Small Electric Vehicles 1774694026, 9781774694022

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Small Electric Vehicles

SMALL ELECTRIC VEHICLES

Mukesh Pandey

ARCLER

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www.arclerpress.com

Small Electric Vehicles Mukesh Pandey

Arcler Press 224 Shoreacres Road Burlington, ON L7L 2H2 Canada www.arclerpress.com Email: [email protected]

e-book Edition 2023 ISBN: 978-1-77469-661-3 (e-book)

This book contains information obtained from highly regarded resources. Reprinted material sources are indicated and copyright remains with the original owners. Copyright for images and other graphics remains with the original owners as indicated. A Wide variety of references are listed. Reasonable efforts have been made to publish reliable data. Authors or Editors or Publishers are not responsible for the accuracy of the information in the published chapters or consequences of their use. The publisher assumes no responsibility for any damage or grievance to the persons or property arising out of the use of any materials, instructions, methods or thoughts in the book. The authors or editors and the publisher have attempted to trace the copyright holders of all material reproduced in this publication and apologize to copyright holders if permission has not been obtained. If any copyright holder has not been acknowledged, please write to us so we may rectify.

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© 2023 Arcler Press ISBN: 978-1-77469-402-2 (Hardcover)

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ABOUT THE AUTHOR

Prof. Dr. Mukesh Pandey is multi-skilled professional with around 30 years of rich exposure and versatile experience in Industries, Administration, Academics , Research domains and institution building. He received his B.E. from SATI Vidisha, M.Tech. from N.I.T. Bhopal and Ph.D. from RGPV, Bhopal. He played an instrumental role in the establishment of Rajiv Gandhi Technical University Bhopal, Madhya Pradesh since it’s inception in 1999. He served as Rector(Pro Vice Chancellor), Director SoEEM & Dean of Faculty of Energy Technology. He has looked after as Coordinator for establishing IIIT, Bhopal (under PPP Mode by MHRD). He held various administrative positions as Director (R&D), Coordinator of RGPV- NBA Nodal Centre, Dy. Registrar, Member of Engineering Accreditation Evaluation Committee [EAEC] and Moderation Committee of NBA(National Board of Accreditation). Professor Pandey works in the area of Renewable Energy and Environment having focus on Solar Thermal Energy and he has developed an Energy Technology Park at RGPV, Bhopal by making use of the renewable energy resources; Solar Roof Top Plant on University Building, Energy Systems, Solar Thin Film systems, Solar wind Hybrid System, , Bio-Diesel Reactor, CO2 Carbon Sequestration Unit, Dual Rotor Wind Turbine etc. Professor Pandey has an iconic track record of quality teaching, innovation and research he has been Principal Investigator of many Govt. Funded Projects by DST, MNRE, MPCST, AICTE etc including Principal Investigator of Innovative & Breakthrough Technology based 30KW CL-CSP SOLAR international R&D PROJECT (India-Japan Joint Venture Project) installed in RGPV campus. He has also facilitated as Reviewer for many national and international journals of repute and associated with many academic and research organizations at various levels. Over the past several years he has taught M.Tech. and Ph.D. Research Scholars in the areas of Energy, Environment, Direct Energy Conversion and Integrated Energy Systems and has been key-note speaker and resource person at several International and National Conferences and programmes.

TABLE OF CONTENTS

List of Figures.........................................................................................................xi List of Tables.........................................................................................................xv Glossary............................................................................................................. xvii List of Abbreviations............................................................................................ xxi Preface......................................................................................................... ....xxvii Chapter 1

Introduction to Electric Vehicles................................................................ 1 1.1. Introduction to Electric Vehicles........................................................... 2 1.2. Types of Electric Vehicles..................................................................... 5 1.3. Electric Vehicles Outperform Gas-Powered Cars.................................. 6 1.4. Application in Microgrid...................................................................... 9 1.5. Maximizing Ress Utilization.............................................................. 11 1.6. Comparison of the LCC of the Different EV Model............................. 13 1.7. Current Challenges and Problems in Electricity-Powered Vehicles..... 17 1.8. Energy Storage in Electric Vehicles..................................................... 18 1.9. System Configuration and Drive Train Structure................................. 19 1.10. Power Electronics............................................................................ 20 1.11. Advantages of Electric Vehicles........................................................ 20 1.12. Disadvantages of Electric Vehicles................................................... 22 1.13. Overview of Different Life Cycle Cost Frameworks for Electric Vehicles......................................................................... 24 1.14. Conclusion...................................................................................... 25 References................................................................................................ 26

Chapter 2

Battery, Flywheels, and Supercapacitors.................................................. 27 2.1. Introduction....................................................................................... 28 2.2. Batteries............................................................................................. 31

2.3. Battery Parameters............................................................................. 34 2.4. Use of Batteries in Hybrid Vehicles ................................................... 35 2.5. Battery Modeling............................................................................... 37 2.6. Supercapacitors................................................................................. 38 2.7. Flywheels.......................................................................................... 41 2.8. Existing Applications of Flywheel Battery........................................... 46 2.9. Energy Management of The EV........................................................... 47 2.10. Energy Storage Systems (ESSS) Requirements................................... 50 2.11. Conclusion...................................................................................... 53 References................................................................................................ 54 Chapter 3

Modeling and Simulation for Electric Vehicle Applications...................... 55 3.1. Introduction....................................................................................... 56 3.2. Simulation In The Loop of Electric Vehicles........................................ 57 3.3. Status and Trend of Power Semiconductor Module Packaging for Electric Vehicles......................................................................... 60 3.4. Power Semiconductor Module in HEV/EV.......................................... 61 3.5. Packaging Trend of HEV/EV Power Module........................................ 64 3.6. Passenger Exposure to Magnetic Fields in Electric Vehicles................ 67 3.7. Prevention Guidelines and Standards................................................. 69 3.8. State of the Art of Magnetic Gears (MGS), Their Design, and Characteristics With Respect to EV Application........................ 72 3.9. Switched Reluctance Drives (SRD) with Degraded Mode for Electric Vehicles......................................................................... 76 3.10. State of the Art................................................................................. 77 3.11. Load Leveling Utilizing Electric Vehicles and Their Used Batteries................................................................................. 79 3.12. Conclusion...................................................................................... 81 References................................................................................................ 82

Chapter 4

Electric Fuel............................................................................................. 85 4.1. Introduction....................................................................................... 86 4.2. How Fuel Cells (FCS) Work?.............................................................. 90 4.3. Parts of a Fuel Cell (FC)...................................................................... 91 4.4. Hydrogen As a Fuel........................................................................... 94 4.5. Facts About Hydrogen and Fuel Cells (FCS)....................................... 99 4.6. Realizing the Hydrogen Economy.................................................... 102 viii

4.7. Conclusion...................................................................................... 106 References.............................................................................................. 108 Chapter 5

Electric Vehicle Modeling and Design Consideration............................. 111 5.1. Introduction..................................................................................... 112 5.2. Vehicle Ownership and Annual Mileage Models.............................. 114 5.3. Modeling Annual Vehicle Use.......................................................... 116 5.4. Short-Period Models........................................................................ 118 5.5. Light Weighting Considerations Take Back Seat in Battery Electric Vehicle (BEV) Design........................................................ 120 5.6. Why EV Battery Design is So Difficult?............................................. 123 5.7. Overcoming Systemic Design Challenges for Electric Vehicles......... 129 5.8. Conclusion...................................................................................... 135 References.............................................................................................. 136

Chapter 6

New Applications of Electric Drives....................................................... 139 6.1. Introduction..................................................................................... 140 6.2. Electric Drive Application Background in Alternative Fuel Vehicles (AFVS)..................................................................... 140 6.3. Current Research Situation and New Challenges For Electric Drives in AFVS.................................................................. 142 6.4. Modeling and Control Strategy for Hybrid Electrical Vehicle............ 144 6.5. Fault Diagnosis of Switched Reluctance Motors (SRMS) in Electrified Vehicle Applications..................................................... 147 6.6. Principle of SRM.............................................................................. 148 6.7. Battery Management System (BMS) for Electric Drive Vehicles-Modeling, State Estimation and Balancing....................... 150 6.8. Battery Modeling............................................................................. 151 6.9. Electric Drives for Propulsion System of Transport Aircraft................ 155 6.10. Hybrid-Electric and Universally-Electric Propulsion System Architecture....................................................................... 156 6.11. Enabling Technologies for Electric Drive Application to Transport Aircraft....................................................................... 158 6.12. Electric-Driven Zonal Hydraulics in Non-Road Mobile Machinery (NRMM).......................................................... 160 6.13. Variable Frequency Drive Applications in HVAC Systems............... 164 6.14. VFD............................................................................................... 165

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6.15. VFD Applications........................................................................... 166 6.16. Conclusion.................................................................................... 167 References.............................................................................................. 168 Chapter 7

Future of Electric Vehicles..................................................................... 169 7.1. Making Batteries Better.................................................................... 170 7.2. The Future is Electric........................................................................ 175 7.3. Plugging Into the Future: The Electric Vehicle Market Outlook......... 177 7.4. The Future of Mobility is at Our Doorstep........................................ 180 7.5. Considering the Future: Electric Vehicle Market Projections............. 184 7.6. What is the Future of Electric Cars in India?..................................... 188 7.7. Conclusion...................................................................................... 197 References.............................................................................................. 198

Chapter 8

New Trends in Electric Powertrains....................................................... 199 8.1. Introduction..................................................................................... 200 8.2. Model-Based System Design for Electric Vehicle Conversion........... 201 8.3. Motion Dynamics Control of Electric Vehicles................................. 204 8.4. Some Important Trends in Battery Technology Development............ 205 8.5. Adaptive Control for Estimating Insulation Resistance of High Voltage Battery System In Electric Vehicles........................ 208 8.6. The Application of X-by-Wire Technology in Electric Vehicle in Braking and Steering..................................................... 210 8.7. Some Important Trend in Engine of Electric Powertrain.................... 215 8.8. Conclusion...................................................................................... 227 References.............................................................................................. 228

Index...................................................................................................... 229

x

LIST OF FIGURES Figure 1.1. Fuel cell electric vehicle at ITM power hydrogen station Figure 1.2. Toyota Prius: A plug-in hybrid electric vehicle Figure 1.3. Picture depicting an electric vehicle power station Figure 1.4. Microgrid with RES BESS grid-connected to each other Figure 1.5. Comparison of CC of the different electric vehicle models Figure 1.6. Current challenges and problems in electricity-powered vehicles Figure 1.7. Energy storage in electric vehicles Figure 1.8. System configuration and drive train structure Figure 1.9. Advantages of electric vehicles Figure 1.10. Disadvantages of electric vehicles Figure 2.1. Power density versus energy density at room temperature Figure 2.2. Energy efficiency versus energy density at room temperature Figure 2.3. Simple equivalent circuit model of a battery. This battery is composed of six cells Figure 2.4. Use of batteries in hybrid vehicles Figure 2.5. Battery modeling Figure 2.6. Supercapacitors in EV Figure 2.7. EV specific aluminum lightweight flywheel Figure 2.8. Existing application of flywheel battery Figure 3.1. Modeling and simulation for electric vehicle applications Figure 3.2. Simulation in the loop of electric vehicles Figure 3.3. The schematic of power-train system in the EV Figure 3.4. Inverter cost breakdown Figure 3.5. Packaging trend of HEV/EV power module Figure 3.6. Passenger exposure to magnetic fields in electric vehicles Figure 3.7. Prevention guidelines and standards Figure 3.8. Losses in the propulsion system Figure 3.9. Load leveling utilizing electric vehicles and their used batteries

