Electric Vehicle Technology Explained

Table of Contents:
About the Author xiii Preface xv Acknowledgments xvii Abbreviations xix Symbols xxiii 1 Introduction 1 1.1 A Brief History 2 1.1.1 Early Days 2 1.1.2 The Middle of the Twentieth Century 7 1.1.3 Developments towards the End of the Twentieth Century and the Early Twenty-First Century 8 1.2 Electric Vehicles and the Environment 13 1.2.1 Energy Saving and Overall Reduction of Carbon Emissions 14 1.2.2 Reducing Local Pollution 15 1.2.3 Reducing Dependence on Oil 15 1.3 Usage Patterns for Electric Road Vehicles 15 Further Reading 17 2 Types of Electric Vehicles – EV Architecture 19 2.1 Battery Electric Vehicles 19 2.2 The IC Engine/Electric Hybrid Vehicle 19 2.3 Fuelled EVs 24 2.4 EVs using Supply Lines 25 2.5 EVs which use Flywheels or Supercapacitors 25 2.6 Solar-Powered Vehicles 26 2.7 Vehicles using Linear Motors 27 2.8 EVs for the Future 27 Further Reading 27 3 Batteries, Flywheels and Supercapacitors 29 3.1 Introduction 29 3.2 Battery Parameters 30 3.2.1 Cell and Battery Voltages 30 3.2.2 Charge (or Amphour) Capacity 31 3.2.3 Energy Stored 32 3.2.4 Specific Energy 33 3.2.5 Energy Density 33 3.2.6 Specific Power 34 3.2.7 Amphour (or Charge) Efficiency 34 3.2.8 Energy Efficiency 35 3.2.9 Self-discharge Rates 35 3.2.10 Battery Geometry 35 3.2.11 Battery Temperature, Heating and Cooling Needs 35 3.2.12 Battery Life and Number of Deep Cycles 35 3.3 Lead Acid Batteries 36 3.3.1 Lead Acid Battery Basics 36 3.3.2 Special Characteristics of Lead Acid Batteries 38 3.3.3 Battery Life and Maintenance 40 3.3.4 Battery Charging 40 3.3.5 Summary of Lead Acid Batteries 41 3.4 Nickel-Based Batteries 41 3.4.1 Introduction 41 3.4.2 Nickel Cadmium 41 3.4.3 Nickel Metal Hydride Batteries 44 3.5 Sodium-Based Batteries 46 3.5.1 Introduction 46 3.5.2 Sodium Sulfur Batteries 47 3.5.3 Sodium Metal Chloride (ZEBRA) Batteries 48 3.6 Lithium Batteries 50 3.6.1 Introduction 50 3.6.2 The Lithium Polymer Battery 50 3.6.3 The Lithium Ion Battery 51 3.7 Metal–Air Batteries 52 3.7.1 Introduction 52 3.7.2 The Aluminium–Air Battery 52 3.7.3 The Zinc–Air Battery 53 3.8 Supercapacitors and Flywheels 54 3.8.1 Supercapacitors 54 3.8.2 Flywheels 56 3.9 Battery Charging 59 3.9.1 Battery Chargers 59 3.9.2 Charge Equalisation 60 3.10 The Designer’s Choice of Battery 63 3.10.1 Introduction 63 3.10.2 Batteries which are Currently Available Commercially 63 3.11 Use of Batteries in Hybrid Vehicles 64 3.11.1 Introduction 64 3.11.2 IC/Battery Electric Hybrids 64 3.11.3 Battery/Battery Electric Hybrids 64 3.11.4 Combinations using Flywheels 65 3.11.5 Complex Hybrids 65 3.12 Battery Modelling 65 3.12.1 The Purpose of Battery Modelling 65 3.12.2 Battery Equivalent Circuit 66 3.12.3 Modelling Battery Capacity 68 3.12.4 Simulating a Battery at a Set Power 71 3.12.5 Calculating the Peukert Coefficient 75 3.12.6 Approximate Battery Sizing 76 3.13 In Conclusion 77 References 78 4 Electricity Supply 79 4.1 Normal Existing Domestic and Industrial Electricity Supply 79 4.2 Infrastructure Needed for Charging Electric Vehicles 80 4.3 Electricity Supply Rails 81 4.4 Inductive Power Transfer for Moving Vehicles 82 4.5 Battery Swapping 84 Further Reading 85 5 Fuel Cells 87 5.1 Fuel Cells – A Real Option? 