Analysis and design of an active magnetic bearing

Dissertant

Abd al-Wahhab, Thamir Muhammad

University

University of Technology

Faculty

-

Department

Department of Electrical Engineering

University Country

Iraq

Degree

Ph.D.

Degree Date

2009

English Abstract

An active magnetic bearing (AMB) is an electromagnetic device that acts as a rion-contaci bearing and can be used as alternative to the conventional mechanical bearings due to its advanced features especially Lehigh-speed applications, This work considers the radial AMB through, the theoretical analyses, the design, the numerical analyses, and the control system.

Analytical methods based on the magnetic circuit's theory are adopted to develop the mathematical model of the radial AMB.

Two general algorithms are proposed, for the individual and the quadrant pole arrangements, and programmed using MAT LAB software package to compute analytically the basic magnetic parameters of the AMB.

Based on The mathematical model design algorithms are developed and programmed in MATLAB to enable designing the AMB geometry according to: performance requirements, design constraints, and free parameters chosen by the designer.

The design-program is implemented and tested for two sets of AMB input data.

Numerical finite element method (FEM) analyses are proposed using the powerful AKSY5 software package for the evaluation of AMB performance during the design process.

A two-dimension model is developed in AKSYS using the designed AMB geometry in order to investigate The distribution of magnetic field and forces in the model for the following analyses under consideration: steady state case including linear and non-linear analysis, transient state analysis, computation of inductance matrix and flux linkages to formulate the mathematical model of AMB dynamics, and finally optimizing the geometry of AMB.

AMB is unstable in its nature, and used in very high-speed applications thus the design and implementation of a suitable control system requires extensive investigation.

In tins work the AMB control problem is treated, and a proportional plus derivative plus intact (PID) control system is designed using the two degrees of freedom approach, and tested using V1ATLAB.

Also, some practical effects on system performance arc considered.

The results obtained consist of; the results of the analysis-pro-am, two designs of AMB geometry parameters determined by the design-program, and the results of implementing the FEM analysis programs on the two designed AMB models These results contain important details of the different types of analysis and for the different considered cases, with a thorough representation of the magnetic field and force distribution by-colored graphs or in table form These developed programs can be regarded as a powerful design tool to help the designer in performing complicated analysis in a relatively short time and less efforts.

Finally, the designed PID control system is simulated and tested using MATLAB / Simulink, in addition lo the simulation of some practical effects to investigate then influence on system performance.

Main Subjects

Mechanical Engineering

Topics

• Mathematical models
• Electromagnetism
• Industrial applications
• Magnetic bearings

• APA
• MLA
• AMA

Language

English

Data Type

Arab Theses

Record ID

BIM-305220