The why, what and how of the electric vehicle powertrain Empowers engineering professionals and students with the knowledge and skills required to engineer electric vehicle powertrain architectures, energy storage systems, power electronics converters and electric drives. The modern electric powertrain is relatively new for the automotive industry, and engineers are challenged with designing affordable, efficient and high-performance electric powertrains as the industry undergoes a technological evolution. Co-authored by two electric vehicle (EV) engineers with decades of experience designing and putting into production all of the powertrain technologies presented, this book provides readers with the hands-on knowledge, skills and expertise they need to rise to that challenge. This four-part practical guide provides a comprehensive review of battery, hybrid and fuel cell EV systems and the associated energy sources, power electronics, machines, and drives. Introduces and holistically integrates the key EV powertrain technologies. Provides a comprehensive overview of existing and emerging automotive solutions. Provides experience-based expertise for vehicular and powertrain system and sub-system level study, design, and optimization. Presents many examples of powertrain technologies from leading manufacturers. Discusses the dc traction machines of the Mars rovers, the ultimate EVs from NASA. Investigates the environmental motivating factors and impacts of electromobility. Presents a structured university teaching stream from introductory undergraduate to postgraduate. Includes real-world problems and assignments of use to design engineers, researchers, and students alike. Features a companion website with numerous references, problems, solutions, and practical assignments. Includes introductory material throughout the book for the general scientific reader. Contains essential reading for government regulators and policy makers. Electric Powertrain: Energy Systems, Power Electronics and Drives for Hybrid, Electric and Fuel Cell Vehicles is an important professional resource for practitioners and researchers in the battery, hybrid, and fuel cell EV transportation industry. The resource is a structured, holistic textbook for the teaching of the fundamental theories and applications of energy sources, power electronics, and electric machines and drives to engineering undergraduate and postgraduate students.

Table of Contents:
Preface xix Acknowledgments xxi Textbook Structure and Suggested Teaching Curriculum xxii About the Companion Web Site xxiv Part 1 Vehicles and Energy Sources 1 1 Electromobility and the Environment 3 1.1 A Brief History of the Electric Powertrain 4 1.1.1 Part I – The Birth of the Electric Car 4 1.1.2 Part II – The Resurgent Electric Powertrain 5 1.1.3 Part III – Success at Last for the Electric Powertrain 6 1.2 Energy Sources for Propulsion and Emissions 10 1.2.1 Carbon Emissions from Fuels 12 1.2.2 Greenhouse Gases and Pollutants 13 1.3 The Advent of Regulations 15 1.3.1 Regulatory Considerations and Emissions Trends 17 1.3.2 Heavy-Duty Vehicle Regulations 18 1.4 Drive Cycles 19 1.4.1 EPA Drive Cycles 19 1.5 BEV Fuel Consumption, Range, and mpge 24 1.6 Carbon Emissions for Conventional and Electric Powertrains 25 1.6.1 Well-to-Wheel and Cradle-to-Grave Emissions 27 