Electric powertrain energy systems, power electronics drives for hybrid, electric fuel cell vehicles ( TQL )

Electric Powertrain



Electric Powertrain
Energy Systems, Power Electronics and Drives for Hybrid,
Electric and Fuel Cell Vehicles

John G. Hayes
University College Cork, Ireland

G. Abas Goodarzi
US Hybrid, California, USA


This edition first published 2018
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Library of Congress Cataloging-in-Publication Data
Names: Hayes, John G., 1964– author. | Goodarzi, G. Abas, author.
Title: Electric powertrain : energy systems, power electronics and drives for
hybrid, electric and fuel cell vehicles / by John G. Hayes, G. Abas Goodarzi.
Description: Hoboken, NJ : John Wiley & Sons, 2018. | Includes
bibliographical references and index. |
Identifiers: LCCN 2017029458 (print) | LCCN 2017043878 (ebook) |
ISBN 9781119063667 (pdf) | ISBN 9781119063674 (epub) |
ISBN 9781119063643 (cloth)
Subjects: LCSH: Electric vehicles–Power supply. | Hybrid electric
vehicles–Power trains. | Power electronics.
Classification: LCC TL220 (ebook) | LCC TL220 .H39 2018 (print) |
DDC 629.25/02–dc23
LC record available at />Cover Design: Wiley

Cover Images: (Bus) Image supplied by G. Abas Goodarzi; (Concept Car)
© -M-I-S-H-A-/iStockphoto; (Mars Rover) © NASA
Set in 10/12pt Warnock by SPi Global, Pondicherry, India
10 9 8 7 6 5 4 3 2 1


To all who have contributed to the electrification of the automobile for a cleaner,
more sustainable future.



vii

Contents
Preface xix
Acknowledgments xxi
Textbook Structure and Suggested Teaching Curriculum
About the Companion Web Site xxiv
Part 1
1

1.1
1.1.1
1.1.2
1.1.3
1.2
1.2.1
1.2.1.1
1.2.2
1.2.2.1

1.3
1.3.1
1.3.2
1.4
1.4.1
1.5
1.6
1.6.1
1.6.2
1.6.2.1
1.7
1.7.1
1.7.2

Vehicles and Energy Sources

xxii

1

Electromobility and the Environment 3
A Brief History of the Electric Powertrain 4
Part I – The Birth of the Electric Car 4
Part II – The Resurgent Electric Powertrain 5
Part III – Success at Last for the Electric Powertrain 6
Energy Sources for Propulsion and Emissions 10
Carbon Emissions from Fuels 12
Example: Carbon Dioxide Emissions from the Combustion of Gasoline
Greenhouse Gases and Pollutants 13
The Impact of NOx 14

The Advent of Regulations 15
Regulatory Considerations and Emissions Trends 17
Heavy-Duty Vehicle Regulations 18
Drive Cycles 19
EPA Drive Cycles 19
BEV Fuel Consumption, Range, and mpge 24
Carbon Emissions for Conventional and Electric Powertrains 25
Well-to-Wheel and Cradle-to-Grave Emissions 27
Emissions due to the Electrical Grid 28
Example: Determining Electrical Grid Emissions 28
An Overview of Conventional, Battery, Hybrid, and Fuel Cell Electric
Systems 29
Conventional IC Engine Vehicle 30
BEVs 30

12


viii

Contents

1.7.3
1.7.3.1
1.7.3.2
1.7.3.3
1.7.4
1.7.5
1.7.6
1.8

2

2.1
2.1.1
2.1.2
2.1.2.1
2.1.2.2
2.1.3
2.1.3.1
2.1.3.2
2.1.3.3
2.1.3.4
2.1.4
2.1.5
2.1.5.1
2.1.5.2
2.1.5.3
2.1.6
2.1.6.1
2.2
2.2.1
2.2.2
2.2.2.1
2.2.3
2.2.3.1
2.2.3.2
2.3

HEVs 31

Series HEV 32
Parallel HEV 32
Series-Parallel HEV 33
FCEV 33
A Comparison by Efficiency of Conventional, Hybrid, Battery,
and Fuel Cell Vehicles 34
A Case Study Comparison of Conventional, Hybrid, Battery,
and Fuel Cell Vehicles 35
A Comparison of Automotive and Other Transportation
Technologies 36
References 37
Further Reading 38
Problems 38
Assignments 39
Vehicle Dynamics 40
Vehicle Load Forces 40
Basic Power, Energy, and Speed Relationships 41
Aerodynamic Drag 42
Example: Aerodynamic Drag 43
Example: Aerodynamic Drag and Fuel Consumption 45
Rolling Resistance 45
The Ford Explorer Recall 45
The A-Class Mercedes in the 1990s 46
The Tesla Model S in 2013 46
Example: Rolling Resistance 46
Vehicle Road-Load Coefficients from EPA Coast-Down Testing 46
Battery Electric Vehicle Range at Constant Speed 49
Example: Plot of BEV Range Versus Speed 49
Example: Estimate of BEV Range 50
Example: Effect of Auxiliary Loads on Range 50

