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This paper presents the design and evaluation of an Outer-Rotor Permanent-Magnet Flux-Switching (ORPM-FS) machine. A brief overview of relevant operating principles is given first. To realize the design objectives of high-torque capability, low-torque ripple, high efficiency, and high reliability, a new multilevel design optimization method is proposed to conduct the multi-objectives optimization. Finally, a prototype machine is built to verify the validity of the proposed design method and machine performance.

This paper introduces a high torque density permanent magnet (PM) machine for direct driving application, which adopts two V-shape tangential alternately magnetizing PM pieces in one stator pole in the brushless PM machine. The machine is optimized and the performance is compared with different PM dimensions and validated by experiment. The results indicate that the proposed machine benefits from reduced PM usage, improved torque density, and torque per magnetic volume, compared with the conventional flux-switching permanent magnet (FSPM) machine.

The flux-switching permanent-magnet double-rotor machine (FSPM-DRM) used for hybrid electric vehicles (HEVs) has attracted considerable attention due to the compact structure. This paper aims to make an accurate prediction of the performances in the FSPM-DRM. The machine topology is firstly introduced. By using the finite element method (FEM), the electromagnetic performances considering losses and temperature rise are analyzed. Finally, the PM demagnetization of the FSPM-DRM machine is studied, which indicates that the partial demagnetization will occur in the PMs. And the FEM results are verified by the tests on the prototype machine.

A lumped-parameter (LP) thermal model is presented for a flux-switching permanent-magnet double-rotor machine (FSPM-DRM) used for hybrid electric vehicles (HEVs), which has attracted attention due to the compact structure. The model provides the steady-state thermal solution to derive the temperatures at different parts of the machine, including the temperatures in the stator windings and the temperatures of the magnets. Temperature-dependent thermal properties of the materials used in the machine construction as well as the stator resistance and consequently copper losses require temperature update in accurate design of the machine. Therefore, an iterative coupled electromagnetic and thermal design program is proposed in this paper. A l-kW/l-kW FSPM-DRM prototype machine is designed and manufactured. Tests performed on the designed machine verify that the defined thermal resistance network has a high ability to predict the nodal temperatures accurately.

In this paper, the structure and operation principle of a slice hybrid magnetic bearing (HMB) with two radial air-gaps are analyzed, and the mathematical model of radial suspension force is deduced. Then, the magnetic paths are analyzed, and the radial suspension force is calculated by finite element method. Finally, the experimental prototype HMB is designed and constructed, where waveforms of stable suspension and antiinterference experiment are tested. The theory analysis, simulation and experimental results have shown that the proposed slice HMB can achieve stable suspension.

A novel bearingless permanent magnet slice motor (NBSMPM) with double air-gaps is proposed. In this motor, the stator includes left stator core and right magnetic bridge. The rotor is placed between the left stator core and magnetic bridge. First, the motor configuration and operation principle are analyzed, and the mathematical model of radial suspension forces are deduced using the equivalent magnetic circuit method. Then, the designed parameters are used in simulation and the magnetic path is analyzed by the finite element method. The experimental prototype motor is designed and control system is constructed to verify the suspension mechanism and mathematical model of the proposed motor.

In this paper, the structure and suspension mechanism of a slice five degrees of freedom (DOF) hybrid magnetic bearing (HMB) are proposed. The mathematical models of radial suspension force is deduced using equivalent magnetic circuit method. Then, the parameters of slice five DOF-HMB are designed. The magnetic paths are analyzed, and the relationships between the radial suspension force and the control winding current are calculated. In addition, the relationships between the axial suspension force and the axial displacement are calculated. Finally, the experimental prototype slice five DOF-HMB is designed. The waveforms of radial displacements and radial suspension force are both measured. The theory analysis and simulation results have shown that the proposed slice five DOF-HMB can achieve stable suspension.

In this paper, a novel bearingless permanent magnet slice motor is introduced. Both stator and rotor are made of double slice structure. An axial magnetized permanent magnet ring is placed in the stator core. Biased flux forms the closed path through the stator core, air gap, rotor core. The suspension force is produced by the interaction between the biased flux and suspension control flux. The motor structure and operation principle are analyzed, and the mathematical models of radial suspension forces are deduced using the equivalent magnetic circuit method. The 3D finite element analysis is used to verify the structure and mathematical models.