Multiple objective genetic algorithms (MOGAs) simultaneously optimize a control law and geometrical features of a set of homopolar magnetic bearings (HOMB) supporting a generic flexible, spinning shaft. The minimization objectives include shaft dynamic response (vibration), actuator mass and total actuator power losses. Levitation of the spinning rotor and dynamic stability are constraint condi...

This paper considers the robust control of an active radial magnetic bearing system, having a homopolar, external rotor topology, which is used to support an annular fiber composite flywheel rim. A first-order dynamical compensator, which uses only position feedback information, is used for control, its design being based on a linearized one-dimensional second-order model which is treated as an...

AbstructThe p synthesis design method was evaluated for a flexible rotor magnetic bearing system with a five-axis-control system using both simulations and experiments. After modeling the full-order system using the finite element method, we obtained a reduced-order model in the modal domain by truncating the flexible modes. After choosing appropriate weighting functions with respect to frequen...

Active magnetic bearings can be implemented with frequency band-reject filtering that decreases the bearing stiffness and damping at a small bandwidth around a chosen frequency. The control scheme has been used for reducing a rotor dynamic force, such as an imbalance force, transmitted to the bearing stator. This study reveals that the scheme creates additional system vibration modes at the sam...

.Abstract – The goal of this research was to evaluate the potential of homopolar electrodynamic magnetic bearings for flywheel energy storage systems (FESSs). The primary target was a FESS for Low Earth Orbit (LEO) satellites, however, the design can also be easily adapted for Earth-based applications. The main advantages of Homopolar Electrodynamic Bearings compared to more conventional Active...

There is a growing demand for magnetic suspension, combined with electromagnetic propulsion, especially in the field of high accuracy twoor three-dimensional positioning. No mechanical wear, dust free operation, and (ultra) high vacuum compatibility are strong motivations to at least consider the application of magnetic bearings. This paper presents a novel Planar Active Magnetic Bearing [PAMB]...

Conventional Active Magnetic Bearings (AMB) are operated using a bias current (or flux) to achieve greater linearity and dynamic capability. Bias, however, results in undesirable rotating losses and consequent rotor heating. In this paper, optimal control of a magnetic bearing without bias is investigated. A single degree-of-freedom system consisting of a mass and two opposing electromagnets is...

The paper considers three issues in flexible rotor and magnetic bearing systems, namely control of rotor vibration, control of transmitted forces, and prevention of rotor contact with auxiliary bearings. An adaptive multi-objective optimization method is developed to tackle these issues simultaneously using a modified recursive open loop adaptive controller. The proposed method involves automat...

A 250 kW / 5 kWh engineering prototype Flywheel Energy Storage System (FESS) was designed, fabricated and component tested by Adelwitz Technologiezentrum GmbH (ATZ) and L-3 Communications Magnet Motor GmbH (MM). A heavy – load vertical 0.6 ton rotor is suspended totally magnetically by an HTS radial-passive bearing on the top together with a PM bearing at the bottom. Further features are the fl...

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...