1.6.2 Emissions due to the Electrical Grid 28 1.7 An Overview of Conventional, Battery, Hybrid, and Fuel Cell Electric Systems 29 1.7.1 Conventional IC Engine Vehicle 30 1.7.2 BEVs 30 1.7.3 HEVs 31 1.7.4 FCEV 33 1.7.5 A Comparison by Efficiency of Conventional, Hybrid, Battery, and Fuel Cell Vehicles 34 1.7.6 A Case Study Comparison of Conventional, Hybrid, Battery, and Fuel Cell Vehicles 35 1.8 A Comparison of Automotive and Other Transportation Technologies 36 References 37 Further Reading 38 Problems 38 Assignments 39 2 Vehicle Dynamics 40 2.1 Vehicle Load Forces 40 2.1.1 Basic Power, Energy, and Speed Relationships 41 2.1.2 Aerodynamic Drag 42 2.1.3 Rolling Resistance 45 2.1.4 Vehicle Road-Load Coefficients from EPA Coast-Down Testing 46 2.1.5 Battery Electric Vehicle Range at Constant Speed 49 2.1.6 Gradability 51 2.2 Vehicle Acceleration 52 2.2.1 Regenerative Braking of the Vehicle 54 2.2.2 Traction Motor Characteristics 54 2.2.3 Acceleration of the Vehicle 57 2.3 Simple Drive Cycle for Vehicle Comparisons 60 References 62 Further Reading 62 Problems 62 Sample MATLAB Code 63 Assignment: Modeling of a BEV 66 3 Batteries 68 3.1 Introduction to Batteries 68 3.1.1 Batteries Types and Battery Packs 68 3.1.2 Basic Battery Operation 73 3.1.3 Basic Electrochemistry 74 3.1.4 Units of Battery Energy Storage 76 3.1.5 Capacity Rate 77 3.1.6 Battery Parameters and Comparisons 79 3.2 Lifetime and Sizing Considerations 81 3.2.1 Examples of Battery Sizing 84 3.2.2 Battery Pack Discharge Curves and Aging 86 3.3 Battery Charging, Protection, and Management Systems 88 3.3.1 Battery Charging 88 3.3.2 Battery Failure and Protection 88 3.3.3 Battery Management System 89 3.4 Battery Models 90 3.4.1 A Simple Novel Curve Fit Model for BEV Batteries 92 3.4.2 Voltage, Current, Resistance, and Efficiency of Battery Pack 95 3.4.3 A Simple Curve-Fit Model for HEV Batteries 96 3.4.4 Charging 97 3.4.5 Determining the Cell/Pack Voltage for a Given Output\Input Power 99 3.4.6 Cell Energy and Discharge Rate 100 3.5 Example: The Fuel Economy of a BEV Vehicle with a Fixed Gear Ratio 102 References 105 Further Reading 106 Problems 106 Appendix: A Simplified Curve-Fit Model for BEV Batteries 108 4 Fuel Cells 111 4.1 Introduction to Fuel Cells 111 4.1.1 Fuel Cell Vehicle Emissions and Upstream Emissions 113 4.1.2 Hydrogen Safety Factors 113 4.2 Basic Operation 114 4.2.1 Fuel Cell Model and Cell Voltage 116 4.2.2 Power and Efficiency of Fuel Cell and Fuel Cell Power Plant System 118 4.2.3 Fuel Cell Characteristic Curves 119 4.3 Sizing the Fuel Cell Plant 120 4.3.1 Example: Sizing a Fuel Cell 121 4.3.2 Toyota Mirai 121 4.3.3 Balance of Plant 121 4.3.4 Boost DC-DC Converter 122 4.4 Fuel Cell Aging 122 4.5 Example: Sizing Fuel Cell System for Heavy Goods Tractor–Trailer Combination 124 4.6 Example: Fuel Economy of Fuel Cell Electric Vehicle 125 References 129 Problems 129 Assignments 130 5 Conventional and Hybrid Powertrains 131 5.1 Introduction to HEVs 131 5.2 Brake Specific Fuel Consumption 134 5.2.1 Example: Energy Consumption, Power Output, Efficiency, and BSFC 135 5.3 Comparative Examples of Conventional, Series, and Series-Parallel Hybrid Systems 138 5.3.1 Example: Fuel Economy of IC Engine Vehicle with Gasoline or Diesel Engine 138 5.3.2 Example: Fuel Economy of Series HEV 144 5.3.3 Example: Fuel Economy of Series-Parallel