ELECTRIC VEHICLE TECHNOLOGY EXPLAINED

1 ELECTRIC VEHICLE . TECHNOLOGY . EXPLAINED . ELECTRIC VEHICLE . TECHNOLOGY . EXPLAINED . SECOND EDITION. James Larminie Oxford Brookes University, UK. John Lowry Consultant Engineer, Swindon, UK. A John Wiley & Sons, Ltd., Publication This edition rst published 2012. 2012 John Wiley & Sons Ltd Registered of ce John Wiley & Sons Ltd, The Atrium, Southern Gate, Chichester, West Sussex, PO19 8SQ, United Kingdom For details of our global editorial of ces, for customer services and for information about how to apply for permission to reuse the copyright material in this book please see our website at The right of the author to be identi ed as the author of this work has been asserted in accordance with the Copyright, Designs and Patents Act 1988. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording or otherwise, except as permitted by the UK Copyright, Designs and Patents Act 1988, without the prior permission of the publisher.

2 Wiley also publishes its books in a variety of electronic formats. Some content that appears in print may not be available in electronic books. Designations used by companies to distinguish their products are often claimed as trademarks. All brand names and product names used in this book are trade names, service marks, trademarks or registered trademarks of their respective owners. The publisher is not associated with any product or vendor mentioned in this book. This publication is designed to provide accurate and authoritative information in regard to the subject matter covered. It is sold on the understanding that the publisher is not engaged in rendering professional services. If professional advice or other expert assistance is required, the services of a competent professional should be sought.

3 matlab is a trademark of The MathWorks, Inc. and is used with permission. The MathWorks does not warrant the accuracy of the text or exercises in this book. This book's use or discussion of matlab software or related products does not constitute endorsement or sponsorship by The MathWorks of a particular pedagogical approach or particular use of the matlab software. Library of Congress Cataloging-in-Publication Data Larminie, James ELECTRIC VEHICLE TECHNOLOGY EXPLAINED / James Larminie, John Lowry.. Second Edition. pages cm Includes bibliographical references and index. ISBN 978-1-119-94273-3 (cloth). 1. ELECTRIC vehicles Technological innovations. 2. ELECTRIC vehicles . Design and construction. I. Lowry, John. II. Title. 2012. 93 dc23. 2012006649. A catalogue record for this book is available from the British Library.

4 Print ISBN: 9781119942733. Set in 10/12pt Times by Laserwords Private Limited, Chennai, India. Contents About the Author xiii Preface xv Acknowledgments xvii Abbreviations xix Symbols xxiii 1 Introduction 1. A Brief History 2. Early Days 2. The Middle of the Twentieth Century 7. Developments towards the End of the Twentieth Century and the Early Twenty-First Century 8. ELECTRIC Vehicles and the Environment 13. Energy Saving and Overall Reduction of Carbon Emissions 14. Reducing Local Pollution 15. Reducing Dependence on Oil 15. Usage Patterns for ELECTRIC Road Vehicles 15. Further Reading 17. 2 Types of ELECTRIC Vehicles EV Architecture 19. Battery ELECTRIC Vehicles 19. The IC Engine/ ELECTRIC Hybrid VEHICLE 19. Fuelled EVs 24. EVs using Supply Lines 25. EVs which use Flywheels or Supercapacitors 25.

5 Solar-Powered Vehicles 26. Vehicles using Linear Motors 27. EVs for the Future 27. Further Reading 27. 3 Batteries, Flywheels and Supercapacitors 29. Introduction 29. vi Contents Battery Parameters 30. Cell and Battery Voltages 30. Charge (or Amphour) Capacity 31. Energy Stored 32. Speci c Energy 33. Energy Density 33. Speci c Power 34. Amphour (or Charge) Ef ciency 34. Energy Ef ciency 35. Self-discharge Rates 35. Battery Geometry 35. Battery Temperature, Heating and Cooling Needs 35. Battery Life and Number of Deep Cycles 35. Lead Acid Batteries 36. Lead Acid Battery Basics 36. Special Characteristics of Lead Acid Batteries 38. Battery Life and Maintenance 40. Battery Charging 40. Summary of Lead Acid Batteries 41. Nickel-Based Batteries 41. Introduction 41. Nickel Cadmium 41.