Figure 4.1. A picture depicting an internal combustion engine (IC Engine) Figure 4.2. An illustration of a fuel cell Figure 4.3. An illustration of membrane electrode assembly Figure 4.4. An illustration of PEM electrolysis Figure 4.5. Toyota hydrogen fuel cell at the 2014 New York international auto show Figure 4.6. Hydrogen as a fuel Figure 4.7. An illustration of hydrogen molecule Figure 4.8. An electric vehicle driven by hydrogen fuel Figure 4.9. Commercial hydrogen fuel station Figure 4.10. Realizing the hydrogen economy Figure 5.1. Electric vehicle modeling and design consideration Figure 5.2. Vehicle ownership and annual mileage models Figure 5.3. Modeling annual vehicle use Figure 5.4. Short-period models Figure 5.5. Lightweight EV design Figure 5.6. Why EV battery design is so difficult? Figure 5.7. Charging consideration in EV Figure 5.8. Overcoming systemic design challenges for electric vehicles Figure 5.9. Performance and lifetime Figure 5.10. Electrical architecture in EV Figure 6.1. Electric drive application background in alternative fuel vehicles Figure 6.2. Modeling and control strategy for hybrid electrical vehicle Figure 6.3. SRM driver system Figure 6.4. 8/6-pole SRM Figure 6.5. Power converter Figure 6.6. Review of battery equivalent circuit models Figure 6.7. Electric drives for propulsion system of transport aircraft Figure 6.8. Electric-driven zonal hydraulics in non-road mobile machinery Figure 6.9. Schematics of (a) conventional NRMM; (b) hybrid NRMM with secondary power source DDH with a conventional tank; and (c) DDH without a tank Figure 6.10. Variable frequency drive applications in HVAC systems Figure 7.1. An electric car charging station Figure 7.2. Developing a network: The right power in the right place Figure 7.3. Picture depicting an electric car charging at station xii

Figure 7.4. The future of mobility is at the doorstep Figure 7.5. Achieving the future EV targets Figure 7.6. An illustration of plug-in hybrid electric vehicle Figure 7.7. Electric cars have zero-emission compared to conventional fuel cars Figure 7.8. Auto manufacturers can help bridge gaps Figure 7.9. Leveraging tech to reduce range anxiety Figure 8.1. Illustration of electric powertrain Figure 8.2. Model-based design process for EV conversion Figure 8.3. Motion dynamics control of electric vehicles Figure 8.4. Adaptive control for estimating insulation resistance Figure 8.5. Gas turbine engines of automobile Figure 8.6. Stirling engines of automobile Figure 8.7. Hybrid energy storage system for electric vehicles

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LIST OF TABLES Table 3.1. Data for electronic-driven vehicles vs. motor-driven vehicles Table 3.2. Some of the best-selling electric cars, in series production: Propulsion’s characteristics and approximate cost/unit Table 3.3. Comparison of traction chain weights for different configurations containing classic Table 3.4. Worldwide production of Nd-Fe-B at the 2013-year level

GLOSSARY

A Accumulator – a person or thing that accumulates something. Anode – is an electrode through which the conventional current enters a polarized electrical device. B Battery – A battery is a device consisting of one or more electrochemical cells with external connections for powering electrical devices such as flashlights, mobile phones, and electric cars. C Carbonate – a carbonate is a salt of carbonic acid, characterized by the presence of the carbonate ion, a polyatomic ion with the formula of CO²⁻₃. Catalyst – is a substance that can be added to a reaction to increase the reaction rate without getting consumed in the process. Cathode – is the electrode from which a conventional current left a polarized electrical device. Chauffeurs – a person employed to drive a private or hired car. Circuit – An electronic circuit is composed of individual electronic components, such as resistors, transistors, capacitors, inductors, and diodes, connected by conductive wires or traces through which electric current can flow. Clutch – is the mechanical device which transfers the rotational power from the engine to the wheels in any manual vehicle. Combustion Engines – is a heat engine in which the combustion of a fuel occurs with an oxidizer in a combustion chamber that is an integral part of the working fluid flow circuit. Commercialization – the process of managing or running something principally for financial gain. Composites – a composite material is a material which is produced from two or more constituent materials. Compressed Air – It is air kept under a pressure that is greater than atmospheric pressure. Conceivable – capable of being imagined or grasped mentally. Conductivity – is the measure of the ease at which an electric charge or heat can pass through a material.

Contingent – subject to chance. Corrosion – is a natural process that converts a refined metal into a more chemically stable form such as oxide, hydroxide, or sulfide. D Descriptively – Serving or seeking to describe. Disaggregate – separate (something) into its component parts. Discrete – individually separate and distinct. Dispersed – distribute or spread over a wide area. E Elastomers – An elastomer is a polymer with viscoelasticity and with weak intermolecular forces, generally low Young’s modulus and high failure strain compared with other materials. Electrodes – an electrode is an electrical conductor used to make contact with a nonmetallic part of a circuit. Electrolyte – is a substance that produces an electrically conducting solution when dissolved in a polar solvent, such as water. Electromagnet – An electromagnet is a type of magnet in which the magnetic field is produced by an electric current. Electromagnets usually consist of wire wound into a coil. Endogenous – having an internal cause or origin. Endothermic – an endothermic process is any process with an increase in the enthalpy H of the system. Equilibrium – is the state in which both reactants and products are present in concentrations which have no further tendency to change with time, so that there is no observable change in the properties of the system. Exogenous – having an external cause or origin. Expectancy – the state of thinking or hoping that something, especially something good, will happen. F Farad – the SI unit of electrical capacitance, equal to the capacitance of a capacitor in which one coulomb of charge causes a potential difference of one volt. Fluctuation – an irregular rising and falling in number or amount; a variation. Flywheels – It is a mechanical device specifically designed to use the conservation of angular momentum to efficiently store rotational energy, a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. G Garnered – gather or collect (something, especially information or approval).

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H Humidifiers – a humidifier is a device, primarily an electrical appliance, that increases humidity in a single room or an entire building. Hybrid Vehicle – A hybrid vehicle is one that uses two or more distinct types of power, such as submarines that use diesel when surfaced and batteries when submerged. Hybridization – the process of an animal or plant breeding with an individual of another species or variety. Hydraulic Springs – It is the most common type of gas springs, where the speed is controlled by a piston and dampened at the end of the stroke by oil. K Kinematics – It is a subfield of physics, developed in classical mechanics, that describes the motion of points, bodies, and systems of bodies without considering the forces that cause them to move. M Microchamber – The microchamber is a stainless-steel pot with 40 ml volume, 4.5 cm diameter and two operation modes. In the cell mode, the whole test piece is tested, with all surfaces. Microgrid – is a self-sufficient energy system that serves a discrete geographic footprint, such as a college campus, hospital complex, business center, or neighborhood. P Perplexed – completely baffled; very puzzled. Piqued – feel irritated or resentful. Polymer – polymer is a substance or material consisting of very large molecules, or macromolecules, composed of many repeating subunits. Power – It is the amount of energy transferred or converted per unit time. Powertrain – In a motor vehicle, the powertrain consists of the source of propulsion and the drivetrain system which transfers this energy into forward movement of the vehicle. Propelled – drive or push something forwards. R Rebates – a partial refund to someone who has paid too much for tax, rent, or a utility. Regenerative – tending to or characterized by regeneration. Reluctance – The property of a magnetic circuit of opposing the passage of magnetic flux lines, equal to the ratio of the magnetomotive force to the magnetic flux. Renewable Energy – It is useful energy that is collected from renewable resources, which are naturally replenished on a human timescale, including carbon neutral sources like sunlight, wind, rain, tides, waves, and geothermal heat.

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S Shaft – a long, narrow part or section forming the handle of a tool or club, the body of a spear or arrow, or similar. Simulation – a simulation is the imitation of the operation of a real-world process or system over time. Spinel – a hard glassy mineral occurring as octahedral crystals of variable color and consisting chiefly of magnesium and aluminum oxides. T Thyristor – A thyristor is a solid-state semiconductor device with four layers of alternating P- and N-type materials. Topology – is the mathematical study of the properties that are preserved through deformations, twisting, and stretching of objects. Torque – It is the measure of the force that can cause an object to rotate about an axis. Force is what causes an object to accelerate in linear kinematics. Traction – is a set of mechanisms for straightening broken bones or relieving pressure on the spine and skeletal system. Transmission – sending something out or passing something on from one person, place, or thing to another. U Ubiquity – the fact of appearing everywhere or of being very common. Ultracapacitors – It is electrical energy storage device that can store a large amount of electrical charge. Unlike the resistor, which dissipates energy in the form of heat, the ideal capacitor does not lose its energy. V Veracity – conformity to facts; accuracy.

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LIST OF ABBREVIATIONS

A Ampere ABS

Anti-Lock Braking System

AC Alternating Current ACC

Adaptive Cruise Control

ADVISOR

Advanced Vehicle Simulator

AEVs All-Electric Vehicles AFCs

Alkaline Fuel Cells

AFD Adjustable-Frequency Drive AFVs Alternative Fuel Vehicles ASD Adjustable-Speed Drive ASSP

Application-Specific Standard Products

AWD All-Wheel Drive BESS

Battery Energy Storage System

BEV Battery Electric Vehicle BMS

Battery Management System

BNEF

Bloomberg New Energy Finance

BWB Blended Wing Body CAFÉ

Corporate Average Fuel Economy

CAV

Commercial, Construction, and Agricultural Vehicles

CIT CarMaker Interface Toolbox CO2 Carbon Dioxide CPO

Catalytic Partial Oxidation

CVT

Continuously Variable Transmission

DC Direct Current DCA Dynamic Charge Acceptance DC-IM

DC Insulation Monitoring

DCM DC Motors DCT Dual Clutch Transmission

DDH

Direct Driven Hydraulics

DDP

Dynamic Discharge Performance Test

DDVAV

Dual Duct Variable Air Volume System

DEWA

Dubai Electricity and Water Authority

DICI

Direct Injection Compression Ignition

DMFCs

Direct Methanol Fuel Cells

DOD Depth-of-Discharge DOE

Department of Energy

DSM

Demand Side Management

DVA Direct Variable Access ECU

Electronic Control Unit

EDLC

Double-Layer Electrical Capacitors

EDVs Electric-Drive Vehicles EFC

Energy Flow Controller

EHA Electrohydraulic Actuator EIS

Electrochemical Impedance Spectroscopy

EMC Electromagnetic Compatibility EMDS

Electric Motor Driven System

EMFs Electromagnetic Fields EMI Electromagnetic Interference EMR Electromagnetic Radiation EMs Electric Motors EMS

Energy Management System

EPS

Electric Power Steering

ERA European Research Agency ESP

Electronic Stability Program

ESSs

Energy Storage Systems

ETC Electronic Throttle Control EV Electric Vehicle FC Fuel Cell FCEVs

Fuel Cell Electric Vehicles

FWD Free-Wheeling Diode GC Ground Capacitance GDLs

Gas Diffusion Layers xxii

GHGs Greenhouse Gases HEV Hybrid Electric Vehicle HIL hardware‐in‐the‐loop HPPC

Hybrid Pulse Power Characterization

HSS High-Strength Steel HTS High-Temperature Superconducting HV High Voltage HVAC Heating Ventilation and Air-Conditioning IARC

