Xiuhe Wang

This work presents a sensorless control strategy for SynRMs based on dual-band hybrid biaxial high-frequency signal injection (Bi-HFSI) strategy, aiming to enhance torque performance. The proposed approach concurrently mitigates two dominant sources of torque ripple: inherent torque ripple caused by motor tooth-slot structure and high-frequency (HF) components induced by signal injection. To suppress these effects, a compensation signal is designed via nonlinear function fitting, and a hybrid HF voltage waveform is synthesized and injected using biaxial pseudo-random (Bi-PR) excitation. This configuration effectively reduces HF current noise while maintaining accurate rotor position estimation. The proposed strategy is validated through both finite element analysis and experimental testing, exhibiting significant torque ripple reduction under various load conditions, particularly under high-load operation. Although the integration of the compensation signal adds some complexity to the analysis of HF currents, it significantly enhances torque output quality and ensures reliable rotor position tracking. Power spectral density (PSD) and noise analysis confirms that the proposed method achieves lower noise levels than conventional square-wave injection, demonstrating its feasibility for high-performance sensorless SynRM drive applications.

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.