HEV 146 5.3.4 Summary of Comparisons 148 5.4 The Planetary Gears as a Power-Split Device 148 5.4.1 Powertrain of 2004 Toyota Prius 150 5.4.2 Example: CVT Operating in Electric Drive Mode (Vehicle Launch and Low Speeds) 151 5.4.3 Example: CVT Operating in Full-Power Mode 153 5.4.4 Example: CVT Operating in Cruising and Generating Mode 154 References 155 Problems 155 Assignments 156 Part 2 Electrical Machines 159 6 Introduction to Traction Machines 161 6.1 Propulsion Machine Overview 161 6.1.1 DC Machines 162 6.1.2 AC Machines 163 6.1.3 Comparison of Traction Machines 167 6.1.4 Case Study – Mars Rover Traction Motor 169 6.2 Machine Specifications 170 6.2.1 Four-Quadrant Operation 170 6.2.2 Rated Parameters 171 6.2.3 Rated Torque 172 6.2.4 Rated and Base Speeds 172 6.2.5 Rated Power 172 6.2.6 Peak Operation 173 6.2.7 Starting Torque 173 6.3 Characteristic Curves of a Machine 173 6.3.1 Constant-Torque Mode 173 6.3.2 Constant-Power Mode 174 6.3.3 Maximum-Speed Mode 174 6.3.4 Efficiency Maps 174 6.4 Conversion Factors of Machine Units 176 References 177 7 The Brushed DC Machine 178 7.1 DC Machine Structure 178 7.2 DC Machine Electrical Equivalent Circuit 180 7.3 DC Machine Circuit Equations 182 7.3.1 No-Load Spinning Loss 183 7.3.2 No-Load Speed 184 7.3.3 Maximum Power 184 7.3.4 Rated Conditions 184 7.4 Power, Losses, and Efficiency in the PM DC Machine 185 7.5 Machine Control using Power Electronics 186 7.5.1 Example: Motoring using a PM DC Machine 186 7.6 Machine Operating as a Motor or Generator in Forward or Reverse Modes 189 7.6.1 Example: Generating/Braking using a PM DC Machine 190 7.6.2 Example: Motoring in Reverse 191 7.7 Saturation and Armature Reaction 191 7.7.1 Example: Motoring using PM DC Machine and Machine Saturation 192 7.8 Using PM DC Machine for EV Powertrain 193 7.8.1 Example: Maximum Speeds using PM DC Machine 194 7.9 Using WF DC Machine for EV Powertrain 195 7.9.1 Example: Motoring using WF DC Machine 197 7.10 Case Study – Mars Rover Traction Machine 199 7.11 Thermal Characteristics of Machine 201 7.11.1 Example of Steady-State Temperature Rise 202 7.11.2 Transient Temperature Rise 203 7.11.3 Example of Transient Temperature Rise 203 References 204 Problems 204 8 Induction Machines 206 8.1 Stator Windings and the Spinning Magnetic Field 207 8.1.1 Stator Magnetic Flux Density 209 8.1.2 Space-Vector Current and the Rotating Magnetic Field 211 8.2 Induction Machine Rotor Voltage, Current, and Torque 216 8.2.1 Rotor Construction 216 8.2.2 Induction Machine Theory of Operation 216 8.3 Machine Model and Steady-State Operation 219 8.3.1 Power in Three-Phase Induction Machine 222 8.3.2 Torque in Three-Phase Induction Machine 223 8.3.3 Phasor Analysis of Induction Motor 225 8.3.4 Machine Operation When Supplied by Current Source 225 8.4 Variable-Speed Operation of Induction Machine 234 8.4.1 Constant Volts per hertz Operation 235 8.4.2 Variable-Speed Operation 235 8.5 Machine Test 240 8.5.1 DC Resistance Test 240 8.5.2 Locked-Rotor Test 240 8.5.3 No-Load Test 242 References 244 Further Reading 244 Problems 245 Sample MATLAB Code 246 9 Surface-Permanent-Magnet AC Machines 249 9.1 Basic Operation of SPM Machines 249 9.1.1 Back EMF of a Single Coil 249 9.1.2 Back EMF of Single Phase 250 9.1.3 SPM Machine Equations 253 9.2 Per-Phase Analysis of SPM Machine 255 9.2.1 Per-Phase