Electric Machinery Fundamentals (4th Edition) - Stephen J. Chapman PDF

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ELECTRIC MACHINERY FUNDAMENTALS ELECTRIC MACHINERY FUNDAMENTALS FO URTH EDITION Stephen J. Chapman BAE SYSTEMS Australia Higher Education Boston Burr Ridge, IL Dubuque, IA Madison , WI New York San Francisco SI. l ouis Bangkok Bogota Caracas Kuala l umpur Lisbon London Madrid Mexico City Mi lan Mon...

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ELECTRIC MACHINERY FUNDAMENTALS

ELECTRIC MACHINERY FUNDAMENTALS FO URTH EDITION

Stephen J. Chapman BAE SYSTEMS Australia

Higher Education Boston Burr Ridge, IL Dubuque, IA Madison , WI New York San Francisco SI. l ouis Bangkok Bogota Caracas Kuala l umpur Lisbon London Madrid Mexico City Mi lan Montreal New Delhi Santiago Seoul Singapore Sydney Taipei Toronto

•

Higher Education

ELECTRIC M ACHINERY RJNDAMENTALS. FOURTH EDITION

Published by McGraw-H ill. a business unit of The McGraw-H ill Companies. Inc., 1221 Avenue of the Americas, New Yort. NY 10020. Copyright 0 2005, 1999. 1991. 1985 by The McGraw,Hill Companies. Inc. All rights reserved. No part of this publication may be reproduced or distributed in any form or by any means. or stored in a database or retrieval system. without the prior written con' sent of The McGraw-H ill Companies. Inc., including. but not limited to, in any network or other electronic storage or transmission. or broadcast for distance learning. Some ancillaries. including electronic and prim components. may not be available to customers out, side the United States. This book is printed on acid'free paper.

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ISBN 0--07- 246523--9 Publisher: Elizabeth A. Jones Senior sponsoring editor: Carlise Paulson Managing developmental editor: EmilyJ. Lupash Marketing manager: Val''"" R. Bercier Senior project manager: Sheila M. Frank Senior production supervisor: Laura Fuller Senior media project manager: Tammy Juran Senior designer: Da\·id W. Hash Lead photo research coordinator: Carrie K. Burger Compositor: GAC- Indianapolis Typeface: /0//2 Times Rotnlln Printer: R. R. Donnelley Crawfordsville. IN

Libmry of Co n ~ress

Gltalo~in~-in-l'ublic:ltion

Chapman. Stephen J . Electric machinery fundamentals / Stephen Chapman. p. em. Includes index. ISBN 0-07- 246523--9 I. E lectric machinery. I. T itle. T K2000.C46 2005 621.31 ·042---dc22

2003065174 CIP

www.mhhe.oom

4th ed.

Data

THIS WORK IS DEDICATED WITH LOVE TO MY MOTHER, LOUI SE G. CHAPMAN , ON THE OCCASION OF HER EIGHTY-RFfH BIRTHDAY.

ABOUT THE AUTHOR

Ste phen J. Chapman received a B.S. in Electrical Engineering from Lo uisiana State University ( 1975) and an M.S.E. in Electrical Engineering from the University of Central Florida ( 1979), and pursued further graduate studies at Rice University. From 1975 to 1980, he served as an offi cer in the U.S. Navy, assigned to teach electrical engineering at the U.S. Naval Nuclear Power School in Orlando, Florida. From 1980 to 1982, he was affiliated with the University of Houston, where he ran the power systems program in the College of Technology. From 1982 to 1988 and from 1991 to 1995, he served as a me mber of the

technical stafT of tile Massachusetts Institute of Technology's Lincoln Laboratory, both at the main facility in Lexington, Massachusetts, and at the fie ld site on Kwajalein Atoll in the Republic of the Marshall Islands. While there, he did research in radar signal processing systems. He ultimate ly became the leader of four large operational range instrumentation radars at the Kwajalein field site (TRADEX, ALTAIR, ALCOR, and MMW). From 1988 to 1991 , Mr. Chapman was a research engineer in Shell Development Company in Houston, Texas, where he did seismic signal processing research. He was also affiliated with the University of Houston, where he continued to teach on a part-time basis. Mr. Chapman is currently manager of syste ms modeling and operational analysis for BAE SYSTEMS Australia, in Me lbourne. Mr. Chapman is a senior member of the Institute of Electrical and Electronic Engineers (and several of its component societies) . He is also a me mber of the Association for Computing Machinery and the Institutio n of Engineers (Australia).

