The Vernier PM (VPM) machine is known as a high-torque and low-speed drive solution suitable for direct-drive applications such as electric vehicles and wind turbines. The Consequent-Pole VPM (CP-VPM) machine is a special structure of VPM that introduces high-torque density as the conventional VPM by incorporating the significantly lower volume of PM materials. Despite the large body of recent research and many experiments concerning the conventional structure, the CP-VPM machine has received attention only by few publications. The paper presented the electromagnetic principles of flux modulation in the CP-VPM machine. The quantities of machine operation were evaluated using analytical equations and the performance of the mentioned machine was compared with that of the conventional machine. It was concluded that the torque density and back EMF of the proposed machine were much larger than those of the conventional machine and the torque pulsation magnitude was lower. However, the power factor was undesirably reduced due to higher spatial harmonic distortion of the CP rotor magnetic field and the presence of magnetic field components, which would not contribute to the flux modulation. Based on the spatial harmonic analysis, design modifications made for enhancing the operational characteristics of the CP-VPM machine were proposed and their effectiveness was verified by comparing the 2D-FE results with those of the conventional VPM machines.

Losses in electric machines produce heat and cause an efficiency drop. As a consequence of heat production, temperature rise will occur which imposes severe problems. Due to the dependence of electrical and mechanical performance on temperature, conducting thermal analysis for a special electric machine that has a compact configuration with poor heat dissipation capability is crucial. This paper aims to carry out the thermal analysis of an axial-field flux-switching permanent magnet (AFFSPM) machine for electric vehicle application. To fulfill this purpose, three-dimensional (3D) finite element analysis is performed to accurately derive electromagnetic losses in active components. Meanwhile, copper losses are calculated by analytic correlation in maximum allowable temperature. To improve thermal performance, cooling blades are inserted on the frame of AFFSPM, and 3D computational fluid dynamics (CFD) is developed to investigate thermal analysis. The effect of different housing materials, the external heat transfer coefficient, and various operating points on the components' temperature has been reported. Finally, 3-D FEA is used to conduct heat flow path and heat generation density.

A general framework for the development of a new generation of PM linear oscillating machine (PMLOM) using FE magnetic analysis suitable for short strokes is described in this paper. A microcontroller based IGBT inverter is developed for the control of thrust and oscillation frequency. The PMLOM can perform precision oscillation task with relatively low power dissipation. The use of powerful permanent magnet material such as Neodymium-Iron-Boron alloys has greatly improved the performance of the machine. The forces for aluminium mover embedded with rare earth permanent magnets are determined analytically and the results are validated extensively by comparison with finite element analyses.

This paper presents a design and optimization procedure for a dual-stator machine with a diametrically magnetized PM to improve the electromagnetic performance. First, analytical design equations are presented based on MEC analysis,they are used to design a basic dual-stator machine. Then, by applying an artificial intelligence algorithm, the machine is optimized to achieve high efficiency and torque density, and low pulsating torque for direct-drive applications. A quantitative comparison is performed between the optimized new machine and conventional dual-stator machines to evaluate the performances and improvements of the understudy machine. The machine performance, including air-gap flux density distribution, back electromotive force, electromagnetic torque, cogging torque, and torque ripple are analyzed by the finite element method. The analysis results have demonstrated that benefiting from its topology, the optimized dual-stator machine with diametrically magnetized PM has the comprehensively better performance, including higher torque density, higher efficiency, and lower torque ripple and cogging torque compared to conventional dual-stator machines.