A Novel Two-Phase Permanent Magnet Synchronous Motor Modeling for Torque Ripple Minimization

Abstract

This paper proposes a novel two-phase, two-pole, permanent magnet synchronous motor (PMSM) with dual U-core stator structure for torque ripple minimization. The proposed motor is modeled based on the conventional single-phase U-core PMSM with approximate output power and core dimension. Torque ripple in the novel motor can be reduced significantly due to 90 electrical angle phase shift in two sets of magnet pairs and 90 shift in two-phase excitation currents. Characteristics of both PMSMs such as back-EMF, cogging torque and electromagnetic torque are analyzed and compared by using the 3-D finite element analysis (FEA). As shown in the result, the cogging torque and torque ripple in the novel two-phase PMSM are efficiently reduced with sinusoidal back-EMF waveform and reasonable current density value. The validity of both PMSM models is also verified by the comparison between simulated and experimental measured results.Index Terms-Cogging torque, dual ferrite pole pairs with 90 electrical angle shift, electromagnetic torque, FEA, torque ripple.

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