Gradability 51
Example: Downgrade Force and Regeneration 51
Vehicle Acceleration 52
Regenerative Braking of the Vehicle 54
Traction Motor Characteristics 54
Example: 2015 Nissan Leaf Rated Speed 55
Acceleration of the Vehicle 57
Time-Step Estimation of Vehicle Speed 57
A Simplified Equation Set for Characterizing Acceleration by Ignoring
Load Forces 57
Simple Drive Cycle for Vehicle Comparisons 60
References 62
Further Reading 62
Problems 62


Contents

Sample MATLAB Code 63
Assignment: Modeling of a BEV
3

3.1
3.1.1
3.1.1.1
3.1.2
3.1.3
3.1.3.1
3.1.3.2
3.1.3.3

3.1.4
3.1.5
3.1.5.1
3.1.6
3.1.6.1
3.1.6.2
3.1.6.3
3.1.6.4
3.1.6.5
3.2
3.2.1
3.2.1.1
3.2.1.2
3.2.2
3.3
3.3.1
3.3.2
3.3.3
3.4
3.4.1
3.4.2
3.4.2.1
3.4.3
3.4.3.1
3.4.4
3.4.4.1
3.4.5
3.4.5.1
3.4.5.2
3.4.6

3.4.6.1
3.5

66

Batteries 68
Introduction to Batteries 68
Batteries Types and Battery Packs 68
Recent EVs and Battery Chemistries 70
Basic Battery Operation 73
Basic Electrochemistry 74
Lead-Acid Battery 74
Nickel-Metal Hydride 75
Lithium-Ion 76
Units of Battery Energy Storage 76
Capacity Rate 77
Example of the 2011 Nissan Leaf Battery Pack 78
Battery Parameters and Comparisons 79
Cell Voltage 79
Specific Energy 80
Cycle Life 80
Specific Power 81
Self-Discharge 81
Lifetime and Sizing Considerations 81
Examples of Battery Sizing 84
Example: BEV Battery Sizing 84
Example: PHEV Battery Sizing 85
Battery Pack Discharge Curves and Aging 86
Battery Charging, Protection, and Management Systems 88
Battery Charging 88

Battery Failure and Protection 88
Battery Management System 89
Battery Models 90
A Simple Novel Curve Fit Model for BEV Batteries 92
Voltage, Current, Resistance, and Efficiency of Battery Pack 95
Example: Determining the Pack Voltage Range for a BEV 96
A Simple Curve-Fit Model for HEV Batteries 96
Example: Determining the Pack Voltage Range for a HEV 97
Charging 97
Example: Fast Charging a Battery Pack 98
Determining the Cell/Pack Voltage for a Given Output\Input Power
Example: Battery Discharge 99
Example: Battery Charge 100
Cell Energy and Discharge Rate 100
Example: Cell Capacity 101
Example: The Fuel Economy of a BEV Vehicle with a Fixed
Gear Ratio 102
References 105

99

ix


x

Contents

Further Reading 106
Problems 106

Appendix: A Simplified Curve-Fit Model for BEV Batteries
4

4.1
4.1.1
4.1.2
4.2
4.2.1
4.2.1.1
4.2.2
4.2.2.1
4.2.3
4.3
4.3.1
4.3.2
4.3.3
4.3.4
4.4
4.5
4.6

5

5.1
5.2
5.2.1
5.3
5.3.1
5.3.2
5.3.3

5.3.4
5.4
5.4.1
5.4.2
5.4.3
5.4.4

108

Fuel Cells 111
Introduction to Fuel Cells 111
Fuel Cell Vehicle Emissions and Upstream Emissions 113
Hydrogen Safety Factors 113
Basic Operation 114
Fuel Cell Model and Cell Voltage 116
Example: No-Load and Load Voltages of a PEM Fuel Cell 117
Power and Efficiency of Fuel Cell and Fuel Cell Power Plant System 118
Example: Full-Load Power and Efficiency of PEM Fuel Cell Stack 118
Fuel Cell Characteristic Curves 119
Sizing the Fuel Cell Plant 120
Example: Sizing a Fuel Cell 121
Toyota Mirai 121
Balance of Plant 121
Boost DC-DC Converter 122
Fuel Cell Aging 122
Example: Sizing Fuel Cell System for Heavy Goods Tractor–Trailer
Combination 124
Example: Fuel Economy of Fuel Cell Electric Vehicle 126
References 129
Problems 129

