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Detent force in permanent-magnet (PM) linear machines is caused by both end effect and slot effect. Segregation of the detent force into its end-effect and slot-effect components is helpful to better analysis and design. For conventional PM linear machines, the end-effect component of detent force can be easily calculated in a related slotless linear machine model, where the slot effect is eliminated. However, the slotless model is not applicable to permanent-magnet flux-switching (PMFS) linear machines, where the magnets and core teeth are set together on either a same stator or a same mover. This is because the PMFS machines cannot work at all without the teeth or slots. Therefore, a new method for segregating the detent force in the PMFS linear machines is proposed in this paper. Since a linear machine can be considered as a part of a particular rotary machine with large radius, and furthermore, cogging torque in the PM rotary machine is caused by the slot effect only, thereby the slot-effect component of the detent force in the PMFS linear machine can be calculated from the cogging torque in a related rotary machine, while the residual of the detent force is the end-effect component. Both finite element analysis (FEA) and experimental results show that the proposed method works well for the PMFS linear machines. [ABSTRACT FROM AUTHOR]

High-torque and low-speed electrical drives are often employed for applications where mechanical gearing cannot be accommodated. On the other hand, permanent-magnet (PM) gear has drawn significant attention from both academies and industries due to the conspicuous merits, such as reduced acoustic noise, maintenance free, improved reliability, precise peak torque transmission capability, and inherent overload protection. In this paper, a magnetic-geared PM brushless motor is presented. It is a novel low-speed and high-torque motor which merges the advantages of conventional PM brushless motor and PM gear. Its topology and operation principle are introduced. Some techniques are employed to optimize and improve the motor performance, while the validity of the proposed techniques is verified with finite-element analysis. Moreover, an alternative operation condition, which can further reduce the motor speed and increase its output torque, is proposed and analyzed. [ABSTRACT FROM AUTHOR]

Presents information on a simple and effective method for computing electromagnetic fields in three-dimensional (3-D) inhomogeneous dielectronic bodies. Detailed information on the method; Information on how the discrete system is solved; Multiplication requirements between the transpose of the system matrix and a vector; Details on the numerical results.