87 5.2 Hydrogen Fuel Cells – Basic Principles 89 5.2.1 Electrode Reactions 89 5.2.2 Different Electrolytes 90 5.2.3 Fuel Cell Electrodes 93 5.3 Fuel Cell Thermodynamics – An Introduction 95 5.3.1 Fuel Cell Efficiency and Efficiency Limits 95 5.3.2 Efficiency and the Fuel Cell Voltage 98 5.3.3 Practical Fuel Cell Voltages 100 5.3.4 The Effect of Pressure and Gas Concentration 101 5.4 Connecting Cells in Series – The Bipolar Plate 102 5.5 Water Management in the PEMFC 106 5.5.1 Introduction to the Water Problem 106 5.5.2 The Electrolyte of a PEMFC 107 5.5.3 Keeping the PEM Hydrated 109 5.6 Thermal Management of the PEMFC 110 5.7 A Complete Fuel Cell System 111 5.8 Practical Efficiency of Fuel Cells 114 References 114 6 Hydrogen as a Fuel – Its Production and Storage 115 6.1 Introduction 115 6.2 Hydrogen as a Fuel 117 6.3 Fuel Reforming 118 6.3.1 Fuel Cell Requirements 118 6.3.2 Steam Reforming 118 6.3.3 Partial Oxidation and Autothermal Reforming 120 6.3.4 Further Fuel Processing – Carbon Monoxide Removal 121 6.3.5 Practical Fuel Processing for Mobile Applications 122 6.3.6 Energy Efficiency of Reforming 123 6.4 Energy Efficiency of Reforming 124 6.5 Hydrogen Storage I – Storage as Hydrogen 124 6.5.1 Introduction to the Problem 124 6.5.2 Safety 124 6.5.3 The Storage of Hydrogen as a Compressed Gas 125 6.5.4 Storage of Hydrogen as a Liquid 127 6.5.5 Reversible Metal Hydride Hydrogen Stores 129 6.5.6 Carbon Nanofibres 131 6.5.7 Storage Methods Compared 131 6.6 Hydrogen Storage II – Chemical Methods 132 6.6.1 Introduction 132 6.6.2 Methanol 133 6.6.3 Alkali Metal Hydrides 135 6.6.4 Sodium Borohydride 136 6.6.5 Ammonia 140 6.6.6 Storage Methods Compared 142 References 143 7 Electric Machines and their Controllers 145 7.1 The ‘Brushed’ DC Electric Motor 145 7.1.1 Operation of the Basic DC Motor 145 7.1.2 Torque Speed Characteristics 147 7.1.3 Controlling the Brushed DC Motor 151 7.1.4 Providing the Magnetic Field for DC Motors 152 7.1.5 DC Motor Efficiency 153 7.1.6 Motor Losses and Motor Size 156 7.1.7 Electric Motors as Brakes 156 7.2 DC Regulation and Voltage Conversion 159 7.2.1 Switching Devices 159 7.2.2 Step-Down or ‘Buck’ Regulators 161 7.2.3 Step-Up or ‘Boost’ Switching Regulator 162 7.2.4 Single-Phase Inverters 165 7.2.5 Three Phase 167 7.3 Brushless Electric Motors 169 7.3.1 Introduction 169 7.3.2 The Brushless DC Motor 169 7.3.3 Switched Reluctance Motors 173 7.3.4 The Induction Motor 177 7.4 Motor Cooling, Efficiency, Size and Mass 179 7.4.1 Improving Motor Efficiency 179 7.4.2 Motor Mass 181 7.5 Electric Machines for Hybrid Vehicles 182 7.6 Linear Motors 185 References 185 8 Electric Vehicle Modelling 187 8.1 Introduction 187 8.2 Tractive Effort 188 8.2.1 Introduction 188 8.2.2 Rolling Resistance Force 188 8.2.3 Aerodynamic Drag 189 8.2.4 Hill Climbing Force 189 8.2.5 Acceleration Force 189 8.2.6 Total Tractive Effort 191 8.3 Modelling Vehicle Acceleration 191 8.3.1 Acceleration Performance Parameters 191 8.3.2 Modelling the Acceleration of an Electric Scooter 193 8.3.3 Modelling the Acceleration of a Small Car 197 8.4 Modelling Electric Vehicle Range 198 8.4.1 Driving Cycles 198 8.4.2 Range Modelling of Battery Electric Vehicles 204 8.4.3 Constant Velocity Range Modelling 210 8.4.4 Other uses of Simulations 210 8.4.5 Range Modelling of Fuel Cell Vehicles 212 8.4.6 Range Modelling of Hybrid Electric Vehicles 215 8.5 Simulations – A Summary 215 References 216 9 Design Considerations 217 9.1 Introduction 217 9.2 Aerodynamic Considerations 217 9.2.1 Aerodynamics and Energy 217 9.2.2 Body/Chassis Aerodynamic Shape 220 9.3 Consideration of Rolling Resistance 222 9.4 Transmission Efficiency 223 9.5 Consideration of Vehicle Mass 227 9.6 Electric Vehicle Chassis and Body Design 229 9.6.1 Body/Chassis Requirements 229 9.6.2 Body/Chassis Layout 230 9.6.3 Body/Chassis Strength, Rigidity and Crash Resistance 231 9.6.4 Designing for Stability 234 9.6.5 Suspension for Electric