Electric Vehicle Technology Explained

Dr John Lowry, Acenti Designs Ltd., Swindon, UKDr 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, UKJames 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.

• About the Author xiiiPreface xvAcknowledgments xviiAbbreviations xixSymbols xxiii1 Introduction 11.1 A Brief History 21.1.1 Early Days 21.1.2 The Middle of the Twentieth Century 71.1.3 Developments towards the End of the Twentieth Century and the Early Twenty-First Century 81.2 Electric Vehicles and the Environment 131.2.1 Energy Saving and Overall Reduction of Carbon Emissions 141.2.2 Reducing Local Pollution 151.2.3 Reducing Dependence on Oil 151.3 Usage Patterns for Electric Road Vehicles 15Further Reading 172 Types of Electric Vehicles – EV Architecture 192.1 Battery Electric Vehicles 192.2 The IC Engine/Electric Hybrid Vehicle 192.3 Fuelled EVs 242.4 EVs using Supply Lines 252.5 EVs which use Flywheels or Supercapacitors 252.6 Solar-Powered Vehicles 262.7 Vehicles using Linear Motors 272.8 EVs for the Future 27Further Reading 273 Batteries, Flywheels and Supercapacitors 293.1 Introduction 293.2 Battery Parameters 303.2.1 Cell and Battery Voltages 303.2.2 Charge (or Amphour) Capacity 313.2.3 Energy Stored 323.2.4 Specific Energy 333.2.5 Energy Density 333.2.6 Specific Power 343.2.7 Amphour (or Charge) Efficiency 343.2.8 Energy Efficiency 353.2.9 Self-discharge Rates 353.2.10 Battery Geometry 353.2.11 Battery Temperature, Heating and Cooling Needs 353.2.12 Battery Life and Number of Deep Cycles 353.3 Lead Acid Batteries 363.3.1 Lead Acid Battery Basics 363.3.2 Special Characteristics of Lead Acid Batteries 383.3.3 Battery Life and Maintenance 403.3.4 Battery Charging 403.3.5 Summary of Lead Acid Batteries 413.4 Nickel-Based Batteries 413.4.1 Introduction 413.4.2 Nickel Cadmium 413.4.3 Nickel Metal Hydride Batteries 443.5 Sodium-Based Batteries 463.5.1 Introduction 463.5.2 Sodium Sulfur Batteries 473.5.3 Sodium Metal Chloride (ZEBRA) Batteries 483.6 Lithium Batteries 503.6.1 Introduction 503.6.2 The Lithium Polymer Battery 503.6.3 The Lithium Ion Battery 513.7 Metal–Air Batteries 523.7.1 Introduction 523.7.2 The Aluminium–Air Battery 523.7.3 The Zinc–Air Battery 533.8 Supercapacitors and Flywheels 543.8.1 Supercapacitors 543.8.2 Flywheels 563.9 Battery Charging 593.9.1 Battery Chargers 593.9.2 Charge Equalisation 603.10 The Designer’s Choice of Battery 633.10.1 Introduction 633.10.2 Batteries which are Currently Available Commercially 633.11 Use of Batteries in Hybrid Vehicles 643.11.1 Introduction 643.11.2 IC/Battery Electric Hybrids 643.11.3 Battery/Battery Electric Hybrids 643.11.4 Combinations using Flywheels 653.11.5 Complex Hybrids 653.12 Battery Modelling 653.12.1 The Purpose of Battery Modelling 653.12.2 Battery Equivalent Circuit 663.12.3 Modelling Battery Capacity 683.12.4 Simulating a Battery at a Set Power 713.12.5 Calculating the Peukert Coefficient 753.12.6 Approximate Battery Sizing 763.13 In Conclusion 77References 784 Electricity Supply 794.1 Normal Existing Domestic and Industrial Electricity Supply 794.2 Infrastructure Needed for Charging Electric Vehicles 804.3 Electricity Supply Rails 814.4 Inductive Power Transfer for Moving Vehicles 824.5 Battery Swapping 84Further Reading 855 Fuel Cells 875.1 Fuel Cells – A Real Option? 