International Agency for Research on Cancer

IC Integrated Circuit ICE

Internal Combustion Engine

ICNIRP

International Commission on Non‐Ionizing Radiation

Protection IEEE

Institute of Electrical and Electronics Engineers

IGBT

Insulated Gate Bipolar Transistor

IM Induction Machines LDVs Low Voltage Directives LFP

Lithium Iron Phosphate

Li-Ion Lithium-Ion LMIs

Linear Matrix Inequalities

LTO Lithium Titanate Oxide MCFCs

Molten Carbonate Fuel Cells

MCFM

McKinsey Center for Future Mobility

MDCEV

Multiple Discrete-Continuous Extreme Value

MEA Membrane Electrode Assemblies MG Magnetic Gear MILP

Mixed Integer Linear Programming

MOSFETs

Metal Oxide Semiconductor Field Effect Transistor

NCA

Nickel Cobalt Aluminum Oxide

NEMMP

National Electric Mobility Mission Plan

NiMH

Nickel Metal Hydride

NMC

Nickel Manganese Cobalt Oxide

NMPC

Nonlinear Model Predictive Control

NRMM

Non-road Mobile Machinery xxiii

OEM

Original Equipment Manufacturers

PAFCs

Phosphoric Acid Fuel Cells

PDM

Power Distribution Management

PEM

Polymer Electrolyte Membrane

PEMFC

Proton Exchange Membrane Fuel Cell

PGM

Platinum Group Metal

PHEV

Plug-in Hybrid Electric Vehicles

PMAD

Power Management and Distribution System

PMSM Drives

Permanent Magnet Synchronous Motor Drive

PMSM

Permanent Magnet Synchronous Machines

PSM

Power Supply Management

PTFE Poly Tetra Fluoro-Ethylene PVs Photovoltaics PWM Drive

Pulse-Width-Modulated Drive

RESS

Rechargeable Energy Storage System

RESs

Renewable Energy Sources

RMPC

Robust Model Predictive Control

RSM

Reluctance Synchronous Machines

S/P Serial/Parallel SAT Supply Air Temperature SBD

Schottky Barrier Diode

SBS

Sensotronic Brake System

SMDP

Semi-Markov Decision Process

SOC

State of Charge

SOFCs

Solid Oxide Fuel Cells

SRD

Switched Reluctance Drives

SRIA

Strategic Research and Innovation Agenda

SRM

Switched Reluctance Motor

SRMs

Switched Reluctance Machines

SRS

Steering Reduction System

TACOM Tank-Automotive Command TFL

Transport for London

TPLS

Transient Liquid Phase Sintering

TTA Time-Triggered Architecture xxiv

TTP Time-Triggered Protocol UDDS

Urban Dynamometer Driving Schedule

ULEV

Ultra Low Emission Vehicle

UPSs

Uninterruptible Power Supplies

USABC

U.S. Advanced Battery Consortium

V2G Vehicle-to-Grid VAV Variable Air Volume VFDs

Variable Frequency Drives

VNH

Vibration, Noise, and Harshness

VVVF

Variable Voltage Variable Frequency

WHO

World Health Organization

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PREFACE Electric vehicles are the vehicles that either entirely powered on electric power or partially powered on electric power. Electric vehicles are comparatively cost-effective, the reason being electric vehicles have fewer moving parts for maintaining and also, these EVs are very environmentally friendly as there is no emission of toxic gases and use little or no fossil fuels (such as petrol, gasoline, or diesel). This book takes the readers through various aspects and various types of electric vehicles. This book sheds light on the several characteristics of electric vehicles, battery, flywheels, capacitors, electric fuel, electric vehicle modeling and design considerations. The 1st chapter stresses on the basic overview of the electric vehicles so that the readers are clear about the various types of electric vehicles and their applications that form the utmost basics in the field. This chapter will also emphasize the application of EVs in microgrid, comparison of the LCC of different EV models, and current challenges and problems in EV. The 2nd chapter takes the readers through the concepts of battery, flywheels, and supercapacitors. This chapter will provide highlights on the use of batteries in hybrid vehicles, the modeling of batteries, existing applications of flywheel batteries, energy management of the EV. Then, the 3rd chapter explains the modeling and simulation for electric vehicle applications. It also explains the simulation in the loop of electric vehicles. This chapter also sheds light on the status and trends of power semiconductor module packaging for electric vehicles. The 4th chapter introduces the readers to the electric fuel and its application in the EVs. This chapter also explains the working of fuel cells (FCs), various parts of fuel cells, the significance of hydrogen fuel cells, and various facts about hydrogen and its fuel cells that have been used in EVs. The 5th chapter throws light on the concept of electric vehicle modeling and its design consideration. This chapter contains different approaches in the context of vehicle ownership and annual mileage models, modeling annual vehicle use, short-period models, and light-weighting consideration in electric vehicles. The 6th chapter takes the readers through the various applications of electric drives. The readers are then told about the principle of SRM, battery modeling, battery management system (BMS) for electric drives, and electric-driven zonal hydraulics drive application to transport aircraft.

The 7th chapter explains the future of electricity-powered vehicles. This chapter also emphasize how electric cars will be considered in India and the future of EVs in India. The last chapter of this book sheds light on the new trends in electric powertrains. This chapter also mentions about the model-based design for electric vehicles, adaptive controls for estimating insulation resistance, the application of x-by-wire technology in EV in braking and steering. This book has been designed to suit the knowledge and pursuit of the researcher and scholars and to empower them with various aspects, application, future, and trends of electric vehicles, so that they are updated with the information. I hope that the readers find the book explanatory and insightful and that this book is referred by the scholars across various fields.

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CHAPTER

1

INTRODUCTION TO ELECTRIC VEHICLES

CONTENTS 1.1. Introduction to Electric Vehicles........................................................... 2 1.2. Types of Electric Vehicles..................................................................... 5 1.3. Electric Vehicles Outperform Gas-Powered Cars.................................. 6 1.4. Application in Microgrid...................................................................... 9 1.5. Maximizing Ress Utilization.............................................................. 11 1.6. Comparison of the LCC of the Different EV Model............................. 13 1.7. Current Challenges and Problems in Electricity-Powered Vehicles..... 17 1.8. Energy Storage in Electric Vehicles..................................................... 18 1.9. System Configuration and Drive Train Structure................................. 19 1.10. Power Electronics............................................................................ 20 1.11. Advantages of Electric Vehicles........................................................ 20 1.12. Disadvantages of Electric Vehicles................................................... 22 1.13. Overview of Different Life Cycle Cost Frameworks for Electric Vehicles......................................................................... 24 1.14. Conclusion...................................................................................... 25 References................................................................................................ 26

2

Small Electric Vehicles

The chapter of introduction to electric vehicles explains the basic concept and ideology behind the electric drives or electricity-driven vehicles. This chapter also explains the various types of the electric vehicles such as battery electric vehicles (BEVs), all-electric vehicles, and plug-in hybrid electric vehicles (PHEVs). This chapter addresses the electric outperform gas-powered cars such as key differences, battery charges for electric vehicles, and efficiencyaware electric vehicles. This chapter also explains the application of electric vehicles in microgrid. This chapter also mentions how to maximize the utilization of renewable energy source. This chapter explains the comparison of the LCC of the different electric vehicle model. This chapter provides highlights on the challenges and problems in EV in a present interval of time. This chapter also explains the concept of electric storage in electric vehicles, system configuration and drive train structure, and power electronics of the electric-based vehicles. This chapter sheds light on the advantages or disadvantages of the electric vehicles.

1.1. INTRODUCTION TO ELECTRIC VEHICLES The needs of different drivers can be accommodated in the plug-in electric vehicles (EVs or electric cars) currently available in the market in a manner similar to the conventional vehicles which had varied kinds of technology available to them. An electric power source which is off-board can be used by the drivers to plug in and charge their EV, and this is one of the major features of these vehicles. Herein they become different from the hybrid electric vehicles (HEVs) where the vehicle cannot be plugged in and a battery power supplements the internal combustion engine (ICE). EVs are basically of two types: Plug-in hybrid electric vehicles (PHEVs) and all-electric vehicles (AEVs). Further, fuel cell electric vehicles (FCEVs) and battery electric vehicles (BEVs) are included in the category of AEVs. Energy is lost during braking, and some of this energy is used to generate electricity by regenerative braking, which along with charging from the electric grid is used to generate both these kinds of vehicles.

Introduction to Electric Vehicles

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Depending upon the driving habits and individual needs a specific kind of vehicle may suit the individual. As per one’s requirements, the kind of PHEVs and BEVs best suited can be opted for. Only electricity is used to run AEVs. Even though some of the luxury models have a range of up to 250 miles, most AEVs have a range of 80 to 100 miles. Depending upon the kind of battery and charger used, with Level 1 charging, it can take anything from 30 minutes to an entire day to charge up a depleted battery. It may be a better choice to use a plug-in electric vehicle or a PHEV where this range does not seem to be sufficient. When the battery gets depleted for shorter ranges (6 to 40 miles) the PHEV switches over from running on electricity to a gasoline-run ICE. PHEVs give the flexibility to the drivers to switch over to gasoline after fueling their vehicles as per requirement and as often as possible use electricity. Compared to the conventional vehicle’s electricity-powered vehicles (from the grid) help to reduce tailpipe emissions, reduce fuel costs and it cuts the consumption of petroleum. PHEVs work like HEVs when the driving distances exceed the all-electric range so that fewer emissions are produced and at the same time the fuel consumption too is lesser than that for conventional vehicles which are similar. At other times like when air condition is being used or whilst rapid acceleration is being done, as per the model in use, the vehicle may also be powered by the internal combustion. Instead of gasoline, other alternative fuels too may be used in PHEVs like biofuels or hydrogen in a fuel cell (FC). Due to their lower dependency on oil and fewer emissions, electric vehicles (EVs) and more specifically the plug-in vehicles are gaining popularity. By 2022 over the globe the number of EVs is likely to be over 35 million, and by 2024, their sales per year would, in all probability reach 2.4 million in U.S. alone (Figure 1.1).

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Figure 1.1. Fuel cell electric vehicle at ITM power hydrogen station. Source: Image by Wikimedia commons.

All the same transformer and branch congestion is likely to result from the large impact on the power grid that shall be a consequence of the large amount of demand in charging these vehicles once they penetrate deeply. Associating the charging infrastructure with local power generation like the renewable energy sources (RESs) can be an effective solution to bring about a mitigation of this impact. For instance, Nissan Leaf charging is provided with solar power by SunPower and solar power system is provided to Tesla EVs by SolarCity. There is a degree of fun, speed, and efficiency associated with plugin electric vehicles (EVs). At the same time, they are cheaper and easier to maintain. Simple plugging can help to ‘refuel’ the vehicle saving about $1.50 per gallon of gas in equivalent terms. The carbon emissions reduce and whilst increasing our energy independence EVs help in contributing towards a healthier air. The best time to take advantage of the incentives being provided on the purchase of EVs is now as it reduces the price of these vehicles.

The carbon emissions reduce and whilst increasing our energy independence EVs help in contributing towards a healthier air. The best time

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to take advantage of the incentives being provided on the purchase of EVs is now as it reduces the price of these vehicles.

1.2. TYPES OF ELECTRIC VEHICLES Electric vehicles that can be plugged income in a series of sizes and shapes. Electricity powered options have a large variety, and these are very efficient, like neighborhood electric vehicles, bicycles assisted by electricity, and motorcycles. There are two basic designs of EVs for the Vermonters’ trucks and passenger cars.

1.2.1. Battery Electric Vehicles (BEVs) The typical architecture of BEVs consisting of mainly three parts namely: rechargeable battery, controller, and electric motor. Rechargeable battery is utilized by the electric motor as a source of energy for the generation of propulsion. The electric motor drives the vehicle so that it can move either forward or backward, and the power for this is supplied through the management by a two-quadrant controller. A four-quadrant controller is the one that can also support regenerative braking. The inverter is yet another important part of a BEV. DC power or the power that the battery stores is converted into AC (alternating current) power by an inverter as ACs motors that are cheaper and have simple schemes equip most of the electric motors (EMs).

