Search

In this paper, an outer-rotor-permanent-magnet flux-switching (ORPM-FS) machine is proposed. It not only inherits the traditional flux-switching permanent-magnets (FSPM's) flux-switching principle and the high torque density, but also overcomes the FSPM's magnetic saturation and adds the slot area, thus producing favorable output torque capability at rated load and overload condition. By means of finite element method, the ORPM-FS machine is optimized through multi-level process for multi-objectives: the basic variables optimization for high output torque and low torque ripple, the pitch coefficient optimization for favorable torque characteristics and efficiency, the optimal selection for high efficiency at flux-weakening operation. At last, the electromagnetic performances of the optimized ORPM-FS machine are analyzed, which shows that the proposed machine can receive high torque density, low torque ripple, high efficiency, and favorable overload capability. [ABSTRACT FROM AUTHOR]

In order to reduce the axial length and increase the critical speed of the small magnetic suspension drive system, a new slice hybrid magnetic bearing (SHMB) with two radial air-gaps is proposed. The structure and suspension mechanism of the SHMB is introduced, and then the mathematical models of the radial suspension force are deduced using the equivalent magnetic circuit method. The suspension mechanism is proved. The radial and axial suspension forces are then calculated by the finite element method. The experimental prototype SHMB is finally designed and constructed. The stable suspension of the rotor is realized, and the suspension forces are measured. The results of the finite element calculation and experimental measurement verify the correctness of the mathematical models. [ABSTRACT FROM AUTHOR]

The flux-switching permanent-magnet double-rotor machine (FSPM-DRM) used for hybrid electric vehicles has attracted considerable attention due to the compact structure and high torque density. Compared with conventional machine, the FSPM-DRM suffers from more severe thermal problems in its inner rotor. This paper aims to make an accurate prediction of the performances and temperature distributions in the FSPM-DRM. First, the eddy current loss in windings with an improved analytical method is discussed and the results are validated by those from a 2-D finite-element (FE) model. With the obtained power losses, the lumped-parameter scheme considering end effect is compared with a 3-D FE thermal model to predict the temperature in each part of the FSPM-DRM at hybrid driving mode, in which both yield similar results. Then the maximum temperatures of different parts at the rated load and 160% load under various operational modes are simulated. Some experimental results are reported, validating the numerical and simulated results. [ABSTRACT FROM AUTHOR]

This paper presents the comparison of linear primary permanent magnet vernier (LPPMV) machine and linear vernier hybrid (LVH) machine. The LPPMV machine and the LVH machine both operate based on the magnetic gear principle, hence possessing the advantages of low speed and high thrust force density. In addition, both machines employ similar configurations between which the key difference is that a one-piece primary iron core is employed in the LPPMV machine instead of the modular cores in the LVH machine. Using the finite element method (FEM), the characteristics and performances of two machines are analyzed and compared. The results show that the LPPMV machine exhibits higher thrust force and lower cogging force. Finally, the FEM results are validated by experiments based on a prototype of the LPPMV machine. [ABSTRACT FROM AUTHOR]

In the permanent magnet (PM) machines, the Halbach PM (HPM) machine can offer higher performance than others, while they require more rare-earth PMs. Due to the high price of rare-earth PMs, such as NdFeB and SmCo magnets, the cost has become a serious drawback of the HPM machine. To overcome this disadvantage, a new fault-tolerant HPM (FTHPM) machine by mixing rare-earth PM and ferrite magnets is proposed in this paper. The proposed machine can be a good candidate for many applications because of low price and stable supply of ferrite magnets. Furthermore, the lumped parameter magnetic circuit method is used to analyze the proposed FTHPM machine. In addition, the finite element method is adopted to verify the effectiveness of the theoretical analysis. [ABSTRACT FROM AUTHOR]