditions. This study not only enhances the theoretical understanding of EM noise and vibration in IPMSMs but also offers a more straightforward optimization strategy for IPMSM design.