1.2.2. All Electric Vehicles (AEVs) Examples of some of the AEVs in Vermont include Hyundai Kona, Tesla Model 3, Chevrolet Bolt, Nissan Leaf and BMW i3. For the lovers of the electric vehicle who have a pioneering spirit and short commuting two-car households, these are the best option. On the coldest Vermont days, as opposed to the official ratings given by the manufacturers, the range shall be much lower. Whilst buying the vehicle, certain considerations should be factored in like for instance, in frigid conditions, the range shall be closer to 125 miles as opposed to the official range of 250 miles for an AEV. It has become quite easy to make a switch nowadays with a number of all-electric models offering a range of over 200 miles.

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1.2.3. Plug-In Hybrid Electric Vehicles (PHEVs) Some of the examples of PHEVs are the Ford Fusion Energi, Chevrolet Volt and Toyota Prius Prime. The gasoline engine help to extend the range of these vehicles whenever the battery runs low even though their overall range is less than that for the AEVs run on battery power (Figure 1.2).

Figure 1.2. Toyota Prius: A plug-in hybrid electric vehicle. Source: Image by Wikimedia Commons.

1.3. ELECTRIC VEHICLES OUTPERFORM GAS-POWERED CARS Certain features that are seen mainly in the luxury segment of the vehicles like Bluetooth, heated steering wheel, navigation, and heated seats as well as electric panels can often be seen in the electric vehicles. As the weight of the batteries is distributed, in addition to providing all the other features as can be seen in most of the other vehicles, a tremendous amount of traction is provided by electric vehicles. As per a number of owners, in comparison to the AWD vehicles that they may have owned in the past, the suitability of EVs is far higher in the Vermont snow.

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1.3.1. The Key Difference Torque is generated from the start in electric motor vehicles, whereas fuel is burnt in the ICE so that heat can be generated to create propulsion. In a vehicle powered by gasoline, a delay is caused when the pedal is touched, whereas in an electric car when the accelerator is pressed, no delay is caused. The competing of the electricity-powered vehicles in the top levels of racing is quite evident in the Formula E racing series.

1.3.2. Battery Chargers for Electric Vehicles Due to a life span that is longer, higher energy density, and lesser influence on the environment, Li-ion battery is used by most PEVs to store energy. All the same, charging Li-ion batteries is not a simple matter as it requires current output of the charger and delicate control of voltage. If this is not done, the battery may get damaged due to current fluctuation and a large voltage. The development of PEVs can be accelerated tremendously through battery charger design that is advanced. As of now, off-board, and onboard are the categorizations used for PEVs battery chargers. Owing to its cost limits, space, and weight, the power level of the on-board charger is generally restricted. On the other hand, the off-board charger is not bound by these limits. Furthermore, the distinction of the PEVs battery chargers can also be done on the basis of whether the power flow directions supported by them are bidirectional where the power can be drawn from the grid as well injected back into it or if it is unidirectional where the power is charged only to the battery from the charger. Most of the times, in comparison to the bidirectional chargers, the hardware requirements are lower, and the interconnections are simpler in a unidirectional charger. Currently, single-phase chargers which are used commonly for charging at Level 1 and Level 2 equip most of the PEVs (Figure 1.3).

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Figure 1.3. Picture depicting an electric vehicle power station. Source: Image by Wikimedia Commons.

All the same, based on the assumption that the technique of vehicleto-grid (V2G) has been realized and there is an availability of bidirectional chargers, a lot of research has been done. It is envisioned in the technique of V2G that power can be injected back to the grid by electric vehicles.

1.3.3. Efficiency-Aware Electric Vehicles The fossil fuel consumption can go down tremendously through the use of renewable energy efficiently. Many benefits can accrue from this, like a reduction in the contamination of air and for the customers, and enhanced cost performance. To a certain level, this objective can be achieved through the interaction of RESs and EVs. This section reviews the research efforts based on three objectives namely: • Optimizing energy dispatch; • Optimizing the management of energy; and • Maximizing RESs utilization. Problems like convex programming and linear programming can be formulated as optimization problems for the efficiency-aware objectives. Evolutionary algorithm (like genetic algorithm) and optimization tools (like IBM CPLEX) are some of the solutions that exist as of now for these problems that have been formulated.

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1.4. APPLICATION IN MICROGRID In a microgrid with respect to the efficiency-aware objective, efforts have been made to research the interacting in EVs with RESs. An optimal scheduling was developed by well-known researcher Tushar for joint control electricity consumption of EVs and appliances. Minimizing electricity generation from the external grid and utilizing the electricity generated by RESs optimally is the objective. Only wind power, a central controller, EVs, PV solar power and home appliances have been considered by the microgrid. Either a mode interacting with the grid or a self-sustained mode can be utilized to operate it. The formulation of the scheduling problem is done as a mixed-integer linear programming problem (MILP). EVs can be considered as energy storage during the hours of renewable power generation; additional electricity shall be provided by the EVs during the period when the demand for electricity is high. The prediction for the generation of solar power and wind power during the next 24 hours is done through the Markov chain state transition probability. As per the varying requirements, the differentiation of the home appliances is done for instance, whereas a flexible scheduling may be required for some, the others may require a stricter scheduling. A Poisson process is presumed to be followed by the arrival in microgrid of the EVs. There can be a random distribution of EVs with varying energy demands so that the duration of charging them can be randomly at home. The IBM CPLEX MLP solver is used to solve the formulated model that includes discrete and continuous decision variables. In variation to the findings of researcher named, the wind power has been considered as the single resource to interact with EVs by well-known researcher named Wu and optimizing of the wind power’s utilization efficiency in the microgrid is the aim here. For the interaction of EVs with wind power, three energy dispatching methods that are coordinated have been proposed by them based on the flexibility in control of the EV’s discharging and charging behaviors. Individual vehicle’s distribution of SOC and the volatility of power generation are the factors covered by their model. Interruptible dispatching, valley searching dispatching and variable-rate dispatching are the three approaches. The statistic model from the ICE vehicles of the families has

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been used to portray the driving patterns of EVs by arrival time, departure time, and the distance driven. Normal distributions have been used to model the arrival and departure times. Algorithm normal distribution is used to model the driving distance. EV’s residual energy that is available is represented by using SOC. Results from the simulation show that the matching performance can be improved efficiently through the three methods that have been proposed. The microgrid model considered by Strnad et al. integrates the PV solar plants, thermal units, a diesel power generator, EVs charging station and BESS (battery energy storage system) (Figure 1.4).

Figure 1.4. Microgrid with RES BESS grid-connected to each other. Source: Image by Wikimedia commons.

The aim is that when electricity is generated through energy and when BESS or EVs are charged through the electricity generated by the thermal units and PV solar plants, the utilization is maximum. This way there can be an alleviation of the impact caused by the charging of EVs on the microgrid. The cost of production affects the schedule for the generation of diesel power generator. Specifically speaking, only when the cost of the electricity purchased from the grid is higher than the cost for generation of the same

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amount of power from a diesel generator, the latter is started when there is a shortage of power supply faced by the microgrid. For their case study power system of the Faculty of Electrical Engineering and Computing in Zagreb has been utilized by the authors. With an interval of 15 min a simulation covering one summer and one winter workday has been provided by them. The amount of electricity required in this scenario, even when a slow charging rate is used 8 working hours suffice to charge the EVs and the RES can easily supply this amount of electricity. For the maximum utilization of RESs in the microgrid charging policies have been proposed by well-known researcher Zhu. The semiMarkov decision process (SMDP) has been used for the formulation of the optimization process wherein RESs states, EVs number and battery states have been considered. Only one PV solar panel was considered by them in the solar panel; however they claimed that other sources of renewable energy like hydro and wind energy too could equally be applied with this model. To model the solar radiation, the continuous Markov chain has been used by the authors Tushar and to model the battery states, the linear method has been used, and the leftover store of energy in the battery is obtained by using this. The transition probabilities are obtained by using the Poisson process’ decomposition property since they take EVs departure and arrival rate as Poisson distribution. The current PV solar panel system, number of EVs charged by BESS, the number of EVs charged by the PV solar panel and current remaining battery energy, all comprise the system. Further, the probabilities of state transition characterize the system dynamics. The SMDP model is used to solve the linear programming technology.

1.5. MAXIMIZING RESS UTILIZATION According to the researcher named as Gottwalt, the RESs utilization can be maximized through the EVs charging which is regarded as kind of a flexible load. The residential household demand is satisfied simultaneously with coordination of the charging behavior of the EVs by using an aggregator. The empirical driving profiles are used to model only the behavior of the EVs that have full-time employees as owners.

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A German dataset is the basis for deriving their household demand. Conventional generator and renewable energy were the source for the electricity. Only when the energy demanded by the households and for charging the EVs is in excess of the amount that is available from RESs does the conventional generator get initiated. The generation from conventional means shall be minimized when the demand of EVs is coordinated well with the generation that is available from RESs. This has been formulated as a problem of mixed-integer programming by Gottwalt et al. An assumption has been made by them that knowledge of the traveling behavior of EVs, future RESs and the household load for one week is available. Fast operating uncoordinated charging has been first evaluated by them so that the benefits of coordinated charging can be demonstrated by them. Thereafter for a period of 52 weeks, the coordinated method is simulated and evaluated in detail. IBM ILOG CPLEX 12.4 is used to solve the problem of the proposed mixed-integer programming. The electricity demand of the residents can be met through this work as one of the means to meet it. On the other hand, maximizing the RESs utilization through the demand from charging EVs has been the focus of the researcher named as Mets. To coordinate the supply of wind energy and demand of EVs charging, a demand-side management (DSM) algorithm was adopted by them. As a result, there can be the maximum utilization of the renewable energy. They ensure through their method that the energy consumption is matched with the supply of energy for a certain period. A coordinator and EVs owners comprise the objective of the power system. The demand can be changed by the EVs owners so that the order can be maintained. An imbalance in the cost shall be inevitable where the demand is not met by the supply. Hence, there is a transformation of the original problem of the maximization of the RESs into a problem of minimization of the imbalance cost. This is formulated as a problem of convex optimization. The method of dual decomposition is adopted to solve this. The Lagrange multipliers method is applied to move the constraints of the objective function. A case study was carried out by the authors for four weeks so that the proposed method could be evaluated. The results of the simulation showed that in the most ideal scenario, 73% of the demand can be satisfied; however, in the real-world scenario, this is impractical. At the same time, demand for

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68% of the energy can be supplied through the usage of their distributed algorithm. A demand of about 40% can be supplied in the business scenario of the usual kind.

1.6. COMPARISON OF THE LCC OF THE DIFFERENT EV MODEL The LCC of EV’s different model that has been obtained from literature. Depending upon the type of EVs the LCC also varies. Factors like the type of EVs, the economic factors that are prevailing, the model being used, and the government policies in existence within the countries where the study is being conducted affect the variation in the LCC. Based on the LCC analysis, the competitiveness of EVs in China was reported by well-known researcher named as Diao. It was revealed by the authors that factors like government policies and promotions as well as the impact of the incentive policies that were non-economic were the basis for EVs competitiveness in China. During the study period, China had certain incentives in place like exemption of the EVs from restrictions on driving and purchase restrictions. Based on the driving restrictions and cost of purchase which were intangible as they existed in China Diao modeled the BYD e6 BEV and BALK EV 200 BEV that was reported by them. Compared to the 1.80 million US dollars that were obtained for the BALK EV 200 BEV brand, much higher LCC was obtained for the BYD e6 BEV brand namely to the tune of 2.63 million US dollars. It was concluded by the authors that in comparison to the conventional vehicles, the tangible costs of the EVs were not competitively economical. Based on the battery size, the LCC of three models of EVs was investigated by a researcher named as Hao in a similar study. EV 100 was used to code the EV that had the lowest battery whereas EV300 was used to code the one with the largest battery size. It was seen that depending on the size of the battery, there was a variation in the LCC where the lowest LCC was seen for the EV100 and the highest for EV 300. It was concluded by the authors that during the study period in China in terms of cost, the EVs were not competitive enough. For the two EV’s models, the LCC was lower vis-à-vis the hydrogen EVs.

