The coercive field and angular dependence of the coercive field of single-grain Nd2Fe14B permanent magnets are computed using finite element micromagnetics. It is shown that the thickness of surface defects plays a critical role in determining the reversal process. For small defect thicknesses reversal is heavily driven by nucleation, whereas with increasing defect thickness domain wall de-pinn...

This paper deals with the finite element estimation of cogging torque oscillations that occur in multipole permanent magnets synchronous wind generators. The numerical analysis is carried out using a 2D plane-parallel finite element model of the machine and afterward a more elaborated 3D model able to take into account the skewing of the stator slots. The numerical results are discussed and com...

This study deals with the demands of traction motor design process in where not only the application set some design limits but also the control method set its own boundaries. It is a demanding task to design a traction application in where the driving speed varies from low speed up to field weakening area. Permanent Magnet (PM) synchronous reluctance motors are often used in traction applicati...

A surface integration method for modeling of permanent magnets in 3-D space using edge nite elements is presented, where the value of the coercive magnetic forceH c is integrated only over the entire surface area of the permanent magnet. This allows direct computation of the equivalent source current values, which are afterwards assigned to the surface edges of the permanent magnet. The main ad...

This paper presents three dimensional study of a ferrofluid seal, its centering effect and its static capacity. Thus, a method based on a potential energy criterion has been put forward to study the seal shape. But such a use of ferrofluid seals is interesting only if the magnetic field created by the permanent magnets saturates totally the ferrofluid. Two cylindrical structures consisting of t...

The purpose of the magnet is to provide a uniform magnetic field at all points in the bore of the magnet to align mobile protons within the patient. The strength of the magnetic field is measured in units of testa or gauss-1.0 T equals 10 000 G. The magnetic field produced by the magnet is typically 30 000 times stronger than the magnetic field of the earth. Because it is not possible to obtain...

Spherical neodymium-iron-boron magnets are permanent magnets that can be assembled into a variety of structures owing to their high magnetic strength. A one-dimensional chain of these magnets responds to mechanical loadings in a manner reminiscent of an elastic rod. We investigate the macroscopic mechanical properties of assemblies of ferromagnetic spheres by considering chains, rings and chira...

We present our simulated initial magnetization curves for nanostructured permanent magnets based on a simple hybrid model. The model assumes that the reversible change in the magnetization curves obeys the Stoner–Wohlfarth (SW) model while the irreversible part can be attributed to the motion of the transition region (TR), which is a domainwall-like magnetic moment distribution formed in the gr...