This study is concerned with a three-pole active magnetic bearing (AMB) system assembly error and non-uniform flux distribution. The error, which the result of misalignment back-up stator AMB, induces strong nonlinear uncertainty in AMB dynamics. distribution, mainly due to material properties, manufacturing errors, etc., makes force model more complicated. A stable-levitation controller design...

We are developing a 50 kWh-class flywheel energy storage system as a national project, using a new axial superconducting magnetic bearing (Ax_SMB) technology. The project has started in FY2005 and will continue to FY2007. The Ax_SMB is composed of Fe core and superconducting coil, which are simply torus-shape. It generates strong restoring force in axial direction. It can realize non-contact le...

Zero-bias or low-bias control of AMB's is essential for the design of magnetic bearings with low power losses. This paper investigates the use of control Lyapunov functions (clf's) to solve the problem of global asymptotic stabilization for a zero-bias Active Magnetic Bearing (AMB). We use the cascade structure of the system to derive a clf for the AMB model which is then used to derive a stabi...

background: nowadays, magnetic nanoparticles (mnps) have received much attention because of their enormous potentials in many fields such as magnetic fluid hyperthermia (mfh). the goal of hyperthermia is to increase the temperature of malignant cells to destroy them without any lethal effect on normal tissues. to investigate the effectiveness of cancer therapy by magnetic fluid hyperthermia, fe...

Maxwell 3D of Ansoft software were used for this study. Ansoft’s solutions are based on a more general program using Maxwell’s equations. A simple analysis has been done for calculating the magnetic force interacted between two magnets of similar poles facing each other. The modeling in Anosoft has been described.

The idea behind Active Structural Acoustic Control (ASAC) is to actively influence the dynamics of a structure to reduce the radiated sound. In ASAC, the difficulty often lies in finding the relation between the structural vibration and the sound pressure in a certain point. The largest reduction in sound pressure level is not always obtained by reducing the vibration levels of one panel, inter...

Catcher bearings (CB) are an essential component for rotating machine with active magnetic bearings (AMBs) suspensions. The CB’s role is to protect the magnetic bearing and other close clearance component in the event of an AMB failure. The contact load, the Hertzian stress, and the sub/surface shear stress between rotor, races, and balls are calculated, using a nonlinear ball bearing model wit...

Flux coupling in heteropolar magnetic bearings permits remaining active coils to assume actions of failed coils to produce force resultants identical to the un-failed actuator. This fault-tolerant control usually reduces load capacity because the redistribution of the magnetic flux which compensates for the failed coils leads to premature saturation in the stator or journal. A distribution matr...