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An analysis was conducted by a well-known researcher named as Wong of the various models that are available in Singapore. It was revealed in the result that the types of EVs affected the LCC. In comparison to all the other EVs, the highest cost of LCC was found to be for the EV of the Mitsubishi brand. The EVs prototype reported by Kara, Propfe, and Hao gave a low LCC which was at par or competitive enough with the Wong et al. reported hybrid EVs. The existing policies of the government in China could have been the cause for the LCC on the EVs reported there (Figure 1.5).

Figure 1.5. Comparison of CC of the different electric vehicle models.

The increased demand in China of the EVs could be due to the large number of policies in China with respect to the EVs as identified by researcher named Zhang. The national finance policy jointly issued in 2013 by the Ministry of Industry and information technology, the Ministry of Science and Technology and the Ministry of Finance is one such policy. It was believed that through the process of commercialization, the cost of the EVs would reduce drastically due to this policy. Furthermore, for various consumers of EV, charging poles became more accessible as a result of the national infrastructure promotion policy for EVs being operational, which promoted construction planning, charging pricing policies and interface standardization. Wong established on the basis Singapore based Electric vehicle’s LCC that the LCC of the EVs was not as yet competitive with the combustion engine cars that were of the conventional kind. Consumer and Societal were the two categories of the LCC of the EVs. The economic impact from the EVs perspective was measured in the consumer LCC and this was higher than the societal LCC in which the totality of the economic impact and cost of environmental externality was measured. Singapore had a low patronage of the EVs which in 2019 was

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about 0.2% of the total population, and this resulted in the high cost of the batteries resulting in EVs being costly. Therefore, a policy needs to be promoted through which participation in EV purchasing is encouraged and the charging infrastructure be made accessible through an investment in this aspect. As reported by Crist, Bakker, AECOM, and Kara, the LCC of the ICE vehicles corresponding to the EVs is lower. All the same, due to the model assumptions that were made for the EVs, for the EVs reported by EPRI, the LCC was lower in comparison to the ICE vehicle. A holistic comparison between the LCC of ICE vehicles and EVs is difficult as different countries have differing assumptions, peculiarities, and methodologies. At the same time, the LCC of the BEVs could be reduced gradually by bringing about necessary policies and speedy implementation thereof as it would reduce the cost of batteries significantly.

1.6.1. Dynamic Modeling Hybrid System Well known researchers named as Onar, Alam, and Uzunoglu performed dynamic modeling of a SC/FC hybrid system whereby during steady-state, power demand and load switching excellent characteristics were found by them for vehicular applications. If in the control system the power-sharing technique was optimized, the FC was assisted by the SC. From the advanced vehicle simulator (ADVISOR) software’s urban dynamometer driving schedule (UDDS) the analysis model was referred to the profile data. The power-sharing system was designed in a way that the SC and FC could be arranged in parallel. Before loading, the sources were connected to the switch, and the algorithm was followed by the opening of the switches, which in turn was dependent on the deceleration and demand for power. In order to improve the power converter system, the system was embedded with a PI controller. For the hybrid power generation system wind/SC/FC was used by Onar in the dynamic modeling proposed by them. Demand load was supplied by the wind turbine, and an electrolyzer was fed with the excess energy. Hydrogen is generated by the electrolyzer, which can then be stored or used immediately by the FC system. Any demand for load that is additional is fulfilled by the FC system.

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Just for short periods, another option for supporting a high-power demand is the SC where the maximum power has been reached by the wind turbine and the FC. A wind turbine, power factor correction capacitors, two IGBT inverters, a hydrogen storage tank, supercapacitors, a two-winding coupling transformer, an asynchronous induction generator, a double bridge rectifier controlled by a thyristor, an electrolyzer, an dc/dc converter and a FC comprise the dynamic simulation model.

1.6.2. Dual Clutch Transmission (DCT) in PHEV For a PHEV, a researcher named; Song performed a study of an EMS. For transmission, a dual-clutch transmission (DCT) comprises this PHEV instead of a gear reduction. It analyzed the vehicle’s dynamic performance like the consumption of its fuel. This system is based on a braking and driving management system and having been built with a serial/parallel (S/P) HEV the system involves far more complex control strategies. Three parameters determine the driving mode, namely the SOC, the throttle and the vehicle’s speed. The braking system is applied with a parallel braking. The simulation result was analyzed using two driving cycles, UDDS, and NEDC. Compared to the control strategy developed by PHEV and ADVISOR lesser fuel is consumed.

1.6.3. Improved Power-Train for HEV In a new vehicle topology power-train, Bauman, and Kazerani introduced a combination of a FC-SC battery. For a FC in parallel, a dc-to-dc converter with low power was connected to the battery by using power dc/dc converter in this superior technology and across the diode this was followed by antiparallel switch. Due to the usage of a high-efficiency path during the battery’s discharging and charging, a boost converter that is low power and a majority of the current of the transient power being provided by a SC, a number of advantages accrue from this advanced topology which include reduction in the mass and cost resulting in a prolonged life for the battery and simple modification being offered to a PHEV. This is unlike the other conventional system topologies where a battery with a bidirectional converter is used parallel to a dc/dc converter for the FC and the other topologies without the anti-parallel switch in a similar system.

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1.7. CURRENT CHALLENGES AND PROBLEMS IN ELECTRICITY-POWERED VEHICLES For the next generation, the most promising option as a mode of transport is the HEVs. In light of the substantial increase in prices of crude oil during the last few decades, consumers have had no choice but to look into other modes of transport which use alternative energy sources. Almost zero hazardous emissions are emitted by the BEV and PHEV based hybrid vehicle, and they are also far more efficient in comparison to the ICE-based hybrid vehicles (Figure 1.6).

Figure 1.6. Current challenges and problems in electricity-powered vehicles.

The performance and efficiency of PHEV has been improved through the contributions made by a number of researchers. The intelligence systems and reliability of these still requires a lot of work even though the existing research enables the technologies to result in a good performance of the HEV. The HEV still face a number of challenges (these have been enumerated below) and before the HEV become fully operational in the market a number of factors have to be considered: • • •

Drawbacks related to power density and energy are associated with the application of RESs to vehicles. These vehicles still come at a very high cost. The infrastructure for the refueling of these vehicles at the refueling stations needs to be looked into. For instance, one can introduce an exchange tank as an alternative where for instance, a small storage tank is required for a light vehicle.

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•

•

A detailed study needs to be conducted on the production of hydrogen for FCs, which would include the storage tank and delivery systems. To become a reality, the refueling stations would require trillions of dollars, and a study was done on this aspect as per Bossel (2004). It is necessary to conduct a study on the rapid recharging system as it is time-consuming to recharge a plug-in BEV. For hybrid vehicles and BEV, the production has seen a positive impact by the manufacturers of cars through the use and development of lithium-ion batteries that recharge are shorter time and are lighter. The new battery technology, for instance, is being used in the cars like Tesla S, Chevy Volt, and Nissan Leaf. Before marketing of the HEVs and BEVs can be done publicly, all these issues need to be looked into properly.

1.8. ENERGY STORAGE IN ELECTRIC VEHICLES Storing of energy during regenerative and rechargeable braking is the main function of storing energy in EV. SCs and battery are the main devices for energy storage. Typically, one-third or even more size and weight of the vehicle consists of batteries. Having a life cycle that is low, maintenance is required by them within 1 or 2 years. These devices need to be recharged after they provide energy/ electric power in limited capability. The development and commercialization of advanced battery has seen a major role being played by the United States of Advanced Battery Consortium. As a result of the research, there is to be a likely increase in the power and energy capabilities; life can get extended as also the cost and weight of the batteries. In normal, SCs are designed for power assistance or secondary storage, and one-tenth of the electric energy that is consumed by the battery is provided by SCs (Figure 1.7).

Figure 1.7. Energy storage in electric vehicles.

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The recharging time of the HA + EV definitely gets shortened once the storage capacity of the SCs is increased. In order to compensate for the wide range of discharge voltage, an electronic controller is required as the voltage of SCs is in direct proportion to SOC. Both the storage devices’ drawbacks need to be solved through a new technology. For both the devices, proper control of the energy storage can be seen as a challenge as well as an opportunity whereby energy and power management system can be discovered.

1.9. SYSTEM CONFIGURATION AND DRIVE TRAIN STRUCTURE Two or more energy sources are present in hybrid vehicles, one being the assist power source and the other, the main power source. Normally, in HEV, the vehicle propulsion system is designed in parallel, series-parallel, and series. Compared to the series-parallel and parallel configuration, a series hybrid drive train is cheaper and not as complex. All the same certain disadvantages may be faced by a series hybrid if ICE is used like maximum size of traction motor, an additional generator, and lesser efficiency after energy has been converted twice. The sizing of the HEV depends upon the power, cost, and application; hence, for selection on sizing of the HEV, this research study becomes important (Figure 1.8).

Figure 1.8. System configuration and drive train structure.

Automotive companies have started some research and some of these become interesting especially for HEV like that for the DC dual-voltage system. An efficient, dependable, low-cost, and practical power distribution can be brought about through this dual-voltage architecture. This has become an important challenge for the automotive industries of today.

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1.10. POWER ELECTRONICS Power switching devices that are associated with the control systems that can be and are used to drive EMs are the power electronics. To bring about an improvement in the efficiency of the drive system of the vehicle in terms of fuel efficiency and driving range, a major role is played by these requirements in HEV. Furthermore, HEV may see the market due to these systems’ affordability and reliability. Converts/inverters, power switching, control, and integration to any electronic device is included in the task of system. Technical challenges faced by the power devices include issues like EMI considerations, switching losses during turn-off and turn-on, noise, and switching frequency of PWM operating mode.

1.11. ADVANTAGES OF ELECTRIC VEHICLES Electric vehicles have progressively been building the headline in current times. It has been observed that significant vehicle maker Volvo, for example, has declared that each vehicle they introduced after 2019 had an electric engine, and that the recent UK Government needs to see their streets from petroleum and diesel-free vehicles by the end of 2040. Electric vehicles, sometimes called EVs, are set to be the norms. However, the question arises, what is the importance here for the normal purchaser? The majority of people do not have electric vehicles, but now an ideal opportunity to begin thinking about the benefits and disservices of electric vehicles (Figure 1.9).

Figure 1.9. Advantages of electric vehicles.

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1.11.1. No Fuel, No Emissions Many individuals get attracted to electric vehicles because of its no fuel, no emission quality. In case if anyone wish to lower their own effect on the climate through transport, at that point an EV is the way forward. The electrical motor within an electrical vehicle, works on a close circuit, so an electric vehicle does not produce any of the gases regularly associated with global warming. No petroleum or diesel is required in a completely electric vehicle, that is the incredible for carbon footprint.

1.11.2. Running Costs Since the users are not paying for petroleum or diesel to keep their vehicle running, they can save a good amount of money on fuel. At the time of composing, it costs around £63.80 to fill the normal unleaded petroleum tank for drivers of medium-sized vehicles in the UK. By examination, based on the electric vehicle people own and the tariff they are on, a full charge of their electric vehicle could cost just 96p. Anyone could even save £60 per year with Good Energy Electric Vehicle Tariff, versus the Big Six; Standard Variable Tariffs, with the extra reward of the electricity going into your EV being 100% renewable.