Equivalent Circuit Model for SPM Machine 256 9.2.2 Phasor Analysis of SPM Machine 257 9.2.3 Machine Saturation 263 9.2.4 SPM Torque–Speed Characteristics 264 9.2.5 High-Speed Operation of SPM Machine above Rated Speed 266 9.2.6 Machine Characteristics for Field-Weakened Operation 270 References 272 Further Reading 273 Problems 273 MATLAB Code 274 10 Interior-Permanent-Magnet AC Machine 276 10.1 Machine Structure and Torque Equations 276 10.2 d- and q-Axis Inductances 278 10.2.1 Example: Estimating the d-axis and q-axis Inductances for 2004 Toyota Prius Motor 281 10.3 IPM Machine Test 281 10.3.1 No-Load Spin Test 282 10.3.2 DC Torque Test 282 10.4 Basic Theory and Low-Speed Operation 286 10.4.1 Example: Motoring at Rated Condition 287 10.4.2 Maximum Torque per Ampere (MTPA) 289 10.4.3 Maximum Torque per Volt (MTPV) or Maximum Torque per Flux (MTPF) 289 10.5 High-Speed Operation of IPM Machine 289 10.5.1 Example: Motoring at High Speed using IPM Machine 289 10.6 dq Modeling of Machines 291 10.6.1 Constant Current Transformation 292 10.6.2 Constant Power Transformation 294 References 295 Further Reading 295 Problems 296 Assignments 298 Part 3 Power Electronics 299 11 DC-DC Converters 301 11.1 Introduction 301 11.2 Power Conversion – Common and Basic Principles 304 11.2.1 The Basic Topologies 306 11.2.2 The Half-Bridge Buck-Boost Bidirectional Converter 307 11.3 The Buck or Step-Down Converter 307 11.3.1 Analysis of Voltage Gain of Buck Converter in CCM 309 11.3.2 BCM Operation of Buck Converter 317 11.3.3 DCM Operation of Buck Converter 319 11.4 The Boost or Step-up Converter 325 11.4.1 Analysis of Voltage Gain of Boost Converter in CCM 326 11.4.2 BCM Operation of Boost Converter 330 11.4.3 DCM Operation of Boost Converter 332 11.5 Power Semiconductors 336 11.5.1 Power Semiconductor Power Loss 337 11.5.2 Total Semiconductor Power Loss and Junction Temperature 341 11.6 Passive Components for Power Converters 342 11.6.1 Example: Inductor Sizing 342 11.6.2 Capacitor Sizing 343 11.7 Interleaving 343 11.7.1 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 Appendix III: Silicon Carbide Converters and Inverters 352 12 Isolated DC-DC Converters 353 12.1 Introduction 353 12.1.1 Advantages of Isolated Power Converters 353 12.1.2 Power Converter Families 354 12.2 The Forward Converter 355 12.2.1 CCM Currents in Forward Converter 357 12.2.2 CCM Voltages in Forward Converter 362 12.2.3 Sizing the Transformer 365 12.3 The Full-Bridge Converter 365 12.3.1 Operation of Hard-Switched Full-Bridge Converter 367 12.3.2 CCM Currents in Full-Bridge Converter 370 12.3.3 CCM Voltages in the Full-Bridge Converter 376 12.4 Resonant Power Conversion 377 12.4.1 LCLC Series-Parallel Resonant Converter 377 12.4.2 Desirable Converter Characteristics for Inductive Charging 378 12.4.3 Fundamental-Mode Analysis and Current-Source Operation 381 12.4.4 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 13 Traction Drives and Three-Phase Inverters 392 13.1 Three-Phase Inverters 392 13.2 Modulation Schemes 393 13.2.1 Sinusoidal Modulation 395 13.2.2 Sinusoidal Modulation with Third Harmonic Addition 396 13.2.3 Overmodulation and Square Wave 398 13.3 Sinusoidal Modulation 398 13.3.1 Modulation Index m 399 13.3.2 Inverter Currents 401 13.3.3 Switch, Diode, and Input Average Currents 401 13.3.4 Switch, Diode, DC Link, and Input