875.2 Hydrogen Fuel Cells – Basic Principles 895.2.1 Electrode Reactions 895.2.2 Different Electrolytes 905.2.3 Fuel Cell Electrodes 935.3 Fuel Cell Thermodynamics – An Introduction 955.3.1 Fuel Cell Efficiency and Efficiency Limits 955.3.2 Efficiency and the Fuel Cell Voltage 985.3.3 Practical Fuel Cell Voltages 1005.3.4 The Effect of Pressure and Gas Concentration 1015.4 Connecting Cells in Series – The Bipolar Plate 1025.5 Water Management in the PEMFC 1065.5.1 Introduction to the Water Problem 1065.5.2 The Electrolyte of a PEMFC 1075.5.3 Keeping the PEM Hydrated 1095.6 Thermal Management of the PEMFC 1105.7 A Complete Fuel Cell System 1115.8 Practical Efficiency of Fuel Cells 114References 1146 Hydrogen as a Fuel – Its Production and Storage 1156.1 Introduction 1156.2 Hydrogen as a Fuel 1176.3 Fuel Reforming 1186.3.1 Fuel Cell Requirements 1186.3.2 Steam Reforming 1186.3.3 Partial Oxidation and Autothermal Reforming 1206.3.4 Further Fuel Processing – Carbon Monoxide Removal 1216.3.5 Practical Fuel Processing for Mobile Applications 1226.3.6 Energy Efficiency of Reforming 1236.4 Energy Efficiency of Reforming 1246.5 Hydrogen Storage I – Storage as Hydrogen 1246.5.1 Introduction to the Problem 1246.5.2 Safety 1246.5.3 The Storage of Hydrogen as a Compressed Gas 1256.5.4 Storage of Hydrogen as a Liquid 1276.5.5 Reversible Metal Hydride Hydrogen Stores 1296.5.6 Carbon Nanofibres 1316.5.7 Storage Methods Compared 1316.6 Hydrogen Storage II – Chemical Methods 1326.6.1 Introduction 1326.6.2 Methanol 1336.6.3 Alkali Metal Hydrides 1356.6.4 Sodium Borohydride 1366.6.5 Ammonia 1406.6.6 Storage Methods Compared 142References 1437 Electric Machines and their Controllers 1457.1 The ‘Brushed’ DC Electric Motor 1457.1.1 Operation of the Basic DC Motor 1457.1.2 Torque Speed Characteristics 1477.1.3 Controlling the Brushed DC Motor 1517.1.4 Providing the Magnetic Field for DC Motors 1527.1.5 DC Motor Efficiency 1537.1.6 Motor Losses and Motor Size 1567.1.7 Electric Motors as Brakes 1567.2 DC Regulation and Voltage Conversion 1597.2.1 Switching Devices 1597.2.2 Step-Down or ‘Buck’ Regulators 1617.2.3 Step-Up or ‘Boost’ Switching Regulator 1627.2.4 Single-Phase Inverters 1657.2.5 Three Phase 1677.3 Brushless Electric Motors 1697.3.1 Introduction 1697.3.2 The Brushless DC Motor 1697.3.3 Switched Reluctance Motors 1737.3.4 The Induction Motor 1777.4 Motor Cooling, Efficiency, Size and Mass 1797.4.1 Improving Motor Efficiency 1797.4.2 Motor Mass 1817.5 Electric Machines for Hybrid Vehicles 1827.6 Linear Motors 185References 1858 Electric Vehicle Modelling 1878.1 Introduction 1878.2 Tractive Effort 1888.2.1 Introduction 1888.2.2 Rolling Resistance Force 1888.2.3 Aerodynamic Drag 1898.2.4 Hill Climbing Force 1898.2.5 Acceleration Force 1898.2.6 Total Tractive Effort 1918.3 Modelling Vehicle Acceleration 1918.3.1 Acceleration Performance Parameters 1918.3.2 Modelling the Acceleration of an Electric Scooter 1938.3.3 Modelling the Acceleration of a Small Car 1978.4 Modelling Electric Vehicle Range 1988.4.1 Driving Cycles 1988.4.2 Range Modelling of Battery Electric Vehicles 2048.4.3 Constant Velocity Range Modelling 2108.4.4 Other uses of Simulations 2108.4.5 Range Modelling of