In recent years a number of rotary machines with Active Magnetic Bearings have been designed in order to eliminate the lubricant medium, vibration and noise, and to achieve high velocities and loads. These systems are complicated due to the construction of mechanical, electrical and electronic circuits. A wide range analysis is required during the design procedure – from the construction stage ...

Adaptive back stepping control (ABC) is originally applied to a linearized model of an active magnetic bearing (AMB) system. Our control goal is to regulate the deviation of the magnetic bearing from its equilibrium position in the presence of an external disturbance and system uncertainties. Two types of ABC methods are developed on the AMB system. One is based on full state feedback, for whic...

Acknowledgments My special thank goes to my advisor Dr. Marcio S. de Queiroz. I thank him for all his continued support in all stages of this project. I would also like to extend my sincere gratitude to my committee members Dr. Kemin Zhou and Dr. Yitshak Ram for their valuable support and guidance. Abstract A solution to the problem of AMB control with reduced electrical power losses will be pr...

In this paper the development of mathematical model of voltage-input and current-input active magnetic bearing (AMB) system in deterministic form is presented. The AMB system, which is open-loop unstable and highly coupled due to nonlinearities inherited in the system such as gyroscopic effect and mass imbalance, requires a dynamic controller that can stabilize the system. In order to synthesiz...

In this paper, we address the problem of controlling an active magnetic bearing with reduced ohmic power losses. A solution is proposed which introduces an exponentially decaying bias ßux in the nonlinear control law. To avoid control singularities, the closed-loop system is exponentially stabilized at a faster rate than the bias decay. In the steady state, the proposed controller has zero bias...

A rotor supported on active magnetic bearings (AMBs) is levitated inside an air gap by electromagnets controlled in feedback. In the event of momentary loss of levitation due to an acute exogenous disturbance or external fault, reestablishing levitation may be prevented by unbalanced forces, contact forces, and the rotor’s dynamics. A novel robust control strategy is proposed for ensuring levit...

Active magnetic bearings enable contactless operation and can therefore be used for supporting rotors spinning at high speeds. However, the rotational speed in conventional reluctance-force-based magnetic bearing topologies is limited, which is mainly due to high rotor losses and limited force control bandwidths. In this paper, a prototype of a self-bearing motor is presented, which overcomes s...

In this paper, a design technique is proposed for a disturbance feedforward compensation control to attenuate disturbance responses in an active magnetic bearing system, which is subject to base motion. To eliminate the sensitivity of model accuracy to disturbance responses, the proposed design technique is an experimental feedforward compensator, developed from an adaptive estimation, by means...

– This report presents some improvements to the radial stiffness of a magnetic suspension in a new ventricular assist device (VAD) that has been jointly developed by Dante Pazzanese Cardiology Institute (IDPC) and Escola Politecnica of São Paulo University. This VAD has a novel architecture that distinguishes it from other known VADs. In this, the rotor that impels and pressurizes the blood has...

The paper has describes the complete design and investigation processes of permanent magnetic bearing. The passive magnetic bearing (PMB) rotor suspension rig employing no active control components was calculated, designed, constructed and tested. In order to increase the radial passive magnetic bearing stiffness, the Halbach-array configuration was used. The main purpose of the work was develo...