1.11.3. Performance The fun of owning a car usually comes from going out on the roads. In past times, the electric vehicles have not had the sleekest image. A lot many have had low expectations as to how good an electric vehicle can do as compared to the traditional engines. As so many manufacturers have heaped into the market with their own take on the electric vehicles, the level of performance of those vehicles has super increased. Electric cars are lighter, as all of their power, is produced from a standing start-their acceleration capability can give a shocking surprise. Few brands such as Tesla have done many things to enhance the perception of people regarding electric vehicles. The Tesla Model S is one of the fastest-accelerating cars available in the market, doing 0 to 60 mph in just 2.5 seconds. Well, this is not the only measure of performance of any car. People would feel happy to know that electric vehicles are much more spacious as compared to the conventional cars because of the absence of a

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large engine. Electric vehicles, in addition, provide a much smooth drive with a very low level of noise.

1.11.4. Popularity These days, if people like to stand out in the crowd, they perhaps know that electric cars are the best option. They are becoming really positive. As more and more electric vehicles are finding their way onto roads, people can see the supporting infrastructure expand. Already, there are more than 4800 charging points in UK, for example. It offers almost 7500 individual charging points, and these numbers are gradually increasing. To compare, in the year 2016, there were 8,459 petrol pumps and after the year 2000 this number has been declining. With the electric vehicles being on the road, people can see this number gradually falling while the number of charging points will increase further. Along with increasing number of charging points, the increased popularity of electric vehicles means more options to choose from for the car. Also, there are more affordable options for electric car available now than earlier, for example, the Nissan Leaf and the Renault Zoe, with some of the most popular petrol and diesel models also available in an electric version, such as the Volkswagen e-Golf.

1.12. DISADVANTAGES OF ELECTRIC VEHICLES (FIGURE 1.10)

Figure 1.10. Disadvantages of electric vehicles.

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1.12.1. Driving Range People who have done their research on electric cars, are very much familiar with the term ‘range anxiety.’ The current unit of electric vehicles are not capable of covering long distances that other fossil-fueled cars can, but the distance that can be traveled on a single charge has drastically improved recently and continues to do so. A lot many electric cars can now travel around 70 to 100 miles, and some even more than that, with just a single trip to the charging point. HEVs can do much in order to decrease range anxiety as the electric motor operates in tandem with a combustion engine. Nevertheless, most of the trips via car are observed to be less than 30 miles, which many of the electric vehicles can easily do without any problem. In a similar manner, the way that people fuel their cars need a different mindset to a fossil-fueled engine. Instead of just filling up in infrequent manner, one simply need to charge the car on a regular basis, in a similar way in which mobile phone is charged.

1.12.2. Recharge Time Going to the motorway service station as petrol gauge is flashing, refilling at the station, and getting back on the way takes almost five minutes. Thus, it can be said that it is a convenient process that everyone is familiar with. However, charging electric vehicles does not take much time. Certain estimates show that around 80% of the electric vehicles charging take place on a slow charge at home over night. In addition, a lot many businesses currently owe electric vehicle charging points in their parking lot. But charging could be a key issue when it gets down on away. It would be hard to get to a place for charging and wait for few hours and get back to the way. Unluckily, there are no five-minute recharge available for electric cars. Gradually, rapid charging is becoming more common these days; one just requires to plan it into longer journeys as even a rapid charge takes 20 to 30 minutes.

1.12.3. Battery Life A batter is an important part of an electric car, no one would be driving anywhere without the battery. For example, in UK, the batteries in electric vehicles that are in use currently have a limited life expectancy, and thus will

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require to be replaced every 3 to 10 years based on the model. Replacement of a battery is a longer-term cost calculation that requires to be remembered when a person is considering to purchase an electric vehicle.

1.13. OVERVIEW OF DIFFERENT LIFE CYCLE COST FRAMEWORKS FOR ELECTRIC VEHICLES Based on the framework developed by a well-known researcher named, Diao , the cost analysis of the life cycle of electric vehicles is mainly comprised of the tangible and the intangible cost. Further, the tangible cost includes the cost of purchase, retail cost, and the operating cost. On the other hand, the intangible cost could be the costs of driving restriction or the cost due to purchase restriction. As intangible costs, the purchase costs are those costs that the manufacturers suggest as retail cost, subsidies, and purchase tax. Whereas, the operating costs are those costs that are associated with the consumption of energy by the electric vehicle, its maintenance, use tax, and insurance. A little different from the work of Diao et al.; Kara and Sadjiva developed a framework for the total consumer life cycle cost of electric vehicles. Their framework took into account the acquisition phase, the operating phase, and disposal phase. The cost which is linked to the acquisition phase mainly comprise the manufacturers’ suggested retail price for the vehicle and level 2 charger, tax, and third-party insurance. The cost which is associated with the electric vehicles operating phase consists of the recharging electricity, battery replacement, maintenance, insurance, and tire replacement. On the other hand, the cost of the disposal is primarily associated with the scrap value of the electric vehicle, as well as the cost of battery recycling. Kara and Sadiya, unlike Diao et al. did not include the cost for subsidizing the electric vehicle, intangible cost of driving restriction and intangible cost of purchase restriction. In addition to that, Lin et al. also framed a framework on the life cycle cost of electric vehicles. Three key components were included in the life cycle cost, these are: • • •

Initial cost; Ownership cost; and Cost or income of scrapping or recycling.

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Further, the initial cost component includes: • Manufacturers; • Suggested retail values; • Purchase tax; • Registration fees; • License fees; • Government subsidies. The ownership cost consists of: • Energy cost; • Inspection and maintenance cost; • Tax; • Insurance and fees; • And other fees. This basic overview shows that the cost of ownership of a very compact passenger electric vehicle is much higher than an equivalent ICE vehicle. Although, with a continuous series of commitments and efforts for improving the technology (mainly the improvement of batteries), the electric vehicle has been projected to be cost-competitive as well as affordable in the future.

1.14. CONCLUSION In the conclusion of this chapter, basic ideologies of the electric vehicles have been discussed. This chapter also discussed about the various types of electric vehicles such as BEVs, all-electric vehicles, PHEVs. In this chapter, the application of electric vehicle in microgrid has also been discussed. In this chapter, various methods, or tactics for maximizing the utilization of RESs have been discussed. This chapter also discusses about the challenges and issues in the vehicles that are driven with the help of electricity. Towards the end of the chapter, various concepts such as energy storage in electric vehicles, system configuration and drive train structure, power electronics have been discussed. This chapter also discussed about the numerous advantages of electric vehicles such as no fuel-no emission, running cost of the electric vehicle, performance of the electric vehicle, and popularity of electric vehicle. Several disadvantages of electric vehicles such as range of the drive, time spend in recharging the battery, battery life of the electric vehicle has been discussed.

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REFERENCES 1.

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5.

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Ayodele, B., & Mustapa, S., (2020). Life cycle cost assessment of electric vehicles: A review and bibliometric analysis. Sustainability, [Online] 12(6), 2387. Available at: https://www.mdpi.com/20711050/12/6/2387 (accessed on 5 May 2021). Driveelectricvt.com. (n.d.). Introduction to Electric Vehicles-Drive Electric Vermont. [Online] Available at: https://www.driveelectricvt. com/why-go-electric/intro-to-electric-vehicles (accessed on 5 May 2021). Good Energy, (2017). The Advantages of Electric Vehicles. [Online] Goodenergy.co.uk. Available at: https://www.goodenergy.co.uk/ blog/2017/09/28/driving-change-the-advantages-of-electric-vehicles/ (accessed on 5 May 2021). Hannan, M., Azidin, F., & Mohamed, A., (2014). Hybrid electric vehicles and their challenges: A review. Renewable and Sustainable Energy Reviews, [Online] 29, 135–150. Available at: https://www. sciencedirect.com/science/article/abs/pii/S1364032113006370 (accessed on 5 May 2021). Liu, L., Kong, F., Liu, X., Peng, Y., & Wang, Q., (2015). A review on electric vehicles interacting with renewable energy in smart grid. Renewable and Sustainable Energy Reviews, [Online] 51, 648–661. Available at: https://www.sciencedirect.com/science/article/abs/pii/ S1364032115006085 (accessed on 5 May 2021). Office of Energy Efficiency and Renewable Energy, (n.d.). Electric Vehicle Basics. [Online] Energy.gov. Available at: https://www.energy. gov/eere/electricvehicles/electric-vehicle-basics (accessed on 5 May 2021).

CHAPTER

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BATTERY, FLYWHEELS, AND SUPERCAPACITORS

CONTENTS 2.1. Introduction....................................................................................... 28 2.2. Batteries............................................................................................. 31 2.3. Battery Parameters............................................................................. 34 2.4. Use of Batteries in Hybrid Vehicles ................................................... 35 2.5. Battery Modeling............................................................................... 37 2.6. Supercapacitors................................................................................. 38 2.7. Flywheels.......................................................................................... 41 2.8. Existing Applications of Flywheel Battery........................................... 46 2.9. Energy Management of The EV........................................................... 47 2.10. Energy Storage Systems (ESSS) Requirements................................... 50 2.11. Conclusion...................................................................................... 53 References................................................................................................ 54

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In this chapter, the basics of battery, flywheel, and supercapacitor are discussed. The chapter also discussed several battery parameters. It also demonstrated the use of batteries in hybrid vehicles. It also highlighted the concept of battery modeling. It also shed some light on the existing applications of flywheel battery. It also stated energy management of the EV. It also discussed energy management of the EV. At the end, it states energy storage systems (ESSs) requirements.

2.1. INTRODUCTION There are a wide range of varieties and sizes of EVs available. Though, in almost all street vehicles, the key part of vehicles is battery. In the traditional EV, the battery is the only energy store, and the part with the greatest expense, weight, and volume. In hybrid vehicles, the battery, which should consistently receive and give out electrical energy, is additionally a vital segment of the highest significance. There are some fuel cell (FC) vehicles that have been made which have batteries that are no bigger than those typically fitted to IC engine vehicles, however, it is likely that most early FC-fueled vehicles will have very enormous batteries and work in hybrid FC/battery mode. To put it plainly, a decent understanding of battery innovation and execution is imperative to anybody associated with electric street vehicles. Electric battery: A battery comprises of at least two electric cells connected together. Electric energy generated by chemical energy, the electric cell which connected together converts chemical energy to electrical energy. The cells comprise of positive and negative electrode in an electrolyte. Electric battery is the chemical reaction between the electrode and the electrolyte which creates DC power. On account of secondary or rechargeable batteries, the chemical reaction can be switched by turning around the current, and the battery got back to a charged state. The traditional rechargeable type of battery is ‘lead-acid,’ however, there are some others batteries that are getting mainstream in present-day EVs. The first EV utilizing rechargeable batteries went before the innovation of the rechargeable lead-acid battery by a quarter of a century, and there are an enormous number of materials and electrolytes that can be joined to frame a battery. Nonetheless, just a generally lesser number of mixes have been created as commercial rechargeable batteries appropriate for use in vehicles.

