## 1 Introduction
However, the negative effects of rotor eccentricity in high-pole fractional-slot PMSMs were found to be more than twice that in integer-slot PMSMs with a lower pole count, in terms of unbalanced electromagnetic forces. In [34], a 28-pole 2.2 kW AF-PMSM was evaluated by means of detailed 3D FE analysis, considering static inclined eccentricity. The study examined the effects on airgap flux, back-emf, axial forces, and uneven forces, concluding that static eccentricity deforms airgap magnetic fields and generates unbalanced magnetic force (UMF). This UMF leads to continuous torque acting on the bearings, resulting in additional mechanical load, vibration, and acoustic noise. These findings led to increased interest in modeling static inclined eccentricity, which was addressed in [35] through a magnetic field calculation approach that evaluates static inclined eccentricity in AF-PMSMs, though it is also applicable to RF-PMSMs. This method effectively estimates slight changes to the spatial flux density distribution caused by eccentricities. Related research on special modular PMSMs with TCW can be found in [36], which further evaluates the effect of both static and dynamic eccentricity on the performance of these machines. The study found that while mean torque and back-emf are not substantially impacted by eccentricity, cogging torque and radial forces are significantly affected, which is concordant with [34,35]. In turn, partial demagnetization is addressed in [37], where a 42-pole LSHT-PMSM was analyzed through the finite element method (FEM) under various degrees of demagnetization. The study observed differences in the harmonic content of the torque waveform, though the effect was minimal, highlighting the need for advanced diagnosis techniques for fault detection. From the above, it should be noted that high-pole-count WRSGs and LSHT PMSMs, particularly those with the AF topology, have been addressed in the literature. Nevertheless, to the best of the authors' knowledge, there is no research focusing on the impact of the usual faults on the performance of high-pole-count IMs or SynRMs, despite several design proposals for these machines being available in the literature [17, 18, 19], along with off-the-shelf 12-pole machines used in special applications. Furthermore, although it is widely accepted that these faults often go unnoticed during routine inspections, the literature has yet to quantify the extent to which topology-specific parameters influence fault sensitivity in LSHT machines, particularly in a comparative context. This paper aims to describe and demonstrate the impact of the usual faults in the performance of several LSHT machines using a numerical approach. Squirrel-cage IMs, SynRMs, and PMSMs are designed, optimized, and analyzed in this study with two objective speeds, based on detailed finite element simulations to isolate phenomena related to the faults. Also, the study covers several machine topologies and their specific faults, in order to underline the need for advanced diagnostic techniques oriented to each machine topology. The remainder of the paper is organized as follows. Section 2 describes the usual faults in conventional machines and provides a more detailed and focused literature review, including PMSMs, SCIMs, and SynRMs. Section 3 presents the methodology of machine design and analysis using FE simulations, also describing the theoretical background. Sections 4 and 5 provide the results of the assessment, considering the raw performance evaluation in faultless conditions in Section 4, and the impact of the usual faults in Section 5. Finally, Section 6 outlines the main findings and general remarks of this work.