Capacitor RMS Currents 403 13.3.5 Example: Inverter Currents 404 13.4 Inverter Power Loss 405 13.4.1 Conduction Loss of IGBT and Diode 405 13.4.2 Switching Loss of IGBT Module 405 13.4.3 Total Semiconductor Power Loss and Junction Temperature 407 13.4.4 Example: Regenerative Currents 408 References 409 Further Reading 409 Problems 410 Assignments 411 14 Battery Charging 412 14.1 Basic Requirements for Charging System 412 14.2 Charger Architectures 414 14.3 Grid Voltages, Frequencies, and Wiring 416 14.4 Charger Functions 418 14.4.1 Real Power, Apparent Power, and Power Factor 419 14.5 Charging Standards and Technologies 422 14.5.1 SAE J1772 422 14.5.2 VDE-AR-E 2623-2-2 425 14.5.3 CHAdeMo 425 14.5.4 Tesla 425 14.5.5 Wireless Charging 425 14.6 The Boost Converter for Power Factor Correction 427 14.6.1 The Boost PFC Power Stage 428 14.6.2 Sizing the Boost Inductor 430 14.6.3 Average Currents in the Rectifier 431 14.6.4 Switch and Diode Average Currents 432 14.6.5 Switch, Diode, and Capacitor RMS Currents 434 14.6.6 Power Semiconductors for Charging 434 References 438 Further Reading 438 Problems 439 Assignments 440 15 Control of the Electric Drive 441 15.1 Introduction to Control 441 15.1.1 Feedback Controller Design Approach 442 15.2 Modeling the Electromechanical System 443 15.2.1 The Mechanical System 443 15.2.2 The PM DC Machine 446 15.2.3 The DC-DC Power Converter 447 15.2.4 The PI Controller 447 15.3 Designing Torque Loop Compensation 448 15.3.1 Example: Determining Compensator Gain Coefficients for Torque Loop 449 15.4 Designing Speed Control Loop Compensation 449 15.4.1 Example: Determining Compensator Gain Coefficients for Speed Loop 451 15.5 Acceleration of Battery Electric Vehicle (BEV) using PM DC Machine 451 15.6 Acceleration of BEV using WF DC Machine 452 References 455 Problems 455 Assignment and Sample MATLAB Codes 456 Part 4 Electromagnetism 459 16 Introduction to Electromagnetism, Ferromagnetism, and Electromechanical Energy Conversion 461 16.1 Electromagnetism 462 16.1.1 Maxwell’s Equations 462 16.2 Ferromagnetism 467 16.2.1 Magnetism and Hysteresis 467 16.2.2 Hard and Soft Ferromagnetic Materials 470 16.3 Self-Inductance 473 16.3.1 Basic Inductor Operation 474 16.3.2 Inductor Equations 475 16.3.3 Reluctance 478 16.3.4 Energy Stored in Magnetic Field 481 16.3.5 Core Loss 482 16.3.6 Copper Loss 484 16.3.7 Inductor Sizing using Area Product 487 16.3.8 High-Frequency Operation and Skin Depth 488 16.4 Hard Ferromagnetic Materials and Permanent Magnets 489 16.4.1 Example: Remanent Flux Density 490 16.4.2 Example: The Recoil Line 492 16.4.3 Example: Air Gap Flux Density due to a Permanent Magnet 494 16.4.4 Maximum Energy Product 494 16.4.5 Force due to Permanent Magnet 494 16.4.6 Electromagnet 497 16.5 The Transformer 498 16.5.1 Theory of Operation 498 16.5.2 Transformer Equivalent Circuit 500 16.5.3 Transformer Voltages and Currents 501 16.5.4 Sizing the Transformer using the Area-Product (AP) Method 505 16.6 The Capacitor 506 16.6.1 Sizing Polypropylene High-Voltage Capacitor 508 16.7 Electromechanical Energy Conversion 509 16.7.1 Ampere’s Force Law 509 16.7.2 General Expression for Torque on Current-Carrying Coil 510 16.7.3 Torque, Flux Linkage, and Current 511 16.7.4 Faraday’s Law of Electromagnetic Induction 512 16.7.5 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