Permanent MAGNETs (PM), which are one of the most vulnerable and important components of permanent MAGNET machines, are at risk of deMAGNETization for reasons such as overheating and corrosion. One of the most critical tasks of engineers in the industry is to prevent the machine's operation in the deMAGNETization condition and replace the machine's defective PMs as much as possible. DeMAGNETization causes linkage flux reduction, electroMAGNETic force changes, and machine heating. This paper presents a new approach for deMAGNETized PM diagnosis in a permanent MAGNET linear synchronous machine using wavelet packet transform. Due to the high sensitivity to the flux changes, the electromotive force signal was selected as a detection signal. By examining this method in different deMAGNETization cases, it is determined that this method has a proper performance. In this paper, the finite element software (Maxwell) and MATLAB were used to simulate the machine and analyze the data, respectively.

Cogging torque reduction of axial flux permanent MAGNET brushless dc (PMBLDC) motor is an important issue which demands attention of machine designers during design process. This paper presents MAGNET notching technique to reduce cogging torque of axial flux PMBLDC motor designed for electric vehicle application. Reference axial flux PMBLDC motor of 250 W, 150 rpm is designed with 48 stator slots and 16 rotor poles of NdFeb type permanent MAGNET without notching. Three dimensional finite element modeling and analysis is performed to obtain cogging torque profile of initially designed reference machine. Notches are created on permanent MAGNETs and its influence on cogging torque is analyzed with 3-D finite element modeling and analysis. It is analyzed that MAGNET notching is an effective technique to reduce cogging torque of axial flux PMBLDC motor.

Brushless permanent MAGNET surface inset machines are interested in industrial applications due to their high efficiency and power density. MAGNET segmentation is a common technique in order to mitigate cogging torque and electroMAGNETic torque components in these machines. An accurate computation of MAGNETic vector potential is necessary in order to compute cogging torque, electroMAGNETic torque, back electromotive force and self/mutual inductance. A 2D analytical method for MAGNETic vector potential calculation in inner rotor brushless segmented surface inset permanent MAGNET machines is proposed in this paper. The analytical method is based on the resolution of Laplace and Poisson equations as well as Maxwell equation in a quasi-Cartesian polar coordinate by using sub-domain method. One of the main contributions of the paper is to derive an expression for the MAGNETic vector potential in the segmented PM region by using hyperbolic functions. The developed method is applied on the performance computation of two prototype surface inset MAGNET segmented motors with open circuit and on load conditions. The results of these models are validated through FEM method.

Proton therapy with accelerator systems has been used in the last 30 years to destroy tumors by producing highly energetic ion beams. Although different systems have been introduced and designed to accelerate ions, the superconductive cyclotron accelerator is one of the most efficient treatment equipment compared to other systems. In this research, the design study of Iranian Medical Proton Superconducting Cyclotron (IMSIC-250) was considered. The IMSIC-250 system is a fixed frequency cyclotron with four spiral sector MAGNETs designed to accelerate protons in the form of H2+ particles up to 250 MeV/amu. In the current study, the design process of the superconducting MAGNET and coil structure was reported. The 3D model of the spiral pole MAGNET alongside the superconducting coil was modeled. The main characteristics of the cyclotron MAGNET and coil structure were also studied. It was demonstrated that the designed MAGNET is capable of producing the desired isochronous MAGNETic field in order to accelerate protons up to 250 MeV. The stability of the acceleration process was achieved by a nonnegative value of flutter over the acceleration of particles. For coil structure, the current density over coil turns and the applied force was modeled. The flutter concept was also used to investigate the stability of the acceleration process. It was discovered that flutter has a nonnegative value when compared to particle acceleration. Finally, the stability of a MAGNETic coil against applied MAGNETics (Lorentz) force was investigated and it was demonstrated that the applied MAGNETic field on the coil would not have a destructive influence on the superconducting structure of the coil.

In this research, MAGNETostriction and thermal expansion of polymer-bonded Nd4Fe77.5B18.5 nano-composites are studied using strain gage method. The effect of sintering on samples is also studied. X-ray diffraction patterns and SEM pictures of the original and annealed samples show that the grain size of α-Fe and Fe3B soft MAGNETic phases in amorphous matrix increases and mechanical hardness of the samples improves after annealing at 700 °C for 20 min.. Overall behavior of the thermal expansion is similar for samples in both cases, with about 20% larger coefficient for the annealed one. The MAGNETostriction measurements show huge magnitudes in order of 10-4 at the presence of relatively weak external MAGNETic fields. The magnitude of MAGNETostriction noticeably decreases after annealing which can originate from two different sources. MAGNETostriction of the original sample mainly originates from single particle interactions of Nd-sublattice in Nd2Fe14B phase, but the situation is very different for the annealed sample. The complicate variations of the MAGNETostrictive isotherms of the annealed sample are discussed based on the following three factors: internal stresses, MAGNETocrystalline anisotropy and mechanisms of coercivity.

An interior permanent MAGNET motor is a good option for traction application related to the induction motor and switched reluctance motor because of high mechanical rigidity and low deMAGNETization risk. the design of this kind of motor is attractive for engineer despise the implementation cost of them in high constant speed power range (cpsr) is high. In this paper using combination of two ideas i.e. non-conventional air bridge and segmented permanent MAGNET a optimal design has been proposed. In this paper non-conventional air bridge is used for reducing the permanent MAGNET volume. The genetic algorithm has been applied to the goal function. Simulation results show the good performance of optimal design related the conventional design.

The use of permanent MAGNETs in the structure of electric machines, in addition to simplifying design and construction by reducing losses, leads to increased efficiency in the motor. However, the MAGNETic material can be damaged by failure caused by faults such as short circuits in the electronic driver of the motor. MAGNETs containing samarium and neodymium are completely brittle and easy to crack. These elements are also very vulnerable due to their crystalline structure and grain texture. MAGNET defect fault is one of the most common faults in permanent MAGNET machines. In this paper, a permanent MAGNET synchronous motor (PMSM) with a MAGNET defect fault is simulated using the finite element method. Moreover, Prony's method is modified by the matrix pencil method for the estimation of the component created in the stator current. The frequency spectrum of MAGNETic flux density and stator current in both faulty and healthy modes are extracted and fault detection is done through a modified Prony's method.

This paper reviews the current state of the double-stator permanent MAGNET vernier (DS-PMV) machine technology. At first, the recent advances in PMV machines are presented. In the following, the classification of various PMV machines' configuration is elucidated. In general, this review covers the principle of better understanding of the novel PMV machines' topologies using different windings configurations, flux modulation poles and stator/rotor structures.