Assignments 130
Conventional and Hybrid Powertrains 131
Introduction to HEVs 131
Brake Specific Fuel Consumption 134
Example: Energy Consumption, Power Output, Efficiency,
and BSFC 135
Comparative Examples of Conventional, Series, and Series-Parallel
Hybrid Systems 138
Example: Fuel Economy of IC Engine Vehicle with Gasoline or Diesel
Engine 138
Example: Fuel Economy of Series HEV 144
Example: Fuel Economy of Series-Parallel HEV 146
Summary of Comparisons 148
The Planetary Gears as a Power-Split Device 148
Powertrain of 2004 Toyota Prius 150
Example: CVT Operating in Electric Drive Mode (Vehicle Launch and
Low Speeds) 151
Example: CVT Operating in Full-Power Mode 153
Example: CVT Operating in Cruising and Generating Mode 154
References 155


Contents

Problems 155
Assignments 156
Part 2
6

6.1

6.1.1
6.1.2
6.1.3
6.1.4
6.2
6.2.1
6.2.2
6.2.3
6.2.4
6.2.5
6.2.6
6.2.7
6.3
6.3.1
6.3.2
6.3.3
6.3.4
6.4

7

7.1
7.2
7.3
7.3.1
7.3.2
7.3.3
7.3.4
7.4
7.5

7.5.1
7.6
7.6.1
7.6.2
7.7
7.7.1
7.8

Electrical Machines

159

Introduction to Traction Machines 161
Propulsion Machine Overview 161
DC Machines 162
AC Machines 163
Comparison of Traction Machines 167
Case Study – Mars Rover Traction Motor 169
Machine Specifications 170
Four-Quadrant Operation 170
Rated Parameters 171
Rated Torque 172
Rated and Base Speeds 172
Rated Power 172
Peak Operation 173
Starting Torque 173
Characteristic Curves of a Machine 173
Constant-Torque Mode 173
Constant-Power Mode 174
Maximum-Speed Mode 174

Efficiency Maps 174
Conversion Factors of Machine Units 176
References 177
The Brushed DC Machine 178
DC Machine Structure 178
DC Machine Electrical Equivalent Circuit 180
DC Machine Circuit Equations 182
No-Load Spinning Loss 183
No-Load Speed 184
Maximum Power 184
Rated Conditions 184
Power, Losses, and Efficiency in the PM DC Machine 185
Machine Control using Power Electronics 186
Example: Motoring using a PM DC Machine 186
Machine Operating as a Motor or Generator in Forward or
Reverse Modes 189
Example: Generating/Braking using a PM DC Machine 190
Example: Motoring in Reverse 191
Saturation and Armature Reaction 191
Example: Motoring using PM DC Machine and Machine Saturation
Using PM DC Machine for EV Powertrain 193

192

xi


xii

Contents

7.8.1
7.9
7.9.1
7.10
7.11
7.11.1
7.11.2
7.11.3

Example: Maximum Speeds using PM DC Machine
Using WF DC Machine for EV Powertrain 195
Example: Motoring using WF DC Machine 197
Case Study – Mars Rover Traction Machine 199
Thermal Characteristics of Machine 201
Example of Steady-State Temperature Rise 202
Transient Temperature Rise 203
Example of Transient Temperature Rise 203
References 204
Problems 204

8

Induction Machines

8.1
8.1.1
8.1.2
8.2
8.2.1

8.2.2
8.3
8.3.1
8.3.2
8.3.3
8.3.4
8.3.4.1
8.3.4.2
8.3.4.3
8.4
8.4.1
8.4.1.1
8.4.2
8.4.2.1
8.4.2.2
8.4.2.3
8.5
8.5.1
8.5.2
8.5.3
8.5.3.1

194

206
Stator Windings and the Spinning Magnetic Field 207
Stator Magnetic Flux Density 209
Space-Vector Current and the Rotating Magnetic Field 211
Induction Machine Rotor Voltage, Current, and Torque 216
Rotor Construction 216

Induction Machine Theory of Operation 216
Machine Model and Steady-State Operation 219
Power in Three-Phase Induction Machine 222
Torque in Three-Phase Induction Machine 223
Phasor Analysis of Induction Motor 225
Machine Operation When Supplied by Current Source 225
Example: Motoring at Rated Speed using Induction Machine 228
Example: Motoring at Rated Speed using Induction
Machine – Ignoring Leakage 231
Example: Generating at Rated Speed using Induction Machine 232
Variable-Speed Operation of Induction Machine 234
Constant Volts per hertz Operation 235
Example: Maintaining a Constant Volts per Hertz 235
Variable-Speed Operation 235
Example: Field-Weakened Motoring at Twice the Rated Speed using
Induction Machine 236
Example: Stall/Start-Up using Induction Machine 238
Effects of Rotor Heating 240
Machine Test 240
DC Resistance Test 240
Locked-Rotor Test 240
No-Load Test 242
Example of Machine Characterization 243
References 244
Further Reading 244
Problems 245
Sample MATLAB Code 246

