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This paper proposes a new modular hybrid excited flux switching motor (MHEFSM) with flux gaps, adding the fault-tolerant capability to the proposed motor. The proposed motor uses an E-Shaped stator, as the middle teeth of E-core produce fault-tolerant capability, and in C-core, this capability is eradicated. The no-load flux linkage is calculated by the magnetic network model (MNM) to reduce time and disk storage. The drawback of the constant flux linkage of PM motors is overcome by employing field excitation (FE). The FE helps in regulation flux at higher speeds. The motor leading geometry variables are optimized by using Genetic Global Optimization (GGO). The GGO helped in refining the structure of the motor and has improved the flux linkage by 68.18%, average torque and torque density by 62.35% each, reduced torque ripples by 20.62%, and cogging torque by 18.52%. The volume of permanent magnet (PM) in the proposed MHEFSM is reduced by 36.24%, and 48.49% higher average torque and torque density is obtained compared to the state of art motor proposed in the literature. Furthermore, a 3D analysis of the proposed MHEFSM is done to further evaluate the electromagnetic performance.INDEX TERMS Finite element analysis, flux gaps, modular stator, variable flux machine, genetic optimization.

Slotting effect in electric machines reduces flux per pole that effect magnetic flux density distribution in the air gap which induces harmonics in magnetic flux density causing flux pulsation, that in turn generates dominant torque pulsation in the form of cogging torque and torque ripples. To overcome the abovesaid demerits, a novel outer rotor field-excited flux-switching machine (OR-FSFSM) with a combined semi-closed and open slots stator is proposed in this study. The developed OR-FEFSM offers a high-power factor, due to the utilization of the semi-closed slot for armature coils. The open slot stator structure was chosen for the field excitation coil, which effectively suppresses leakage reluctance that causes flux pulsation. Thus, the influence of torque ripples is reduced, and the average torque is improved. In order to investigate the effectiveness of the proposed OR-FEFSM, a detailed study of stator slot and rotor pole combinations are performed. Based on simplified mathematical formulation, 12S/7P (stator slot/rotor poles), 12S/11P, 12S/13P, and 12S/17P are the most feasible combinations. Finite Element Analysis (FEA) based on comprehensive electromagnetic performance is performed on each combination, and found that 12S/13P offers the highest average torque of 4.62 Nm, whereas 3.72 Nm, 2.72 Nm, and 1.68 Nm average torque is offered by 12S/17P, 12S/7P, and 12S/11P, respectively. Based on the initial analysis, 12S/13P was considered for further analysis and optimized using JMAG built-in Genetic Algorithm (GA). Moreover, thermal analysis was performed, and the proposed design was compared with the conventional design.

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