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At current days these incorporate lead-acid, nickel-iron, nickelcadmium, nickel-metal hydride (NiMH), lithium polymer and lithiumion, sodium-sulfur and sodium metal chloride. Also, there are some more improvements of batteries which can be mechanically refueled, the major ones being aluminum-air and zinc-air. Despite all the multitude of various prospects attempted, and around 150 years of improvement, an appropriate battery has only recently been created that permits large scale manufacturing of EVs. From the EV designer’s perspective, the battery can be treated as a ‘black box’ which has a scope of execution criteria. These criteria will incorporate specific energy, energy density, specific power, typical voltages, amphour efficiency, energy efficiency, commercial availability, cost, operating temperatures, self-discharge rates, number of life cycles and recharge ratesterms which will be clarified in the following segment. The designer also requires to see different factors on which energy availability depends. They need to understand how energy availability differs with ambient temperature, charge, and discharge rates, battery geometry, optimum temperature, charging methods, cooling needs, and likely future developments. Still, at least fundamental comprehension of the battery chemistry is very essential, if not the performance and maintenance requirements of the various types, and the most of the dissatisfaction associated with battery use, like their restricted life, self-discharge, reduced efficiency at higher current, etc., cannot be perceived. This essential information is also required concerning likely hazards in a mishap and the general effect of the utilization of battery chemicals on the climate. Reusing of utilized batteries is additionally getting more and more essential. Because of expanding gas costs and ecological concerns, battery moved electric vehicles (BEVs) and hybrid electric vehicles (HEVs) have recently drawn more consideration. In battery propelled electric vehicles (BEV) and HEV setups, the main design issue is the rechargeable energy storage system (RESS). Hence, the arrangement should be capable of having great performances during speed increase and slowing down stages, in terms of energy density and power capabilities. Though, there are some other necessary assessment parameters for RESS system like the thermal stability, charge capabilities, life cycle and cost.

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Currently, batteries are used as major storage device in many applications. These batteries ought to be sized as per the requirement, to meet the energy and power necessities of the vehicle. Moreover, the battery ought to have great life cycle performances. Nonetheless, in numerous BEV applications, the necessary power is the vital factor for battery sizing, bringing about an over-dimensioned battery pack and less ideal utilization of energy. These deficiencies could be addressed by a combination of battery system with supercapacitors. In Lu, Corzine, Ferdowsi, IEEE Trans. Veh. Technol. (2007), it is recognized that such hybridization topologies can result into upgrading the battery performance by expanding its life cycle, rated capacity, decreasing the energy losses and restricting the temperature increasing inside the battery. Omar et al. reasoned that these valuable properties are because of the averaging of the power given by the battery system. Tough, the execution of supercapacitors needs a bidirectional DC-DC converter, which is as yet costly. Moreover, such topologies require a well-defined energy flow controller (EFC). Arrangement of battery with supercapacitors hampered by Value, volume, and low rated voltage (2.5–3 V). To defeat these troubles, Cooper et al. presented the Ultra-Battery, that is an arrangement of lead-acid and supercapacitor the same cell. The recent system includes a section asymmetric and part conventional negative plate. The proposed system permits to convey and to retain energy at high current rates. The Ultra-Batteries have been tried effectively in the Honda Insight. Though, this innovation is as yet a work in progress. Somewhat recently, various new lithium-ion battery chemistries have been proposed for vehicular applications. It has been announced that the most pertinent lithium-ion chemistries in-vehicle applications are restricted to lithium iron phosphate (LFP), lithium nickel manganese cobalt oxide (NMC), lithium nickel cobalt aluminum oxide (NCA), lithium manganese spinel in the positive electrode and lithium titanate oxide (LTO) in the negative terminal.

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2.2. BATTERIES 2.2.1. Electrical Characterization It is notable that the key thought in the design of RESS in PHEV as well as BEV applications essentially rely upon the power density (kW/kg) and energy density (Wh/kg) because of the design idea. Though, the battery innovation also ought to have capable to have great exhibitions in the terms of energy productivity, lifetime, and charging rate. In this part, each of these boundaries have been examined for 10 lithium-ion battery types. The primary design ideas of PHEV uses are talked about, compared to the three arrangements of influential specialized objectives, and clarified the trade-offs in PHEV battery design. They referenced that the energy and power requirements as indicated by the U.S. Advanced Battery Consortium (USABC) ought to be in the scope of 82 W h/kg and 830 W/kg for PHEV-10 and 140 W h/kg and 320 W/kg for PHEV-40. High power/energy ratio battery (PHEV-10) and low power/energy battery (PHEV-40), these two kinds of battery identified by Pesaran. High power/energy ratio battery (PHEV-10) is set for a “crossover utility vehicle” weighing 1950 kg, and the second categories PHEV-40, is set for a mediumsize sedan weighing 1600 kg. Figure 2.1 indicates the consequences of the dynamic discharge performance test (DDP) and the extended hybrid pulse power characterization (HPPC) test. As should be obvious, the energy density of NMC (LiNiCoMnO2) based battery types D&E is in the scope of 126–149 Wh/kg, whereas the cells utilizing iron phosphate in the positive cathode indicate energy density being in the scope of 75–118 Wh/kg. It has been accounted for that the high energy density values for the LiNiCoMnO2 batteries are mostly because of the greater nominal voltage (e.g., 3.7 V) and great electrode specific capacities. Though, the circumstance in regards to the power density is not clear due to the way that power is changing over a wide reach. Figure 2.1 shows that lone cell type D utilizing LiNiCoMnO2 has the most powerful density around 2100 Wh/kg. This outcome is for the most part because of the great specific impedance.

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Figure 2.1. Power density versus energy density at room temperature.

The outcomes show likewise that iron phosphate-based battery types B and H have great power performances being in the scope of 1580–1650 W/ kg. Though, in light of the USABC objectives, every one of them tried cells can meet the power necessities of 320 W/kg with special case of battery F 290 W/kg. However, the best energy density type battery is type E, the power capacities of this battery are restricted in contrast with the battery’s types B, D, and H, which demonstrates that this battery is more fitting for BEV applications. The introduced brings about figure referenced above depends on the maximum discharge C-rate at 50% state of charge (SOC).

2.2.1.1. Energy Efficiency In PHEV applications, at the time of charge and discharge phases the energy efficiency can be regarded as one of the main factors. High-energy efficiency is required in order to limit the increase of temperature inside a battery pack. In general, the energy efficiency of the battery types has been regarded based on the DDP test. It is well described in Figure 2.2. The energy efficiency of the NMCbased cells is approximately 94–96%. While the iron phosphate and nickel cobalt aluminum in the positive electrode show a lower efficiency in the range of 88–93%. The lower energy efficiency for LFP-based batteries can be described because of the relative lower conductivity of cathode material compared to NMC based batteries.

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Figure 2.2. Energy efficiency versus energy density at room temperature.

2.2.1.2. Charge Performances In general, it is known that PHEV applications are a key factor for enhancing the impact of traffic on healthier living environment by releasing a lower amount of carbon dioxide than the conventional vehicles. Nevertheless, the benefits of PHEV applications depend mainly on the energy storage device. Whereas, in order to improve the suitability of the battery technology in PHEV applications, the battery needs besides good power, energy efficiency performances also acceptable fast charging capabilities. It is well described that the charging process of battery involves two phases: • •

First, the main charging phase, where the bulk of energy is recharged into the battery (constant current); and Second, the final charge phase, where the battery is conditioned and balanced (constant voltage).

2.2.2. Thermal Characterization According to the United States Advanced Battery Consortium, the battery system in HEVs, PHEVs as well as BEVs must operate over an extensive operating temperate ranging from –40°C until 60°C. So as to exemplify the behavior of the battery at different working temperatures, the same DDP as defined above has been performed at –18°C, 0°C, 25°C and 40°C as described in the standard ISO 12405-1/2 and IEC 62660-1.

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2.3. BATTERY PARAMETERS 2.3.1. Cell and Battery Voltages All electric cells consume nominal voltage that gives the approximate voltage when the cell delivers electrical power. The cells then can be connected in series in order to give the overall required voltage. Traction batteries for electric vehicles are generally specifies as 6 V or 12 V, and in turn, these units are connected in series in order to produce the voltage required. In practice, this voltage will change. When a current is given out, the voltage will fall on charging, the voltage will rise. This is widely expressed in terms of internal resistance, and the equivalent circuit of a battery shown in Figure 2.3. The battery is represented in Figure 2.3 have a fixed voltage E, however, the voltage at the terminals is different voltage, V, due to the voltage across the internal resistance, R. Assuming a current I is flowing out of the battery (as shown in Figure 2.3), then as per the concept of basic circuit, it can be said that: V = E – IR In case, if the current I is zero, then the terminal voltage is equal to E, and thus, E is mostly regarded as the open-circuit voltage. If the battery is being charged, then clearly, the voltage will rise by IR. In the batteries of electric vehicle of the internal resistance must clearly be as low as possible.

Figure 2.3. Simple equivalent circuit model of a battery. This battery is composed of six cells.

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2.4. USE OF BATTERIES IN HYBRID VEHICLES (FIGURE 2.4)

Figure 2.4. Use of batteries in hybrid vehicles.

In general, there are several combinations of engines, batteries, and mechanical flywheels that all allow optimization of electric vehicles. The best-known combination is of the IC engine and the rechargeable battery. However, more than one kind of battery can be utilized in combination, and the application of batteries as well as flywheels can have various benefits.

2.4.1. IC/Battery Electric Hybrids Where efficiency of an IC engine is to be optimized by charging as well as supplying energy from the battery, a battery that can be charged rapidly is required. This used to emphasize batteries like the NiMH one. NiMH batteries are efficient, readily charged and discharged. An instance of this would be in the Toyota Prius and the Honda Insight. Both of these are very successful hybrids that make use of NiMH batteries. These days, on recent versions, LIBs are being used. A zinc-air battery would be of no use in such situations, as it cannot be electrically recharged. Such kind of HEV, that is an IC engine with a battery cannot be recharged from the mains-was the most common one until recently. It appears that

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the majority of such kind of vehicles use NiMH batteries, with a storage capacity usually between the range of 2 to 5 kWh. It is important to note that the energy stored in a normal car battery is between around 0.3–1.0 kWh. The modern hybrids like the mains rechargeable Chevrolet Volt, use LIBs.

2.4.2. Battery/Battery Electric Hybrids Different types of batteries have different features, and at times, they can be combined to give optimum outcome. For instance, an aluminum-air battery has a low specific power and thus, cannot be recharged. However, it could be used along with a battery that recharges as well as discharges very rapidly and efficiently-such as the NiMH battery. The aluminum-air battery could offer a baseload supplying surplus electricity to the NiMH battery when the power is not required. The energy from the NiMH battery could be supplied for accelerating or overtaking in traffic. It could be used for accepting as well as resupplying electricity for regenerative braking.

2.4.3. Combinations Using Flywheels Flywheels driving a vehicle via a suitable gearbox can be further engineered to store a very small amount of energy efficiently, that too at a rapid rate, and resupply it soon afterwards. They can be utilized with mechanisms like a cone/ball gearbox. They could be effectively used with the batteries that could not perform this. For instance, the zinc-air battery cannot be recharged in its location on the vehicle, and as a consequence, it cannot be utilized for regenerative braking, however by integrating this with an apt flywheel, a vehicle using a zinc-air battery with regenerative braking could be designed.

2.4.4. Complex Hybrids There is a wide scope for originality from designers. Two or more than two batteries, for example, an IC engine and a flywheel may attain the optimum combination. In other words, a FC could be integrated with a battery as well as a flywheel.

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2.5. BATTERY MODELING (FIGURE 2.5)

Figure 2.5. Battery modeling.

2.5.1. The Purpose of Battery Modeling Modeling, or alternatively simulating, of engineering systems is always useful as well as critical. It is mainly done for different reasons. At times, the models are made just to understand the effect of changing the approach or method by which something is made. For instance, a battery model could be made that would allow predicting the effect of changing the thickness of the lead oxide layer of the negative electrodes of a sealed lead-acid battery. Such kind of models make large use of the basic concepts of chemistry and physics, and the power of modern computers allows such models to be made with very good predictive powers. Other kinds of models are made in order to predict the behavior of a specific make and model of battery in different situations, in an accurate manner. Then, the model will be utilized so as to predict the performance of a vehicle fitted with that particular kind of battery. This kind of model depends largely on careful analysis of real performance data, rather than depending on the fundamentals of physics and chemistry. Although, all modeling of batteries is difficult as well as unreliable. The performance of a battery relies on reasonably easily measurable quantities, for example, its temperature, and performance characteristics such as voltage. In addition, it also depends on different parameters that are harder to precisely specify, such as the age and the way the battery has been utilized or misused in the past. Manufacturing tolerances and variations between the different cells within a battery can also have a major impact on overall performance. The consequence of such problems is to provide an introduction to the task of battery simulation and modeling.