9

Surface-Permanent-Magnet AC Machines

9.1
9.1.1

Basic Operation of SPM Machines
Back EMF of a Single Coil 249

249

249


Contents

9.1.2
9.1.2.1
9.1.2.2
9.1.3
9.1.3.1
9.2
9.2.1
9.2.2
9.2.2.1
9.2.3
9.2.3.1
9.2.4
9.2.4.1
9.2.5
9.2.5.1

9.2.6

Back EMF of Single Phase 250
The Experimental Back EMF 253
Distributed Winding 253
SPM Machine Equations 253
Example: Phase Voltage of SPM Machine 255
Per-Phase Analysis of SPM Machine 255
Per-Phase Equivalent Circuit Model for SPM Machine 256
Phasor Analysis of SPM Machine 257
Example: Motoring using SPM Machine 260
Machine Saturation 263
Example: Motoring using SPM Machine 263
SPM Torque–Speed Characteristics 264
Example: Determining No-Load Speed 265
High-Speed Operation of SPM Machine above Rated Speed 266
Example: Motoring using SPM Machine in Field Weakening 269
Machine Characteristics for Field-Weakened Operation 270
References 272
Further Reading 273
Problems 273
MATLAB Code 274

10

Interior-Permanent-Magnet AC Machine

10.1
10.2
10.2.1

10.3
10.3.1
10.3.2
10.4
10.4.1
10.4.2
10.4.3
10.5
10.5.1
10.6
10.6.1
10.6.2

276
Machine Structure and Torque Equations 276
d- and q-Axis Inductances 278
Example: Estimating the d-axis and q-axis Inductances for 2004
Toyota Prius Motor 281
IPM Machine Test 281
No-Load Spin Test 282
DC Torque Test 282
Basic Theory and Low-Speed Operation 286
Example: Motoring at Rated Condition 287
Maximum Torque per Ampere (MTPA) 289
Maximum Torque per Volt (MTPV) or Maximum Torque
per Flux (MTPF) 289
High-Speed Operation of IPM Machine 289
Example: Motoring at High Speed using IPM Machine 289
dq Modeling of Machines 291
Constant Current Transformation 292

Constant Power Transformation 294
References 295
Further Reading 295
Problems 296
Assignments 298
Part 3

Power Electronics

11

DC-DC Converters

11.1

Introduction

301

301

299

xiii


xiv

Contents

11.2
11.2.1
11.2.2
11.3
11.3.1
11.3.1.1
11.3.1.2
11.3.1.3
11.3.1.4
11.3.2
11.3.2.1
11.3.3
11.3.3.1
11.4
11.4.1
11.4.1.1
11.4.1.2
11.4.2
11.4.2.1
11.4.3
11.4.3.1
11.5
11.5.1
11.5.1.1
11.5.1.2
11.5.1.3
11.5.1.4
11.5.2
11.5.2.1
11.6

11.6.1
11.6.2
11.6.2.1
11.7
11.7.1

Power Conversion – Common and Basic Principles 304
The Basic Topologies 306
The Half-Bridge Buck-Boost Bidirectional Converter 307
The Buck or Step-Down Converter 307
Analysis of Voltage Gain of Buck Converter in CCM 309
Analysis of Buck Converter in CCM 311
Determining Low-Voltage Capacitor RMS Current 312
Capacitor Voltages 314
Example: Designing Buck Converter for CCM Operation 315
BCM Operation of Buck Converter 317
Example of Buck in BCM 317
DCM Operation of Buck Converter 319
Example: Buck Converter in DCM Operation 324
The Boost or Step-up Converter 325
Analysis of Voltage Gain of Boost Converter in CCM 326
Analysis of Boost Converter in CCM 327
Example: Analyzing Boost for CCM Operation 329
BCM Operation of Boost Converter 330
Example: Boost Converter in BCM 332
DCM Operation of Boost Converter 332
Example: Boost Converter in DCM Operation 335
Power Semiconductors 336
Power Semiconductor Power Loss 337
Conduction Losses of IGBT and Diode 337