6 Nickel Metal Hydride Batteries 44. Sodium-Based Batteries 46. Introduction 46. Sodium Sulfur Batteries 47. Sodium Metal Chloride (ZEBRA) Batteries 48. Lithium Batteries 50. Introduction 50. The Lithium Polymer Battery 50. The Lithium Ion Battery 51. Metal Air Batteries 52. Introduction 52. The Aluminium Air Battery 52. The Zinc Air Battery 53. Supercapacitors and Flywheels 54. Supercapacitors 54. Flywheels 56. Battery Charging 59. Battery Chargers 59. Charge Equalisation 60. The Designer's Choice of Battery 63. Introduction 63. Batteries which are Currently Available Commercially 63. Use of Batteries in Hybrid Vehicles 64. Introduction 64. Contents vii IC/Battery ELECTRIC Hybrids 64. Battery/Battery ELECTRIC Hybrids 64. Combinations using Flywheels 65. Complex Hybrids 65. Battery Modelling 65.

7 The Purpose of Battery Modelling 65. Battery Equivalent Circuit 66. Modelling Battery Capacity 68. Simulating a Battery at a Set Power 71. Calculating the Peukert Coef cient 75. Approximate Battery Sizing 76. In Conclusion 77. References 78. 4 Electricity Supply 79. Normal Existing Domestic and Industrial Electricity Supply 79. Infrastructure Needed for Charging ELECTRIC Vehicles 80. Electricity Supply Rails 81. Inductive Power Transfer for Moving Vehicles 82. Battery Swapping 84. Further Reading 85. 5 Fuel Cells 87. Fuel Cells A Real Option? 87. Hydrogen Fuel Cells Basic Principles 89. Electrode Reactions 89. Different Electrolytes 90. Fuel Cell Electrodes 93. Fuel Cell Thermodynamics An Introduction 95. Fuel Cell Ef ciency and Ef ciency Limits 95. Ef ciency and the Fuel Cell Voltage 98.

8 Practical Fuel Cell Voltages 100. The Effect of Pressure and Gas Concentration 101. Connecting Cells in Series The Bipolar Plate 102. Water Management in the PEMFC 106. Introduction to the Water Problem 106. The Electrolyte of a PEMFC 107. Keeping the PEM Hydrated 109. Thermal Management of the PEMFC 110. A Complete Fuel Cell System 111. Practical Ef ciency of Fuel Cells 114. References 114. 6 Hydrogen as a Fuel Its Production and Storage 115. Introduction 115. Hydrogen as a Fuel 117. viii Contents Fuel Reforming 118. Fuel Cell Requirements 118. Steam Reforming 118. Partial Oxidation and Autothermal Reforming 120. Further Fuel Processing Carbon Monoxide Removal 121. Practical Fuel Processing for Mobile Applications 122. Energy Ef ciency of Reforming 123. Energy Ef ciency of Reforming 124.

9 Hydrogen Storage I Storage as Hydrogen 124. Introduction to the Problem 124. Safety 124. The Storage of Hydrogen as a Compressed Gas 125. Storage of Hydrogen as a Liquid 127. Reversible Metal Hydride Hydrogen Stores 129. Carbon Nano bres 131. Storage Methods Compared 131. Hydrogen Storage II Chemical Methods 132. Introduction 132. Methanol 133. Alkali Metal Hydrides 135. Sodium Borohydride 136. Ammonia 140. Storage Methods Compared 142. References 143. 7 ELECTRIC Machines and their Controllers 145. The Brushed' DC ELECTRIC Motor 145. Operation of the Basic DC Motor 145. Torque Speed Characteristics 147. Controlling the Brushed DC Motor 151. Providing the Magnetic Field for DC Motors 152. DC Motor Ef ciency 153. Motor Losses and Motor Size 156. ELECTRIC Motors as Brakes 156. DC Regulation and Voltage Conversion 159.

10 Switching Devices 159. Step-Down or Buck' Regulators 161. Step-Up or Boost' Switching Regulator 162. Single-Phase Inverters 165. Three Phase 167. Brushless ELECTRIC Motors 169. Introduction 169. The Brushless DC Motor 169. Switched Reluctance Motors 173. The Induction Motor 177. Motor Cooling, Ef ciency, Size and Mass 179. Contents ix Improving Motor Ef ciency 179. Motor Mass 181. ELECTRIC Machines for Hybrid Vehicles 182. Linear Motors 185. References 185. 8 ELECTRIC VEHICLE Modelling 187. Introduction 187. Tractive Effort 188. Introduction 188. Rolling Resistance Force 188. Aerodynamic Drag 189. Hill Climbing Force 189. Acceleration Force 189. Total Tractive Effort 191. Modelling VEHICLE Acceleration 191. Acceleration Performance Parameters 191. Modelling the Acceleration of an ELECTRIC Scooter 193.