Vehicles 234 9.6.6 Examples of Chassis used in Modern Battery and Hybrid Electric Vehicles 235 9.6.7 Chassis used in Modern Fuel Cell Electric Vehicles 235 9.7 General Issues in Design 237 9.7.1 Design Specifications 237 9.7.2 Software in the use of Electric Vehicle Design 237 10 Design of Ancillary Systems 239 10.1 Introduction 239 10.2 Heating and Cooling Systems 239 10.3 Design of the Controls 242 10.4 Power Steering 244 10.5 Choice of Tyres 245 10.6 Wing Mirrors, Aerials and Luggage Racks 245 10.7 Electric Vehicle Recharging and Refuelling Systems 245 11 Efficiencies and Carbon Release Comparison 247 11.1 Introduction 247 11.2 Definition of Efficiency 248 11.3 Carbon Dioxide Emission and Chemical Energy in Fuel 248 12 Electric Vehicles and the Environment 253 12.1 Introduction 253 12.2 Vehicle Pollution – The Effects 253 12.3 Vehicle Pollution in Context 256 12.4 The Role of Regulations and Lawmakers 256 Further Reading 258 13 Power Generation for Transport – Particularly for Zero Emissions 259 13.1 Introduction 259 13.2 Power Generation using Fossil Fuels 260 13.3 Alternative and Sustainable Energy 260 13.3.1 Solar Energy 260 13.3.2 Wind Energy 262 13.3.3 Hydroelectricity 263 13.3.4 Tidal Energy 264 13.3.5 Marine Currents 266 13.3.6 Wave Energy 266 13.3.7 Biomass Energy 267 13.3.8 Obtaining Energy from Waste 267 13.3.9 Geothermal Energy 267 13.4 Nuclear Energy 267 13.4.1 Nuclear Fission 267 13.4.2 Nuclear Fusion 268 13.5 In Conclusion 269 Further Reading 269 14 Recent Electric Vehicles 271 14.1 Introduction 271 14.2 Low-Speed Rechargeable Battery Vehicles 271 14.2.1 Electric Bicycles 271 14.2.2 Electric Mobility Aids 272 14.2.3 Low-Speed Vehicles 274 14.3 Battery-Powered Cars and Vans 274 14.3.1 Peugeot 106 and the Partner 274 14.3.2 The GM EV1 275 14.3.3 The Nissan Leaf 279 14.3.4 The Mitsubishi MiEV 279 14.4 Hybrid Vehicles 279 14.4.1 The Honda Insight 280 14.4.2 The Toyota Prius 281 14.4.3 The Chevrolet Volt 283 14.5 Fuel-Cell-Powered Bus 284 14.6 Conventional High-Speed Trains 286 14.6.1 Introduction 286 14.6.2 The Technology of High-Speed Trains 288 14.7 Conclusion 289 References 290 15 The Future of Electric Vehicles 291 15.1 Introduction 291 15.2 The Tesla S 291 15.3 The Honda FCX Clarity 292 15.4 Maglev Trains 292 15.5 Electric Road–Rail Systems 294 15.6 Conclusion 295 Further Reading 296 Appendices: MATLAB® Examples 297 Appendix 1: Performance Simulation of the GM EV1 297 Appendix 2: Importing and Creating Driving Cycles 298 Appendix 3: Simulating One Cycle 300 Appendix 4: Range Simulation of the GM EV1 Electric Car 302 Appendix 5: Electric Scooter Range Modelling 304 Appendix 6: Fuel Cell Range Simulation 306 Appendix 7: Motor Efficiency Plots 308 Index 311

About the Author :
Dr John Lowry, Acenti Designs Ltd., Swindon, UK Dr John Lowry is an engineer who has worked in industry and academia. He studied for his PhD at Queen Mary College, London University, and is a Fellow of the Institute of Mechanical Engineers, a Fellow of the Energy Institute and a Fellow of the Institute of Engineering and Technology. He was a Principal Lecturer at Oxford Brookes University from 1983 to 2001. He has acted as a consultant to numerous organisations in the UK and abroad and has been a consultant to the UN. Mr James Larminie, Oxford Brookes University, Oxford, UK James Larminie is a Principal Lecturer and is Director of Postgraduate Studies in the School of Technology at Oxford Brookes University. He co-authored the first edition of Electric Vehicle Technology Explained with Jon Lowry, which was published by John Wiley & Sons in 2003.