Example: Boost IGBT Conduction Losses 339
Switching Losses of IGBT and Diode 339
Example: Switching Losses of IGBT Module 340
Total Semiconductor Power Loss and Junction Temperature 341
Example: Total IGBT Module Loss and Die Temperatures 342
Passive Components for Power Converters 342
Example: Inductor Sizing 342
Capacitor Sizing 343
Example: Capacitor Sizing 343
Interleaving 343
Example: Two-Phase Interleaved Boost Converter 345
References 346
Further Reading 346
Problems 346
Assignments 349
Appendix I 349
Appendix II: Buck-Boost Converter 349

12

Isolated DC-DC Converters 353
Introduction 353
Advantages of Isolated Power Converters 353
Power Converter Families 354

12.1
12.1.1
12.1.2

Contents

12.2
12.2.1
12.2.1.1
12.2.2
12.2.2.1
12.2.3
12.2.3.1
12.3
12.3.1
12.3.2
12.3.2.1
12.3.3
12.3.3.1
12.4
12.4.1
12.4.2
12.4.2.1
12.4.2.2
12.4.3
12.4.3.1
12.4.4

13

13.1
13.2
13.2.1
13.2.2

13.2.3
13.2.3.1
13.3
13.3.1
13.3.2
13.3.3
13.3.4
13.3.5
13.4
13.4.1
13.4.2
13.4.2.1

The Forward Converter 355
CCM Currents in Forward Converter 357
Example: Current Ratings in Medium-Power Forward Converter 360
CCM Voltages in Forward Converter 362
Example: Voltage Ratings in a Medium-Power Forward Converter 364
Sizing the Transformer 365
Example: AP of a Forward Converter Transformer 365
The Full-Bridge Converter 365
Operation of Hard-Switched Full-Bridge Converter 367
CCM Currents in Full-Bridge Converter 370
Example: Current Ratings in a Medium-Power Full-Bridge
Converter 373
CCM Voltages in the Full-Bridge Converter 376
Example: Voltage Ratings in a Full-Bridge Converter 376
Resonant Power Conversion 377
LCLC Series-Parallel Resonant Converter 377
Desirable Converter Characteristics for Inductive Charging 378

Basic Converter Operation 379
Design Considerations 381
Fundamental-Mode Analysis and Current-Source Operation 381
Example 384
Simulation 385
References 388
Further Reading 388
Problems 388
Assignments 390
Appendix I: RMS and Average Values of Ramp and Step Waveforms 390
Appendix II: Flyback Converter 391
Traction Drives and Three-Phase Inverters

392
Three-Phase Inverters 392
Modulation Schemes 393
Sinusoidal Modulation 395
Sinusoidal Modulation with Third Harmonic Addition 396
Overmodulation and Square Wave 398
Example: AC Voltages Available from DC Link 398
Sinusoidal Modulation 398
Modulation Index m 399
Inverter Currents 401
Switch, Diode, and Input Average Currents 401
Switch, Diode, DC Link, and Input Capacitor RMS Currents 403
Example: Inverter Currents 404
Inverter Power Loss 405
Conduction Loss of IGBT and Diode 405
Switching Loss of IGBT Module 405
Example: Power Losses of Power Semiconductor Module 405

xv


xvi

Contents

13.4.3
13.4.3.1
13.4.4

Total Semiconductor Power Loss and Junction Temperature 407
Example: Total IGBT Module Loss and Die Temperatures 408
Example: Regenerative Currents 408
References 409
Further Reading 409
Problems 410
Assignments 410

14

Battery Charging 412
Basic Requirements for Charging System 412
Charger Architectures 414
Grid Voltages, Frequencies, and Wiring 416
Charger Functions 418
Real Power, Apparent Power, and Power Factor 419
Charging Standards and Technologies 422
SAE J1772 422

VDE-AR-E 2623-2-2 425
CHAdeMo 425
Tesla 425
Wireless Charging 425
Inductive 425
Wireless 427
The Boost Converter for Power Factor Correction 427
The Boost PFC Power Stage 428
Sizing the Boost Inductor 430
Example: Sizing the Inductor 430
Average Currents in the Rectifier 431
Example: Input Rectifier Power Loss 432
Switch and Diode Average Currents 432
Switch, Diode, and Capacitor RMS Currents 434
Power Semiconductors for Charging 434
Example: Silicon MOSFET and SiC Diode Power Losses
Example: PFC Stage Losses 437
References 438
Further Reading 438
Problems 439
Assignments 440

14.1
14.2
14.3
14.4
14.4.1
14.5
14.5.1
14.5.2

14.5.3
14.5.4
14.5.5
14.5.5.1
14.5.5.2
14.6
14.6.1
14.6.2
14.6.2.1
14.6.3
14.6.3.1
14.6.4
14.6.5
14.6.6
14.6.6.1
14.6.6.2