vu

BRIEF CONTENTS

Chapter 1

Introduction to Machinery Principles

Chapter 2

Transformers

Chapter 3

Introduction to Power Electronics

152

Chapter 4

AC Machinery Fundamentals

230

65

Chapter 5 Synchronolls Generators

267

Chapter 6

Synchronolls Motors

346

Chapter 7

Induction Motors

380

Chapter 8

DC Machinery Fundamentals

473

Chapter 9

DC Motors and Generators

533

Chapter 10

Single-Phase and Special-Purpose Motors

633

Appendix A

Three-Phase Circuits

68 1

Appendix B

Coil Pitch and Distributed Windings

707

Appendix C

Salient-Pole Theory ofSynchronolls Machines

727

Appendix D

Tables of Constants and Conversion Factors

737

"

TABLE OF CONTENTS

Chapter 1 Introduction to Machinery Principles 1.1

1.2

Electrical Machines, Transformers, and Daily Life A Note on Units and Notation

2

Notation

1.3

Rotational Motion, Newton's Law, and Power Relationships

3

Angular Position (J I Angular Velocity w / Angular Acceleration a / Torque T / Newton 's Law o/ Rotation I

Work W Power P

I..

The Magnetic Field

8

Production of a Magnetic Field / Magnetic Circuits / M agnetic Behavio r 01 Ferromagnetic Materials I En ergy Losses in a Ferromagnetic Core 1.5 1.6 1.7

I."

Faraday's Law-Induced Voltage from a Time-Changing Magnetic Field Produ cti on of Indu ced Force on a Wire Induced Voltage on a Conductor Moving in a Magnetic Field The Linear OC Machine- A Simple Example

28 32

34 36

Sta rting the Linear DC M achine / The linear DC M achine as a M otor I The Linea r DC Machine as a Generato r I Starting Problems with the Linear Machine

I..

Real, Reactive, and Apparent Power in AC Circuits

47

Alternative Fon ns of the Power Equations I Complex Power I The Relationships beflt'een Impedance Angle, Current Angle, and Power I The Power Triangle 1.10

Summary Q uestions Problems References

53 54 55 64

"

XII

TABLE OF CONTENTS

Cha pter 2 2. 1 2.2 2.3

Transformers

65

Wh y Transfonn ers Are Im portant to Modern Life Types and Constru cti on of Transformers The Ideal Transfonner

66 66 68

Power in an Ideal Transfo rmer I Impedance TransfornUltion through a Transfornler I Analysis of Circuits Containing Ideal Transformers

2.4

Theory of Operation of Real Single-Phase Transformers

76

The Voltage Ratio across a Transformer I The Magnetization Cu rrent in a Real Transformer I The Cu rrent Ratio on a Transformer and the Dot Conrention

2.5

The Equivalent Circ uit of a Transformer

86

The Exact Equivalent Circuit of a Real Transformer I ApproxinUlte Equivalent Circuits of a Transfo rmer I Determining the Values of Components in the Transfo n ner Model

2.6 2.7

The Per-Unit System of Measurements Transfonner Voltage Regulation and Efficiency

94 100

The Transformer Phasor Diagram I Transfo n ner Efficiency

2.8 2.9

Transfonner Taps and Voltage Regul ation The Autotransfonner

108 109

Voltage and Current Relationships in an Autotransformer I The Apparent Power Rating Advantage ofAutotransfornlers I The Internal Impedance of an Autotransformer 2.10

Three-Phase Transfonners

11 6

Three-Phase Transformer Connections I The Per-Unit System fo r Three-Phase Transformers 2. 11

Three-Phase Transfonn ati o n Using Two Transformers

126

The Open-il (or V-V) Connection I The Open-"3'e-OpenDelta Connection I The Scott- T Connection I The ThreePhase T Connection 2. 12

Transfonner Ratings and Related Problems

134

The Voltage and Frequency Ratings of a Transformer I The Apparent Power Rating of a Transfornler I The Problem of Cu rrent Inrnsh I The Transformer Nameplate 2. 13 2. 14

Instnun ent Transformers Swnmary

140 142

Q uesti ons Problems Refe rences

143 144 15 1

TABLE OF CONTENTS

Chapter 3 3.1

XlU

Introduction to Power Electronics

152

Power Electronic Components

152

The Diode / The Two- Wire Thyristor or PNPN Diode / The Three-Wire Thyristor of SCR / The Gate Turnoff Thyristor / The DlAC / The TRIA C / The Power Transistor / The Insulated-Gate Bipolar Transistor / Power atui Speed Comparison of Power Electronic Components

3.2

Basic Rectifier Circuits

163

The Half-Wave Rectifier / The Full-Wave Rectifier / The Three-Phase Half-Wave Rectifier / Th e Three-Phase FullWave Rectifier / Filtering Rectifier Output

