This book, designed for a one-term first course in electric machines, is a revised and updated version of Nasar and Unnewehr's "Electromechanics and Electric Machines", second edition, published in 1983. The text has been revised and updated, adding new chapter problems and worked-out examples. A distinct feature of the book is that incremental-motion electromechanical systems form the subject of the last chapter, logically leading to a planned volume on machine dynamics.
Table of Contents
INTRODUCTION Types of Rotating Machines Efficiency, Energy, and Losses Methods of Analysis Ratings and Limitations on Electric Machines Economic Considerations References MAGNETIC CIRCUITS AND TRANSFORMERS Review of Electromagnetic Field Theory Magnetic Materials Magnetic Losses Magnetic Circuits Ampere's Law Applied to a Magnetic Circuit Differences Between Magnetic and Electronic Circuits Faraday's Law and Induced Voltage Energy Relations in a Magnetic Field Inductance Transformers References Problems DC MACHINES The Faraday Disk and Faraday's Law The Heteropolar of Conventional DC Machine Constructional Details Classification According to Forms of Excitation Performance Equations Amature Reaction Reactance Voltage and Commutation Voltage Buildup in a Shunt Generator Generator Characteristics Motor Characteristics Starting and Control of Motors Losses of Efficiency Tests on DC Machines References Problems SYNCHRONOUS MACHINES Some Construction Details Magnetomotive Forces and Fluxes Due to Amature and Field Windings Synchronous Speed Synchronous Generator Operations Synchronous Motor Operation Certain Realistic Considerations Operating Characteristics of a Synchronous Machine Salient Pole Synchronous Machines References Problems INDUCTION MACHINES Operation of a Three-Phase Induction Motor Slip Development of Equivalent Circuits Performance Calculations Approximate Equivalent Circuit From Test Data Performance Criteria of Induction Motors Speed Control of Induction Motors Starting of Induction Motors Induction Generators Single-Phase Induction Motors References Problems ELECTROMECHANICAL SYSTEMS Mechanical Forces Due to Magnetic Fields Energy Conservation and Energy Conversion The Force Equation Current and Flux Variations Dynamics of Electromechanical Systems Electrical Equivalent Circuits Doubly and Multiply Excited Systems Instantaneous, Average, and Root-Mean-Square Values of Forces References Problems Appendix I: Unit Conversion Appendix II: Magnet Wire Table for Single Film-Coated Round Wire Index