15

15.1
15.1.1
15.2
15.2.1
15.2.2
15.2.3
15.2.4
15.3

Control of the Electric Drive

441
Introduction to Control 441
Feedback Controller Design Approach 442
Modeling the Electromechanical System 443
The Mechanical System 443
The PM DC Machine 446
The DC-DC Power Converter 447
The PI Controller 447
Designing Torque Loop Compensation 448

435


Contents

15.3.1
15.4
15.4.1
15.5
15.6

Example: Determining Compensator Gain Coefficients
for Torque Loop 449
Designing Speed Control Loop Compensation 449
Example: Determining Compensator Gain Coefficients
for Speed Loop 451
Acceleration of Battery Electric Vehicle (BEV) using PM DC Machine
Acceleration of BEV using WF DC Machine 452
References 455
Problems 455

Assignment and Sample MATLAB Codes 456
Part 4

Electromagnetism

451

459

16

Introduction to Electromagnetism, Ferromagnetism, and Electromechanical
Energy Conversion 461

16.1
16.1.1
16.1.1.1
16.1.1.2
16.1.1.3
16.1.1.4
16.1.1.5
16.2
16.2.1
16.2.2
16.2.2.1
16.2.2.2
16.3
16.3.1
16.3.2
16.3.2.1

16.3.2.2
16.3.3
16.3.3.1
16.3.3.2
16.3.3.3
16.3.4
16.3.4.1
16.3.5
16.3.5.1
16.3.5.2
16.3.5.3
16.3.5.4
16.3.5.5
16.3.6
16.3.6.1

Electromagnetism 462
Maxwell’s Equations 462
Ampere’s Circuital Law (Based on Ampere–Maxwell Law) 463
Right Hand Screw Rule: Direction of Magnetic Flux 464
Magnetic Flux Density Vector (B) 465
Magnetic Flux 465
Gauss’ Law for Magnetism 466
Ferromagnetism 467
Magnetism and Hysteresis 467
Hard and Soft Ferromagnetic Materials 470
Soft Ferromagnetic Materials 470
A Review of Commonly Used Soft Ferromagnetic Materials 471
Self-Inductance 473
Basic Inductor Operation 474

Inductor Equations 475
Example: A Gapped Inductor 477
Inductance Variation with Magnetization Curve 477
Reluctance 478
Example: A Gapless Inductor 480
Reluctance of Gapped Magnetic Structures 480
Example: Reluctances of Gapped Inductor 481
Energy Stored in Magnetic Field 481
Example: Inductor Energy Storage 482
Core Loss 482
Hysteresis Loss 482
Eddy Current Loss 483
Core Loss 484
Example: Core Loss 484
Core Loss Equivalent Parallel Resistance 484
Copper Loss 484
Copper Loss of Wire 485

xvii


xviii

Contents

16.3.6.2
16.3.6.3
16.3.6.4
16.3.7
16.3.8

16.4
16.4.1
16.4.2
16.4.3
16.4.4
16.4.5
16.4.5.1
16.4.5.2
16.4.6
16.4.6.1
16.5
16.5.1
16.5.2
16.5.3
16.5.3.1
16.5.3.2
16.5.3.3
16.5.3.4
16.5.4
16.6
16.6.1
16.7
16.7.1
16.7.1.1
16.7.2
16.7.3
16.7.4
16.7.5

Example: Copper Loss 485

Copper Loss of CC Core with Helical Winding 485
Example: MLT of Winding 486
Inductor Sizing using Area Product 487
High-Frequency Operation and Skin Depth 488
Hard Ferromagnetic Materials and Permanent Magnets 489
Example: Remanent Flux Density 490
Example: The Recoil Line 492
Example: Air Gap Flux Density due to a Permanent Magnet 494
Maximum Energy Product 494
Force due to Permanent Magnet 494
Example: Lifting Force of Magnet with no Gap 496
Example: Lifting Force of Magnet with Gap 496
Electromagnet 497
Example: Air Gap Flux Density due to Field Winding 497
The Transformer 498
Theory of Operation 498
Transformer Equivalent Circuit 500
Transformer Voltages and Currents 501
Exciting the Transformer with Sinusoidal Wave 503
Example: Induction Machine Magnetizing Current 504
Exciting the Transformer with a Square Wave Voltage 504
Example: High-Frequency Transformer 505
Sizing the Transformer using the Area-Product (AP) Method 505
The Capacitor 506
Sizing Polypropylene High-Voltage Capacitor 508
Electromechanical Energy Conversion 509
Ampere’s Force Law 509
Fleming’s Left Hand Rule 509
General Expression for Torque on Current-Carrying Coil 510
Torque, Flux Linkage, and Current 511

Faraday’s Law of Electromagnetic Induction 512
Lenz’s Law and Fleming’s Right Hand Rule 512
References 513
Further Reading 514
Further Viewing 515
Problems 515
Assignments 518
Reference Conversion Table 519
Index