3.3

Pulse Circuits

17 1

A Relaxation Oscillator Using a PNPN Diode / Pulse Synchronization

3.4

Voltage Variation by AC Phase Control

177

AC Phase Controlfora DC Load Drivenfrom an AC Source / AC Phase Angle Control for an AC Load / The Effect of Inductive Loads on Phase Angle Control

3.5

DC-to-DC Power Control-Choppers

186

Forced Commutation in Chopper Circuits / SeriesCapacitor Commutation Circuits / Parallel-Capacitor Commutation Circuits

3.6

Inverters

193

The Rectifier / External Commutation lnverters / SelfCommutation Inverters / A Single-Phase Current Source Inverter / A Three-Phase Current Source lnverter / A Three-Phase Voltage Source Inverter / Pulse-Width Modulation lnverters

3.7

Cycloconverters

209

Basic Concepts / Noncirculating Current Cycloconverters / Circulating Current Cycloconverters

3.' 3.'

Chapter 4 4.1

Q uestions Problems References

218 221 223 223 229

AC Machinery Fundamentals

230

A Simple Loop in a Uniform Magnetic Field

230

Hannonic Problems Summary

The Voltage Induced in a Simple Rotating Loop / The Torque lnduced in a Cur rent-Cart}'ing Loop

XI V

TABLEOF CONTENTS

4.2

The Rotating Magnetic Fie ld

238

Proof of the Rotating Magnetic Field Concept I The Relationship between Electrical Frequency and the Speed of Magnetic Field Rotation I Reversing the Direction of Magnetic Field Rotation

4.3 4.4

Magnetomoti ve Force and Flux Distribution on AC Machines Induced Voltage in AC Machines

246 250

The Induced Voltage in a Coil on a Two-Pole Stator I The Induced Voltage in a Th ree-Phase Set of Coils I The RMS Voltage in a Three-Phase Stator

4.5 4.• 4.7

Induced Torque in an AC Machine Wmding Insulation in an AC Machine AC Machine Power Flows and Losses

255 258 26 1

The Losses in AC Machines I The Power-Flow Diagram

4.S 4.9

Chapter 5 5. 1 5.2 5.3 5.4 5.5 5.• 5.7

Voltage Reg ulation and Speed Regulation Swnmary

262 264

Q uestions Problems References

265 265 266

Synchronous Generators

267

Synchronous Generator Construction The Speed of Rotation of a Synchronous Generator The Internal Generated Voltage of a Synchronous Generator The Equivalent Circuit of a Synchronous Generator The Phasor Diagram of a Synchronous Generator Power and Torque in Synchronous Generators Measuring Synchronous Generator Model Parameters

267 272 273 274 279 280 283

The Short-Circuit Ratio

5.8

The Synchronous Generator Operating Alone

288

The Effect of Load Changes on Synchronous Generator Operating Alone I Example Problems

5.9

Parallel Operation of AC Generators

299

The Conditions Requiredfor Paralleling I The General Procedure fo r Paralleling Generators I Frequency-Power and Voltage-Reactive Power Characteristics of a Synchronous Generator I Operation of Generators in Parallel with Large Power Systems I Operation of Generators in Parallel with Other Generators of the Same Size

5.10

Synchronous Generator Transients

Transient Stability of Synchronous Generators I Short-Circuit Transients in Synchronous Generators

319

TABLE OF CONTENTS

5.11

Synchronous Generator Ratings

XV

326

The Voltage, Speed, and Frequency Ratings / Apparent Power atui Power-Factor Ratings / Synchronous Generator Capability CUf1Jes / Short-Time Operation and Sef1Jice Factor

5. 12

Chapter 6 6.1

Questions Problems References

336 337 338 345

Synchronous Motors

346

Basic Principles of Motor Operation

346

Summary

The Equiralent Circuit of a Synchronous Motor / The Synchronous Motor from a Magnetic Field Perspective

6.2

Steady-State Synchronous Motor Operation

350

The Synchronous Motor Torque-Speed Characteristic CUf1Je / The Effect of Load Changes on a Synchronous Motor / The Effect of Field Changes on a Synchronous Motor / The Synchronous Motor atui Power, Factor Correction / The Synchronous Capacitor or Synchronous Condenser

6.3

Starting Synchronous M otors

364

Motor Starting by Reduced Electrical Frequency / Motor Starting with an utemal Prim e Mover / Motor Starting by Using Amortisseur Windings / The Effect of Amortisseur Windings on Motor Stability

6.4 6.5 6.6

Chapter 7 7.1 7.2

Questions Problems References

37 1 372 373 374 374 379

Induction Motors

380

Induction Motor Construction Basic Induction Motor Concepts

380 384

Synchronous Generators and Synchronous Motors Synchronous Motor Ratings Summary

The Development of Induced Torque in an ltuiuction Motor / The Concept of Rotor Slip / The Electrical Frequency on the Rotor

