Performance of Repulsive Type Magnetic Bearing System Under Nonuniform Magnetization of Permanent Magnet

Permanent magnet bearing system utilizes the repulsive forces between the stator and rotor permanent magnets (PM) for the levitation of the system and it results a simplified axial control scheme. A repulsive type magnetic bearing system based on the above principle was fabricated in our laboratory. Material characteristics and the configuration of the permanent magnets are the central component for this type of bearing system. Due to aging or as both the magnets are repelling each other, there will be demagnetization of the permanent magnet, resulting the field distribution along the magnet\u27s periphery nonuniform. In this paper the effect of this magnetization nonuniformity on the performance of the bearing system has been studied

Conveyance Test by Oscillation and Rotation to a Permanent Magnet Repulsive-Type Conveyor

Various applications of a single-axis controlled repulsive-type magnetic bearing have been proposed earlier. However, most conventional systems are equipped with a set of passive magnetic bearings and an active magnetic bearing. In this paper a new repulsive-type conveyor system with many passive magnetic bearing pairs is proposed. This system enables an easy rotation with negligible friction and soft conveyance by radial stiffness between the rotor and the stator permanent magnets. This paper also reports a conveyance test using ellipse motion of each shaft

Disturbance Attenuation and H∞ Control on Repulsive Type Magnetic Bearing

Repulsive Type Magnetic Bearing using permanent magnet for the lévitation and radial control makes the system cheap and simplified control scheme. But the system is prone to disturbance in the absence of any active control. This paper reports on the application of H°°control for robust stabilization and configuration of permanent magnet resulting in improved stiffness characteristics for disturbance attenuation in the radial direction of repulsive type magnetic bearing system. A laboratory prototype model and the controller around digital signal processor have been developed and experiments are carried out

The effect of non-uniform magnetization of permanent magnets on the performance of a repulsive type magnetic bearing system

A permanent magnet bearing (MB) system utilizing the repulsive forces operating between the stator and rotor permanent magnet for levitation and radial control has been fabricated in our laboratory, The consistency of the permanent magnet magnetization effects the continuous steady-state and dynamic performance of the system. Since both the magnets are repelling each other, there will be demagnetization of the magnetization of the permanent magnet. Due to demagnetization or ageing or manufacturing asymmetry, the field distribution may not be uniform along the periphery of the magnet. In this paper the effect of this magnetization non-uniformity on the performances of the bearing system has been studied