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In recent years, Flux Switching Permanent Magnet (FSPM) machines have attracted notable attention in direct drive, low speed, and high torque density applications such as wind turbines. However, their relatively high cogging torque has been identified as a significant challenge for such applications primarily because of its effects on both starting and running performance of the wind turbines. The authors, therefore, aim to present a modified approach that can improve the cogging torque issue and eliminate the weaknesses of the previously introduced designs. To reach this goal, first, an operating point is chosen for the studied machine regarding the available small‐scale turbines in the market. Then, the potential benefits of combining different cogging torque reduction schemes are investigated thorough the proposed method. This is intended to be done on the rotor teeth without imposing any complications or extra costs. The results show that a simultaneous improvement in the cogging torque and the energy conversion capability of the machine could be achieved through this cost‐effective approach. To end with, the sensitivity of the best cases to the expected manufacturing tolerances is investigated. All analyses are performed via two‐dimensional finite‐element (2D‐FE) models, the accuracy of which has been pre‐certified through experimental measurement. [ABSTRACT FROM AUTHOR]

In this work, a permanent magnet synchronous motor is designed for an electric city bus. The unit winding factor is considered for torque capability enhancement and completely open slots are adopted for low‐cost rectangular wire winding implementation. Accordingly, extremely large pulsating torques that are predictable should be mitigated through the rotor design possibilities. In this regard, a modified Halbach pole configuration, named axially segmented Halbach, that is capable of producing considerably smooth torque as well as retaining the large mean torque is proposed. First, an optimised conventional Halbach array is calculated as the initial design. Then, following a detailed introduction to the new design concept, the modified Halbach pole parameters are obtained through the proposed 2D model‐based optimisation algorithm. A rotor step skewing scheme is also evaluated to make the final comparisons, which are carried out via 3D FE models. The results demonstrate the admirable performance of the proposed Halbach configuration as an effective solution for torque profile improvement. [ABSTRACT FROM AUTHOR]

A modified configuration for Permanent Magnet Assisted Synchronous Reluctance Motors (PMaSyRM) is studied in this paper. Conventionally, the PM materials are inserted in the flux barriers region of the rotor. Consequently, the PMs sizing parameters will be restricted to the available space that may limit the efficient use of PMs benefits. In this study, a portion of the rotor structure is replaced with an Interior PM (IPM) rotor so that an axially segmented integration of IPM and SyRM is obtained. Thus, the PMs design is performed specifically in the IPM segment independent of the SyRM scheme, while the SyRM segment remains PM-less. The main motivation of this concept is to improve the contribution of the PM material in the total torque as well as utilizing the special property of the proposed rotor configuration for pulsating torque reduction. A computationally cost-effective algorithm is proposed for the optimal design of IPM-SyRM motor by which a low-power design is carried out for a lightweight electric vehicle. The results for torque profile characteristics, PM volume, power-factor, and efficiency are compared with a conventional PMaSyRM that has been optimally designed as the reference case. Finally, a prototype is constructed to verify the theoretical analysis. [ABSTRACT FROM AUTHOR]