Investigation of Electromagnetic Vibration of Low-Cost Single-Phase Permanent Magnet Reluctance Motors

Single-phase permanent magnet reluctance motors (PMRMs) have attracted much attention because they combine the advantages of the low cost and simple structure of reluctance motor (RM) with high power density characteristics of permanent magnet (PM) motors. However, the unique topology makes them vulnerable to significant vibrations and noises in actual operation, limiting the potential of PMRM in a wider range of application scenarios. This article first investigates the electromagnetic vibration characteristics of single-phase PMRM. A general analytical model of radial force considering the stator and rotor slots is established to reveal the general principle of radial force frequency distribution of single-phase PMRM. Finite element analysis (FEA) models of different rotor structures are established to verify the theoretical derivation. The results show that the harmonic amplitude of the radial force is closely related to the odd-even nature of the time-frequency orders. Finally, a prototype was fabricated and experimentally tested for vibration and acoustic noise at different speeds under no-load and load conditions. The segmented rotor structure demonstrates its potential in suppressing low-frequency vibrations.