In this paper an approach of ferromagnetic shimming for permanent MRI magnet is presented. It is designed to reduce unhomogeneity of magnetostatic field of permanent magnet to meet the stringent requirement for MRI applications. An optimal configuration of ferromagnetic pieces is generated through calculation according to the initial field map and the demanded final homogeneity specifications. ...

The hysteresis motor is so named because it is producing mechanical torque utilizing the phenomenon of hysteresis. The rotor of a hysteresis motor is a cylindrical tube of high hysteresis loss permanent magnet material without windings or slots. This paper presents the design of a hysteresis permanent magnet motor using the finite element method. The rotor of the machine consists of 36% Cobalt ...

Tendencies in development of wind power industry including direct-drive small-scale wind power plants and generators have been analyzed. Synchronous generators with permanent magnet excitation for direct-drive wind power turbines are described. Primary magnetic field distribution and effect of armature reaction have been studied for design of a low-speed multipole permanent-magnet synchronous g...

Electrical motors drive a variety of loads in today’s world. Almost every industrial process relies on some kind of electrical motors and generators. There exist billions electric motors used in different applications all over the world. Majority of them are small fractional HP motors use in household appliances. However, they used about 5% of the electricity used by the motors. Three phase mot...

The considered converter-fed permanent magnet motor could alternatively be operated in two basically different states − the vector control mode or alternatively the brushless dc, also known as electronically commutated mode. Several quality aspects concerning the system performance have been comparatively investigated in practical as well as theoretical manner. Focus is thereby given to the num...

Permanent magnet (PM) machines with tooth coil windings are designed and analyzed. We study how the slot wedge material affects the behavior of PM losses when using tooth coil windings, which generate a significant air gap flux density harmonic content. The losses and cogging torques of a surface permanent magnet rotor and an interior permanent magnet rotor are compared in no-load and load situ...

‎in this paper, we investigate the chaotic behaviors of the fractional-order permanent magnet synchronous motor (pmsm) system. the necessary condition for the existence of chaos in the fractional-order pmsm system is deduced and an active controller is developed based on the stability theory for fractional systems. the presented control scheme  is simple and flexible, and it is suitable both fo...