521


xix

Preface

“The scientific man does not aim at an immediate result. He does not expect that
his advanced ideas will be readily taken up. His work is like that of the planter – for
the future. His duty is to lay the foundation for those who are to come, and point
the way.” Nikola Tesla (1856–1943).
“An inventor is simply a fellow who doesn’t take his education too seriously.”
Charles Kettering (1876–1958)
“A problem well stated is a problem half-solved.” Charles Kettering.
This book describes a technological evolution that has major implications around
the globe. The objective of this book is to provide the theory behind electric vehicles
and insight on the factors motivating the global adoption of these technologies. The
story told in the book is largely based on technologies originally developed in Detroit,
California, and Japan. However, these technologies are spreading rapidly around the
world, having been embraced by German, French, Chinese, and Korean and other global

manufacturers. While the car is changing, it is worth noting that the foundations of the
modern car are anything but new; vehicular technology and electrical machines are
products of the nineteenth century, while semiconductors, lithium-ion batteries, and
PEM fuel cells are products of the twentieth century. These technologies are significantly
impacting transportation in the early twenty-first century and becoming essential
components of the modern vehicle.
I had the privilege of working on the General Motors’ EV1 electric car program in
Southern California for ten years. The EV1 was the first electric car developed for mass
production in the modern era. I even met my wife, Mary, a mechanical engineer from
Detroit, when we worked together on the EV1 – we were both working on the new
wireless charging approach known as inductive coupling. I left the automotive world,
returning to Ireland to teach, and yet my teaching and research still revolve around automotive topics. The closest connection to automotive history here on the south coast of
Ireland is the ancestral home of the Ford family, from which William Ford fled to the
United States during the Great Irish Famine in 1847. His son, Henry Ford, was a
semi-literate Michigan farm boy, who grew up to revolutionize an industry and create
what we now call mass-market consumer capitalism.


xx

Preface

While it can be very useful for writing and teaching to be at a distance from the developing story, it is important not to be detached or isolated from such developments. My
co-author, Abas Goodarzi, is a former colleague who is living and working to deliver the
new technologies. Abas and I started work together at the General Motors’ Hughes
Aircraft subsidiary in Culver City, California, in October 1990. After directing the development of the EV1 electric powertrain, Abas pursued an electric vehicle start-up. After
working in a few more start-ups, Abas founded US Hybrid, where he remains CEO. US
Hybrid is a company specializing in delivering battery, hybrid, and fuel cell solutions for
heavy-duty transportation. Between us, we have been part of engineering teams which
have developed for mass production all of the technologies discussed in this book.

The modern automobile is a great topic for teaching because it is a consumer product
to which all students, family, and friends can relate and discuss. Also, it features engineering marvels such as energy storage, combustion engines, electric drives, power electronics, and more. The structure of this book is set up to explain how these technologies
interact in the vehicle as a whole and then becomes more technical as the book or a
particular chapter unfolds.
The book features problems and assignments of varying technical difficulty for university students. The reader can attempt them based on his or her level.
The car and electrical technology have a history rich with the contributions of many
prominent people. Hence, their quotations are often included at the start of a chapter.
They generally tie in with the story or underlying philosophies … and are often fun and
thought-provoking.


xxi

Acknowledgments
First, we’d like to thank all our colleagues in industry, government, and academia who
have provided us feedback, reviews, comments, suggestions, material, and criticism for
the book: Mohamed Alamgir, Peter Bardos, Ted Bohn, Amy Bueno, Tim Burress, Kevin
Cadogan, Paul Carosa, Gilsu Choi, Amgad Elgowainy, James Francfort, Mark Gibbons,
John Goodenough, Oliver Gross, John Hall, Silva Hiti, Gerard Hurley, Joe Kimmel, Tony
O’Gorman, Ray Radys, Wally Rippel, James Rohan, Brad Rutledge, Steve Schulz,
Matthew Shirk, Charlie Sullivan, and George Woody. Thank you to the all the staff at
Wiley, especially Michelle Dunckley, Adalfin Jayasingh, Aravind Kannankara and Athira
Menon, with a special mention for Peter Mitchell, who answered the question “do you
have any textbook which covers all of power electronics and machines and can help me
teach an electric vehicle course?” with “No, would you write one?”.
A word of thanks to all the supportive staff at University College Cork, especially
Michael Egan, and to the former students who have provided help and educated us at
times: David Cashman, Kevin Hartnett, Marcin Kacki, Brendan Lyons, Donal Murray,
and Marek Rylko; and especially to Brendan Barry, Kevin Davis, Diarmaid Hogan and
Robbie Ryan for final proofing and support. A special thank you to the undergraduate

