E-Book, Englisch, 439 Seiten
ISBN: 978-1-4987-0915-6
Verlag: CRC Press
Format: PDF
Kopierschutz: Adobe DRM (»Systemvoraussetzungen)
Highlighting the essence of electromagnetic field (EMF) theory and its correlation with electrical machines, this book:
- Reviews Maxwell’s equations and scalar and vector potentials
- Describes the special cases leading to the Laplace, Poisson’s, eddy current, and wave equations
- Explores the utility of the uniqueness, generalized Poynting, Helmholtz, and approximation theorems
- Discusses the Schwarz–Christoffel transformation, as well as the determination of airgap permeance
- Addresses the skin effects in circular conductors and eddy currents in solid and laminated iron cores
- Contains examples relating to the slot leakage inductance of rotating electrical machines, transformer leakage inductance, and theory of hysteresis machines
- Presents analyses of EMFs in laminated-rotor induction machines, three-dimensional field analyses for three-phase solid rotor induction machines, and more
Electromagnetics for Electrical Machines makes an ideal text for postgraduate-level students of electrical engineering, as well as of physics and electronics and communication engineering. It is also a useful reference for research scholars concerned with problems involving electromagnetics.
Zielgruppe
Students of electrical, electronics, and communication engineering and physics, as well as research scholars concerned with problems involving electromagnetics.
Autoren/Hrsg.
Fachgebiete
- Technische Wissenschaften Elektronik | Nachrichtentechnik Elektronik Mikrowellentechnik
- Technische Wissenschaften Elektronik | Nachrichtentechnik Nachrichten- und Kommunikationstechnik Drahtlostechnologie
- Technische Wissenschaften Energietechnik | Elektrotechnik Energieverteilung, Stromnetze
- Technische Wissenschaften Energietechnik | Elektrotechnik Elektrotechnik
Weitere Infos & Material
Foreword
Preface
Authors
Introduction
Introduction
Field Approach
Domain of Machines
Review of Field Theory
Field Theorems
Uniqueness Theorem
Poynting Theorem
Approximation Theorem
Problem of Slotting
Eddy Current Phenomena
Poly-Phase Induction Machines
Laminated Iron Cores
Un-Laminated Iron Cores
Simulation of Armature Winding
Case Studies
Numerical Techniques
Finite Element Method
Analytical Techniques
References
Review of Field Equations
Introduction
Maxwell’s Equations in Integral Form
Maxwell’s Equations in Point Form
General Equations for One Type of Field
Maxwell’s Equations for Fields in Moving Media
Scalar Electric and Magnetic Potentials
Vector Magnetic Potential
Periodic Fields, Field Equations in Phasor Form
Retarded Potentials
Continuity Equation and Relaxation Time
A Rear Window View
References
Theorems, Revisited
Introduction
Uniqueness Theorem
Uniqueness Theorem for Laplace and Poisson Equations
Uniqueness Theorem for Vector Magnetic Potentials
Uniqueness Theorem for Maxwell’s Equations
Helmholtz Theorem
Generalised Poynting Theorem
Components of Power Flow
Components of Force
Approximation Theorems
Approximation Theorem for Laplacian Field
Approximation Theorem for Vector Magnetic Potential
Approximation Theorem for Eddy Current Equation
References
Laplacian Fields
Introduction
Potential Distribution for Rectangular Double-Slotting
Tooth-Opposite-Tooth Orientation
Tooth-Opposite-Slot Orientation
Arbitrary Orientation of Tooth and Slot
Air-Gap Permeance
Modelling for Aperiodical Field Distributions
Tooth-Opposite-Tooth Orientation
Tooth-Opposite-Slot Orientation
Arbitrary Orientation of Two Teeth
Fringing Flux for Tooth-Opposite-Tooth Orientation with Small Air Gap
Schwarz–Christoffel Transformation
Air-Gap Field of a Conductor Deep Inside an Open Slot
Schwarz–Christoffel Transformation (z-Plane to w-Plane)
Magnetic Field near Armature Winding Overhang
Surface Current Density
Magnetic Field Intensity
References
Eddy Currents in Magnetic Cores
Introduction
Eddy Current Machines (Solid Rotor Induction Machines)
Two-Dimensional Model
Eddy Currents in Large Plates Due to Alternating Excitation Current
Single-Phase Excitation
Poly-Phase Excitation
Eddy Currents in Cores with Rectangular Cross-Sections
Eddy Currents in Cores with Triangular Cross-Sections
Eddy Currents in Cores with Regular Polygonal Cross-Sections
Cores with Triangular Cross-Sections
Cores with Hexagonal Cross-Sections
Cores with Octagonal Cross-Sections
Eddy Currents in Circular Cores
Distribution of Current Density in Circular Conductors
Eddy Currents in Laminated Rectangular Cores
References
Laminated-Rotor Polyphase Induction Machines
Introduction
Two-Dimensional Fields in Anisotropic Media
Cage or Wound Rotor Induction Machines
Rotor Parameters
Induction Machines with Skewed Rotor Slots
Air-Gap Field
Fields in the Anisotropic Rotor Region
Determination of Arbitrary Constants
References
Un-Laminated Rotor Polyphase Induction Machines
Introduction
Tooth-Ripple Harmonics in Solid-Rotor Induction Machines
Physical Description
Field Distribution in Stator Slots
Field Distribution in the Air Gap
Field Distribution in the Solid Rotor
Machine Performances
Three-Dimensional Fields in Solid- Rotor Induction Machines
Idealised Model
Field Distributions
Effects of Finite Machine Length
Effect of Different Rotor and Stator Lengths
Performance Parameters
References
Case Studies
Introduction
Slot Leakage Inductance for Conductors in Open Slots
Physical Configuration
Current Density Distribution
Vector Magnetic Potential
Flux Density
Inductance
Leakage Inductance of Transformers
Physical Configuration
Current Density Distribution
Vector Magnetic Potential
Magnetic Flux Density
Arbitrary Constants
Leakage Inductance
Field Theory of Hysteresis Machines
Simplifying Assumptions
Field Distributions
Induction Machine Action
Hysteresis Machine Action
Impact of Different Parameters
Single-Phase Induction Motors with Composite Poles
Simplifying Assumptions
Idealised Machine Structure
Field Distribution
Transient Fields in Plates Due to Type 2 Impact Excitations
Current Impact Excitation
Voltage Impact Excitation
References
Numerical Computation
Introduction
Numerical Analysis
Computational Errors
Numerical Stability
Domain of Numerical Analysis
Values of Functions
Equations and Systems of Equations
Eigen-Value or Singular Value Problems
Optimisation Problem
Differential Equations
Numerical Integration
Software
Types of Equations
Relations without Summation or Integration
Relations Involving Simple Summations
Summations Leading to Simultaneous Linear Algebraic Equations
Further Reading
Appendices
Hilbert Transform
Evaluation of Integrals Involved in Equations 4.52 and 4.54
Evaluation of Integrals Involved in Equations 4.61 through 4.63
Evaluation of Integrals Involved in Equations 4.76a, 4.82b and 4.83b
Evaluation of Arbitrary Constants Involved in Section 5.9
Current Sheet Simulation of Stator Winding