Fuel Cell Vehicles 2128.4.6 Range Modelling of Hybrid Electric Vehicles 2158.5 Simulations – A Summary 215References 2169 Design Considerations 2179.1 Introduction 2179.2 Aerodynamic Considerations 2179.2.1 Aerodynamics and Energy 2179.2.2 Body/Chassis Aerodynamic Shape 2209.3 Consideration of Rolling Resistance 2229.4 Transmission Efficiency 2239.5 Consideration of Vehicle Mass 2279.6 Electric Vehicle Chassis and Body Design 2299.6.1 Body/Chassis Requirements 2299.6.2 Body/Chassis Layout 2309.6.3 Body/Chassis Strength, Rigidity and Crash Resistance 2319.6.4 Designing for Stability 2349.6.5 Suspension for Electric Vehicles 2349.6.6 Examples of Chassis used in Modern Battery and Hybrid Electric Vehicles 2359.6.7 Chassis used in Modern Fuel Cell Electric Vehicles 2359.7 General Issues in Design 2379.7.1 Design Specifications 2379.7.2 Software in the use of Electric Vehicle Design 23710 Design of Ancillary Systems 23910.1 Introduction 23910.2 Heating and Cooling Systems 23910.3 Design of the Controls 24210.4 Power Steering 24410.5 Choice of Tyres 24510.6 Wing Mirrors, Aerials and Luggage Racks 24510.7 Electric Vehicle Recharging and Refuelling Systems 24511 Efficiencies and Carbon Release Comparison 24711.1 Introduction 24711.2 Definition of Efficiency 24811.3 Carbon Dioxide Emission and Chemical Energy in Fuel 24812 Electric Vehicles and the Environment 25312.1 Introduction 25312.2 Vehicle Pollution – The Effects 25312.3 Vehicle Pollution in Context 25612.4 The Role of Regulations and Lawmakers 256Further Reading 25813 Power Generation for Transport – Particularly for Zero Emissions 25913.1 Introduction 25913.2 Power Generation using Fossil Fuels 26013.3 Alternative and Sustainable Energy 26013.3.1 Solar Energy 26013.3.2 Wind Energy 26213.3.3 Hydroelectricity 26313.3.4 Tidal Energy 26413.3.5 Marine Currents 26613.3.6 Wave Energy 26613.3.7 Biomass Energy 26713.3.8 Obtaining Energy from Waste 26713.3.9 Geothermal Energy 26713.4 Nuclear Energy 26713.4.1 Nuclear Fission 26713.4.2 Nuclear Fusion 26813.5 In Conclusion 269Further Reading 26914 Recent Electric Vehicles 27114.1 Introduction 27114.2 Low-Speed Rechargeable Battery Vehicles 27114.2.1 Electric Bicycles 27114.2.2 Electric Mobility Aids 27214.2.3 Low-Speed Vehicles 27414.3 Battery-Powered Cars and Vans 27414.3.1 Peugeot 106 and the Partner 27414.3.2 The GM EV1 27514.3.3 The Nissan Leaf 27914.3.4 The Mitsubishi MiEV 27914.4 Hybrid Vehicles 27914.4.1 The Honda Insight 28014.4.2 The Toyota Prius 28114.4.3 The Chevrolet Volt 28314.5 Fuel-Cell-Powered Bus 28414.6 Conventional High-Speed Trains 28614.6.1 Introduction 28614.6.2 The Technology of High-Speed Trains 28814.7 Conclusion 289References 29015 The Future of Electric Vehicles 29115.1 Introduction 29115.2 The Tesla S 29115.3 The Honda FCX Clarity 29215.4 Maglev Trains 29215.5 Electric Road–Rail Systems 29415.6 Conclusion 295Further Reading 296Appendices: MATLAB® Examples 297Appendix 1: Performance Simulation of the GM EV1 297Appendix 2: Importing and Creating Driving Cycles 298Appendix 3: Simulating One Cycle 300Appendix 4: Range Simulation of the GM EV1 Electric Car 302Appendix 5: Electric Scooter Range Modelling 304Appendix 6: Fuel Cell Range Simulation 306Appendix 7: Motor Efficiency Plots 308Index 311