and postgraduate students who patiently worked through the various drafts of the book.
We are grateful to the companies and various US agencies for providing us material
and would like to acknowledge their great work in the field: AC Propulsion, General
Motors, International Council on Clean Transportation (ICCT), Maxon Motors,
National Aeronautics and Space Administration (NASA), Jet Propulsion Laboratory
(JPL), and the Department of Energy laboratories: Argonne National Laboratory, Oak
Ridge National Laboratory, and Idaho National Laboratory.
Abas and I have been lucky to have been supervised in our postgraduate studies by
some seminal authors who have led the way in technical education: Ned Mohan of
the University of Minnesota, the late John M. D. Murphy of University College Cork,
and the late Richard Hoft of the University of Missouri (Columbia).
We wish to acknowledge our former colleagues at Hughes Power Control Systems, and
within the General Motors companies and beyond, for their contributions to the EV
industry, especially the first commercial battery electric car, featuring the first automotive IGBT traction inverter and an inductive charging infrastructure.
Finally, we thank our extended families and friends for their love, support, and endless
patience while we write books or start companies focused on electric vehicles. Mary and
Aryan are understanding spouses-Mary is an experienced EV engineer and Aryan is the
financial controller at US Hybrid. Thank you to Mary and the girls, Madi, Tasha, and
Saoirse, and to Aryan and the boys, Milad and Navid.


xxii

Textbook Structure and Suggested Teaching Curriculum
This is primarily an engineering textbook covering the automotive powertrain, energy
storage and energy conversion, power electronics, and electrical machines. A significant
additional focus is placed on the engineering design, the energy for transportation, and
the related environmental impacts. This textbook is an educational tool for practicing
engineers and others, such as transportation policy planners and regulators. The modern
automobile is used as the vehicle upon which to base the theory and applications, which

makes the book a useful educational reference for our industry colleagues, from chemists
to engineers. This material is also written to be of interest to the general reader, who may
have little or no interest in the power electronics and machines. Introductory science,
mathematics, and an inquiring mind suffice for some chapters. The general reader can read
the introduction to each of the chapters and move to the next as soon as the material gets
too advanced for him or her.
I teach the material across four years here at University College Cork. The material can
be taught across various years as outlined in Table I.
The first third of the book (Chapters 1 to 6), plus parts of Chapters 14 and 16, can be
taught to the general science or engineering student in the second or third year. It covers
the introductory automotive material using basic concepts from mechanical, electrical,
environmental, and electrochemical engineering. Chapter 14 on electrical charging and
Chapter 16 on electromagnetism can also be used as a general introduction to electrical
engineering.
The basics of electromagnetism, ferromagnetism and electromechanical energy conversion (Chapter 16) and dc machines (Chapter 7) are taught to second year (sophomore)
engineering students who have completed introductory electrical circuits and physics.
The third year (junior) students typically have covered ac circuit analysis, and so we
cover ac machines, such as the induction machine (Chapter 8) and the surface
permanent-magnet machine (Chapter 9). As the students typically have studied control
theory, we investigate the control of the speed and torque loops of the motor drive
(Chapter 15). Power electronics, featuring non-isolated buck and boost converters
(Chapter 11), is also introduced in the third year.
The final-year (senior) students then go on to cover the more advanced technologies of the interior-permanent-magnet machine (Chapter 10). Isolated power converters (Chapter 12), such as the full-bridge and resonant converters, inverters
(Chapter 13), and power-factor-corrected battery chargers (Chapter 14), are covered


Textbook Structure and Suggested Teaching Curriculum

xxiii

Table I Book content and related teaching.
Chapter

Topic

1

Vehicles
and
Energy
Sources

2
3
4
5
6
7

Electrical
Machines

General

Electromobility and the Environment

3rd

Y

Batteries

Y

Fuel Cells

Y

Conventional and Hybrid Powertrains

Y

Introduction to Traction Machines

Y
Y

8

Induction Machines

Y

9

Surface-Permanent-Magnet AC Machines

Y

10

Interior-Permanent-Magnet AC Machines

11

DC-DC Converters

12

Power
Electronics

4th/PG

Y

Vehicle Dynamics

The Brushed DC Machine

2nd

Y
Y

Isolated DC-DC Converters

Y

13

Traction Drives and Three-Phase Inverters

Y

14

Battery Charging

15

Control of the Electric Drive

16

Basics

Introduction to Electromagnetism,
Ferromagnetism, and Electromechanical
Energy Conversion

Y
Y
Y

in the power electronics section. This material can also be covered at the introductory
postgraduate level.
Various homework, simulation, and research exercises are presented throughout the
textbook. The reader is encouraged to attempt these exercises as part of the learning
experience.