Inductances and forces of a three phase permanent magnet biased radial active magnetic bearing in dependence on the rotor eccentricity

2009 ◽  
Author(s):  
Erich Schmidt ◽  
Matthias Hofer
Keyword(s):  
Permanent Magnet ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Rotor Eccentricity ◽  
Three Phase

Commissioning and Control of the AMB Supported 3.5 kW Laboratory Gas Blower Prototype

2013 ◽  
Vol 198 ◽  
pp. 451-456 ◽  
Author(s):  
Rafał P. Jastrzębski ◽  
Alexander Smirnov ◽  
Katja Hynynen ◽  
Janne Nerg ◽  
Jussi Sopanen ◽  
...  
Keyword(s):  
Control System ◽  
Permanent Magnet ◽  
Induction Motor ◽  
Industrial Applications ◽  
Magnetic Bearing ◽  
Active Magnetic Bearing ◽  
Sensor Calibration ◽  
Full Potential ◽  
Disturbance Analysis ◽  
And Control

This paper presents the practical results of the design analysis, commissioning, identification, sensor calibration, and tuning of an active magnetic bearing (AMB) control system for a laboratory gas blower. The presented step-by-step procedures, including modeling and disturbance analysis for different design choices, are necessary to reach the full potential of the prototype in research and industrial applications. The key results include estimation of radial and axial disturbance forces caused by the permanent magnet (PM) rotor and a discussion on differences between the unbalance forces resulting from the PM motor and the induction motor in the AMB rotor system.

scholarly journals Performance Comparison of Analytical Models for Rotor Eccentricity: A Case Study of Active Magnetic Bearing

2020 ◽  
Vol 25 (2) ◽  
pp. 285-292
Author(s):  
Zhi Cao ◽  
Yunkai Huang ◽  
Baocheng Guo ◽  
Jianning Dong ◽  
Fei Peng
Keyword(s):  
Magnetic Bearing ◽  
Performance Comparison ◽  
Active Magnetic Bearing ◽  
Analytical Models ◽  
Rotor Eccentricity

scholarly journals Bearingless PM synchronous machine with zero-sequence current driven star point-connected active magnetic thrust bearing

2018 ◽  
Vol 4 (3) ◽  
pp. 5-25 ◽  
Author(s):  
Daniel Dietz ◽  
Andreas Binder
Keyword(s):  
Thrust Bearing ◽  
Lateral Force ◽  
Magnetic Bearing ◽  
Synchronous Machine ◽  
Active Magnetic Bearing ◽  
Three Phase ◽  
Zero Sequence ◽  
Force Ripple ◽  
Motor Operation ◽  
Modulation Degree

Common cylindrical bearingless drives require a separate thrust bearing, which is fed by a DC supply. Here, a technique is presented, which enables the feeding of the thrust bearing by an artificially generated zero-sequence current between the two star points of the two parallel windings in the bearingless PM synchronous machine. This way, no additional DC supply for an axial active magnetic bearing is needed. It is replaced by two three-phase inverters as stator winding supply, which are needed in any case to generate torque and lateral rotor force in the motor. This examination explains the technique of adapting the electric potential of the star points in two three-phase windings of the motor. The focus is on the determination of the operating area (maximum zero-sequence current and band width). It is constrained by the bearingless motor due to torque and lateral force ripple as well as additional eddy current losses. On the other hand, the DC link voltage and the modulation degree of the inverter for simultaneous motor operation as well as the bearing inductance limit the system dynamic. It is shown that the proposed technique is applicable for a modulation degree < 0.866, taking into account that other constraints by the bearingless machine and the inverter are mainly noncritical.

scholarly journals A new self-propelled magnetic bearing with helical windings

2016 ◽  
Vol 472 (2196) ◽  
pp. 20160579
Author(s):  
B. Shayak
Keyword(s):  
Permanent Magnet ◽  
Stiffness Matrix ◽  
Control Algorithm ◽  
High Efficiency ◽  
Permanent Magnet Synchronous Motor ◽  
Magnetic Bearing ◽  
High Load ◽  
Output Torque ◽  
Three Phase ◽  
Torque Angle