7.3

The Equivalent Circuit of an Induction Motor The Transformer Model of an Induction Motor / The Rotor Circuit Model/The Final Equiralent Circuit

388

XVI

TABLE OF CONTENTS

7.4

Power and Torque in Induction Motors

394

Losses and the Pml'er-Flow Diagram I Power atui Torque in an Indu ction Motor I Separating the Rotor Copper Losses and the Pmwr Converted in an lnduction Motor S Equivalent Cirr:uit

7.5

Induction Motor Torque-Speed Characteristics

401

lnduced Torque from a Physical Statuipoint IThe Derivation of the lnduction Motor ltuiuced-Torque Equation I Comments on the Induction Motor Torque-Speed Cun'e I Maximum (Pullout) Torque in an ltuiuction Motor

7.•

Variations in Induction Motor Torque-Speed Characteristics

416

Control of Motor Characteristics by Cage Rotor Design I Deep-Bar and Double-Cage Rotor Designs I lnduction Motor Design Classes

7.7 7.8

Trends in Induction Motor Design Starting Induction Motors

426 430

lnduction Motor Starting Circuits

7.9

Speed Control of Induction Motors

434

lnduction Motor Speed Control by Pole Changing I Speed Control by Changing the Line Frequency I Speed Control by Changing the Line Voltage I Speed Control by Changing the Rotor Resistance 7. 10

Solid-State Induction Motor Drives

444

Frequency (Speed) Adjustment I A Choice of Voltage and Frequency Patterns I Independently Adjustable Acceleration atui Deceleration Ramps I Motor Protection 7. 11

Detennining Circuit Model Parameters

452

The No-Load Test I The DC Test for Stator Resistance I The Locked-Rotor Test 7. 12

The Induction Generator

460

The lnduction Generator Operating Alone I lnduction Generator Applications 7. 13 7. 14

Chapter 8

Q uestions Problems Rereren ces

464 466 467 468 472

DC Machinery Fundamentals

473

Induction Motor Ratings Swnmary

8. 1 A Simple Rotating Loop between Curved Pole Faces

473

TABLE OF CONTENTS

XVU

The lliltage lnduced in a Rotating Loop / Getting DC Voltage out of the Rotating Loop / The Induced Torque in the Rotating Loop

8.2 8.3

Commutation in a Simple Four-Loop IX Mac hine Commutation and Armature Construction in Real DC Machines

485 490

The Rotor Coils / Connections to the Commutator Segments / The Lap Winding / The Wave Winding / The Frog-Leg Winding

8.4

Problems with Conunut ation in Real Machines

502

Armature Reaction / L dildt Voltages / Solutions to the Problems with Commutation

8.5 8.6

The Internal Generated Voltage and Induced Torque Equations of Real DC Machines The Construction of DC Machines

514 518

Pole and Frame Construction / Rotor or Armature Constrnction / Commutator and Brushes / Winding Insulation

8.7

Power Flow and Losses in DC Machines

524

The Losses in DC Machines / The Power-Flow Diagram

8.8

Summary Questions Problems References

Chapter 9 9.1 9.2 9.3 9.4

527 527 527 530

DC Motors and Generators

533

Introduction to DC Motors The Equivalent Circuit of a IX Motor The Magnetization Curve of a DC Machine Separately Excited and Shunt IX Motors

533

535 536 538

The Ten ninal Characteristic of a Shunt DC Motor / Nonlinear Analysis of a Shunt DC Motor / Speed Control of Sh unt DC Motors / The Effect of an Open Field Circuit

9.5 9.6

The Pennanent-Magnet DC Motor The Series IX Motor

559 562

Induced Torque in a Series DC Motor / The Terminal Characteristic of a Series DC Motor / Speed Control of Series DC Motors

9.7

The Compounded DC Motor The Torque-Speed Characteristic of a Cum ulatively Compounded DC Motor / The Torque- Speed

568

XVIII

TABLE OF CONTENTS

Characteristic of a Differentially Compoutuied DC Motor / The Nonlinea r Analysis of Compo unded DC Motors / Speed Control in the Cumulatively Compoutuied DC Motor 9.8

DC Motor Starters

573

DC Motor Problems on Sta rting / DC Motor Starting Circuits 9.9

The Ward-Leonard System and Solid-State Speed Controllers

582

Protection Circuit Section / StartlStop Circuit Section / High.Power Electronics Section / Low-Power Electronics Section 9.10 9. 11 9. 12

DC Motor Efficiency Calculati ons Introduction to IX Generators The Separately Excited Gen...