Linear Synchronous Motors

Transportation and Automation Systems, Second Edition

Jacek F. Gieras, Zbigniew J. Piech, Bronislaw Tomczuk

• Publisher: CRC Press
• Year: 2018
• Print ISBN: 9781138582071
• eBook ISBN: 9781351833448
• Topic: Technology & Engineering
• Subtopic: Electrical Engineering & Telecommunications
• Index: Technology & Engineering

Considered to be the first book devoted to the subject, Linear Synchronous Motors: Transportation and Automation Systems, Second Edition evaluates the state of the art, demonstrating the technological innovations that are improving the design, construction, and performance of modern control systems. This new edition not only illustrates the development of linear synchronous motor drives, but it also discusses useful techniques for selecting a motor that will meet the specific requirements of linear electrical drives.

New Features for the Second Edition:

• Several updated and expanded sections, as well as two new chapters on FEM
• Even more numerical examples, calculations, and mathematical models
• Broadened target audience that includes researchers, scientists, students, and more

Evaluating trends and practical techniques for achieving optimal system performance, the authors showcase ready-to-implement solutions for common roadblocks in this process. The book presents fundamental equations and calculations used to determine and evaluate system operation, efficiency, and reliability, with an exploration of modern computer-aided design of linear synchronous motors, including the finite element approach. It covers topics such as linear sensors and stepping motors, magnetic levitation systems, elevators, and factory automation systems. It also features case studies on flat PM, tubular PM, air-cored, and hybrid linear synchronous motors, as well as 3D finite element method analysis of tubular linear reluctance motors, and linear oscillatory actuators.

With such an exceptional presentation of practical tools and conceptual illustrations, this volume is an especially powerful resource. It will benefit readers from all walks by providing numerical examples, models, guidelines, and diagrams to help develop a clear understanding of linear synchronous motor operations, characteristics, and much more.

1

Topologies and Selection

1.1 Definitions, Geometry, and Thrust Generation

Linear electric motors can drive a linear motion load without intermediate gears, screws, or crank shafts. A linear synchronous motor (LSM) is a linear motor in which the mechanical motion is in synchronism with the magnetic field, i.e., the mechanical speed is the same as the speed of the traveling magnetic field. The thrust (propulsion force) can be generated as an action of

• traveling magnetic field produced by a polyphase winding and an array of magnetic poles N, S,…,N, S or a variable reluctance ferromagnetic rail (LSMs with a.c. armature windings);
• magnetic field produced by electronically switched d.c. windings and an array of magnetic poles N, S,…,N, S or variable reluctance ferromagnetic rail (linear stepping or switched reluctance motors).

The part producing the traveling magnetic field is called the armature or forcer. The part that provides the d.c. magnetic flux or variable reluctance is called the field excitation system (if the excitation system exists) or salient-pole rail, reaction rail, or variable reluctance platen. The terms primary and secondary should rather be avoided, as they are only justified for linear induction motors (LIM) [63] or transformers. The operation of an LSM does not depend on, which part is movable and which one is stationary.

Traditionally, a.c. polyphase synchronous motors are motors with d.c. electromagnetic excitation, the propulsion force of which has two components: (1) due to the traveling magnetic field and d.c. current magnetic flux (synchronous component) and (2) due to the traveling magnetic field and variable reluctance in d- and q-axis (reluctance component). Replacement of d.c. electromagnets with permanent magnets (PMs) is common, except for LSMs for magnetically levitated vehicles. PM brushless LSMs can be divided into two groups:

• PM LSMs in which the input current waveforms are sinusoidal and produce a traveling magnetic field;
• PM d.c. linear brushless motors (LBMs) with position feedback, in which the input rectangular or trapezoidal current waveforms are precisely syn-chronized with the speed and position of the moving part.

Construct...

Table of contents

• Cover
• Title Page
• Copyright Page
• Contents
• Preface to the 2nd Edition
• About the Authors
• 1 Topologies and Selection
• 2 Materials and Construction
• 3 Theory of Linear Synchronous Motors
• 4 FEM Analysis
• 5 Hybrid and Special Linear Permanent Magnet Motors
• 6 Motion Control
• 7 Sensors
• 8 High-Speed Maglev Transport
• 9 Building and Factory Transportation Systems
• 10 Industrial Automation Systems
• Appendix A Magnetic Circuits with Permanent Magnets
• Appendix B Calculations of Permeances
• Appendix C Performance Calculations for PM LSMs
• Appendix D Field-Network Simulation of Dynamic Characteristics of PM LSMs
• Symbols and Abbreviations
• References
• Patents
• Index