In this work, a design is proposed for an active, permanent magnet based, self-propelled magnetic bearing, i.e. levitating motor having the following features: (i) simple winding structure, (ii) high load supporting capacity, (iii) no eccentricity sensors, (iv) stable confinement in all translational dimensions, (v) stable confinement in all rotational dimensions, and (vi) high efficiency. This design uses an architecture consisting of a helically wound three-phase stator, and a rotor with the magnets also arranged in a helical manner. Active control is used to excite the rotor at a torque angle lying in the second quadrant. This torque angle is independent of the rotor's position inside the stator cavity; hence the control algorithm is similar to that of a conventional permanent magnet synchronous motor. It is motivated through a physical argument that the bearing rotor develops a lift force proportional to the output torque and that it remains stably confined in space. These assertions are then proved rigorously through a calculation of the magnetic fields, forces and torques. The stiffness matrix of the system is presented and a discussion of stable and unstable operating regions is given.

Design and Testing of a Permanent Magnet Biased Active Magnetic Bearing

1999 ◽  
Author(s):  
Ross W. Overstreet ◽  
George T. Flowers ◽  
Gyorgy Szasz
Keyword(s):  
Permanent Magnet ◽  
Permanent Magnets ◽  
Experimental Testing ◽  
Control Strategies ◽  
Active Vibration Control ◽  
Electrical Current ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Flux Flow

Abstract Magnetic bearings provide rotor support without direct contact. There is a great deal of current interest in using magnetic bearings for active vibration control. Conventional designs use electrical current to provide the bias flux, which is an integral feature of most magnetic bearing control strategies. Permanent magnet biased systems are a relatively recent innovation in the field of magnetic bearings. The bias flux is supplied by permanent magnets (rather than electrically) allowing for significant decreases in resistance related energy losses. The use of permanent magnet biasing in homopolar designs results in a complex flux flow path, unlike conventional radial designs which are much simpler in this regard. In the current work, a design is developed for a homopolar permanent magnet biased magnetic bearing system. Specific features of the design and results from experimental testing are presented and discussed. Of particular interest is the issue of reduction of flux leakage and more efficient use of the permanent magnets.

Permanent Magnet Biased Bearing of Suspension System

2011 ◽  
Vol 383-390 ◽  
pp. 5529-5535
Author(s):  
Ming Zong ◽  
Xiao Kang Wang ◽  
Yang Cao
Keyword(s):  
Magnetic Field ◽  
Mathematical Model ◽  
Permanent Magnet ◽  
Power Amplifier ◽  
Model Simulation ◽  
Simulation Method ◽  
Magnetic Bearing ◽  
Magnetic Bearings ◽  
Active Magnetic Bearing ◽  
Simulation Results

PM (Permanent Magnet) biased magnetic bearing with PM to replace the magnetic field produced by electromagnet an Active Magnetic Bearing generated static bias magnetic field, it can reduce the power consumption of power amplifier to reduce the number of turns of magnet safety, reduce the volume of magnetic bearings, reducing electromagnetic coil operating current, thereby reducing the power amplifier power control system and heat sink size, magnetic bearings significantly reduce power loss, and fundamentally reduce the cost of bearing. In this paper, a kind of PM biased magnetic bearings, describes its structure and working principle, derived a mathematical model of magnetic bearing and magnetic circuit of PM biased magnetic bearings are calculated, given the specific PM biased magnetic bearing size and accordingly calculate the parameters of magnetic bearings. A magnetic model constructed using Simulink simulation method, and constructed using this method, magnetic bearing specific mathematical model simulation results show that the rotor position in the balance, X and Y decoupling between the control winding, while the deviation from equilibrium position time, X and Y control coupling between the windings, the simulation results and the calculation results.

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