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2.5.2. Battery Equivalent Circuit In the process of simulating the performance of a battery, the first task is to make an equivalent circuit. Basically, this is a circuit which is made up of elements where each element precisely has predictable behavior. A key disadvantage of such kind of circuit is that it does not explain the dynamic behavior of the battery. For instance, if a load is connected to the battery, the voltage will instantly change to a new value. Actually, this is false, instead the voltage takes enough time to settle down to a new value.

2.5.3. Modeling Battery Capacity It has been noted that the capacity of a battery is further reduced if the current is drawn quickly. Drawing 1 A for 10 h will not take the same charge from a battery as running it at 10 A for 1 h. This phenomenon is highly important for electric vehicles, as in this application to be capable of predicting the effect of current on capacity, both when designing vehicles as well as making instruments that calculate the charge which is left in a battery (battery fuel gauge). The best possible way of doing this is to make use of the Peukert model of battery behavior. While not being much accurate at low currents, for higher currents it models battery behavior well enough. The starting point of this model is that there is a capacity, known as the Peukert capacity, which is constant. This is given by the equation: Cp = I k T

where; k is a constant (usually around 1.2 for a lead-acid battery) and called the Peukert coefficient. This equation assumes that the battery is discharged until flat, at a constant current I, A (ampere), and that this will last T (time) hours. It is important to note that the Peukert capacity is equivalent to the normal amphours capacity for a battery discharged at 1 A.

2.6. SUPERCAPACITORS Supercapacitors are also called double-layer electrical capacitors (EDLC) or ultra-capacitors, and the energy density is higher than conventional capacitors, usually thousands of times higher than capacitance electrolytic capacitors. For example, the capacitance of a particular electrolytic capacitor may vary from tens to milli-farads (Figure 2.6).

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Figure 2.6. Supercapacitors in EV. Source: Image by SpringerLink.

The capacitance of a supercapacitor of the same size is several farads. The largest supercapacitor has a capacitance of 5,000 farads. The maximum energy density in production is 30 Wh/kg. However, the strong density and capacitance of a supercapacitor can have values in the thousands of farads, the cell voltage is limited to about 2.7 V to prevent voltage depletion and supercapacitor cell deterioration. The basic structure of the cells is mainly cylindrical. But now, there are commercial liquid capacitors available. Technical progress is similar to the use of conventional capacitors. Supercapacitors cells BCAP310F and BCAP1500F were used in many studies. Its properties are based on the ability of the two layers between the solid conductor and the electrolyte. The structure of the elements consists of two activated carbon electrodes and a simulated electrolyte separator. The electrode consists of a metal collector covered with active material on both sides and the surface area part that is needed for a double layer. The two electrodes are separated by a membrane known as a separator, which prevents electrons from conducting the conduction through physical contact with the pole, but allows ions to be transferred between them. The composite material is then packaged in a cylindrical container. Organic electrolytes surround the system. These two electrodes are taped and connected to the (+) and (–) external connections of the supercapacitor.

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2.6.1. Electrical Characterization Equivalent series resistance and capacitance of supercapacitor calculation methods: •

Using an Electrochemical Impedance Spectroscopy (EIS): It is generally utilized in the classification of electrochemical behavior of different energy storage devices. Impedance analysis of linear circuits is observed to much easier than the analysis of non-linear ones. Electrochemical cells are not linear. However, doubling the voltage will not eventually double the current. The electrochemical systems can possible be pseudo-linear. In general, EIS practice, a small AC signal (1–10 mV) is applied to the cell. With a small potential signal, the system is pseudo-linear. The supercapacitor is basically polarized with a DC voltage. A small voltage ripple, usually 10 mV, is superimposed on the DC component. The ripple frequency is further swept between 1 MHz and 1 kHz. The calculation of the current amplitude as well as in regards to the injected voltage allows the determination of the real along with imaginary components of the impedance as a function of the frequency. The supercapacitor capacitance C and the series resistance (ESR) are deduced from the experimental results, respectively. C = – 1/2 *π* Im(z) * f ESR = Re(z)

where; Im (z) is the imaginary component of the supercapacitor impedance; Re (z) is the real component of the supercapacitor impedance; f is the frequency.

2.6.2. Thermal Characterization Heat production in the case of supercapacitors is exclusively related to Joule losses. The supercapacitors support current up to 400 amperes or more based on cell capacitance and applied technology. The repetitive charge, as well as discharge cycles of the supercapacitor, cause a major warming even though the equivalent series resistance value is around the m*Ω according to the capacitance. Different authors showed that the supercapacitor ESR differs according to the temperature. Different authors have studied the effect of the temperature as well as the voltage on the supercapacitors aging. They have recognized a model

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which allows the analysis of self-accelerating effects of degradation caused by increased temperatures as well as voltages. This model is a holistic simulation model that correlates thermal and electrical stimulation of supercapacitor modules with an aging model. This increase in temperature can have the following results: •

The fall of the supercapacitor characteristics, mainly ESR, selfdischarge, and lifetime, which affect its reliability as well as its electrical performance. • The pressure inside the supercapacitor is increased. • A premature aging of metal contacts, the repetitive heating as well as substantial temperatures can rapidly decline the terminal connections of the supercapacitor. • The evaporation of the electrolyte and thus, the devastation of the supercapacitor if the temperature exceeds 81.6°C which is the boiling point of the electrolyte. Thus, it is critical to know as well as understand the heat behavior of the supercapacitor cells and modules. This eventually leads to an estimation of the space-time evolution of the temperature. It deals with the thermal modeling and heat management of supercapacitor modules for vehicular applications. The thermal model developed is grounded on thermal-electric analogy and further, allows the determination of supercapacitor temperature. Based on this model, heat management in supercapacitor modules was studied for vehicle applications. Hence, the modules were submitted to real life driving cycles, and the increase of temperatures of supercapacitors was estimated as per the electrical demands. The result of simulation shows that the hotspot is located in the middle of supercapacitors module and that a forced airflow cooling system is necessary. For the supercapacitor behavior, the device is generally characterized by the use of EIS for varied temperature.

2.7. FLYWHEELS High-speed flywheels are well-known emerging technology with certain features that owe the potential of making them viable ESSs abroad vehicles. Several researches have been done to find out the competitiveness of highspeed flywheels on the basis of cost as well as fuel economy when compared to the well-established energy storage technologies of batteries as well as ultracapacitors in a FC-based series HEV (Figure 2.7).

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Figure 2.7. EV specific aluminum lightweight flywheel. Source: Image by EV West.

At the time of increasing concerns over the security of energy, air pollution, climate change, and fossil fuel reserves, alternatives to conventional automobile powertrains based on the internal combustion engines (ICEs) are being largely investigated. Powertrains that are based on the FCs are one of those alternatives that have the major potential of overcoming various problems endemic to ICEs. FCs characteristically have a higher “tank to wheel” efficiency as compared to ICEs, and depending on how the hydrogen fuel is produced, they have the potential to release significantly fewer pollutants. Hybridizing a FC with an ESS can have many positive impacts. The ESS can be designed to meet the requirements of transient power that further characterize the normal driving conditions. With the ESS handling the transient loads, the FC must provide the average power. This eventually enables the FC to be downsized that reduces costs and improves efficiency. The ESS offers the additional benefit of being capable of storing energy captured via regenerative braking. Most of the work done in the field of

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designing and optimizing series HEVs has considered batteries as well as ultracapacitors as the ESS. As earlier research has produced a major deal of information related to optimal ESS technologies and configurations, it has highly neglected high-speed flywheels as an ESS technology that could deal with the batteries and ultracapacitors.

Flywheels are basically a mature energy storage technology, though in the past, volume, and weight considerations have restricted their application as vehicular ESSs. High-speed flywheels have various unique charging features. Flywheels as well as ultracapacitors have the benefit over batteries of a high cycle life with very less decrease in efficiency. Because of their high specific power, ultracapacitors as well as flywheels can charge and discharge at a very fast rate as compared to batteries. The most critical performance limitation of high-speed flywheels is that they experience quite high losses that eventually cause them to selfdischarge more rapidly as compared to ultracapacitors and batteries. For example, the high-speed flywheel goes from being fully charged to fully discharged in almost 15 minutes with no other forces acting on it apart from its internal losses. Studies done in the past have investigated the modeling as well as execution of flywheel systems in vehicles. Although, prior research has not provided a direct comparison between batteries, ultracapacitors, and high-speed flywheels functioning as the ESS in an HEV. The various study aims to make that comparison.

2.7.1. Flywheel Model The flywheel model is based on the data for a 540 kJ, 60 kW flywheel from “Flybrid Systems.” In the model, the flywheel handles requirements to accept or produce a specific amount of power to the maximum level allowed by its current SOC and power rating. The losses of flywheel are considered for through a lookup table that basically co-relates the loss of power to the speed of the flywheel. In a given time step, the losses were found by taking the average speed of the flywheel over that particular time step and after that, finding the corresponding loss of power. It must be explicitly made clear that not every specification for this flywheel is publicly available yet, and some of the data needed for studies were acquired from a personal correspondence with Flybrid Systems. To the

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best of the author’s knowledge, Flybrid Systems is the only manufacturer of mechanically integrated as well as high-speed flywheels for automotive applications. As a result, to go ahead with the analysis, their data was utilized. As an ESS, a flywheel functioning is usually combined into a powertrain in one of the two manners. In the first way, which is known as electrical integration, the flywheel is usually connected via a fixed ratio gearbox to an electric generator or motor that is connected to the electric bus. This method basically allows for much more flexibility in packaging the flywheel system in the vehicle. On the other hand, in the second method, which is known as mechanical integration, the flywheel is linked to a continuously variable transmission (CVT) that interfaces with the driveshaft through a clutch. Integration of flywheel through the CVT is very efficient. As the flywheel does not get power that has been exposed to motor or generator, gearbox, and wheel/axle losses. For this specific reason, a mechanically integrated high-speed flywheel was used in various studies. Prior research has depicted the efficiency of the CVT to be around 85%, irrespective of the power passing through it. Hence, the CVT model is treated as having a fixed efficiency of 85%. For high-speed flywheels, proper packaging is a critical factor so that the device is contained in the event of a rupture. The combined mass of the standard flywheel along with its flywheel is almost 15 kg. Through correspondence with a Flybrid representative, it was predicted that with high-volume production a CVT for a 60-kW flywheel would weigh almost 48 kg. As per Flybird’s cost estimates based on the mainstream automotive market production volume, the cost of the standard flywheel is between $1000 and $3000. Whereas, the CVT should cost no more than $1500, which brings the total flywheel system cost to between $2500 and $4500 or $42–$75 per kilowatt. The standard flywheel usually weighs 15 kg and stores 540 kJ, the size of the flywheel can be varied. It was also determined that the mass of the flywheel rotor could be reduced by 20%, although the mass of the flywheel system cannot be increased, the reason being the 15 kg version is the largest flywheel that the bearings could handle.

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If more energy storage is needed from the flywheel, then multiple flywheels should be utilized. Its multiple flywheels are utilized together, the mass, cost, energy storage, and the losses are increased by a factor equal to how many flywheels are integrated together and added to the fixed cost as well as mass of the ancillary flywheel equipment. If the mass of the flywheel is decreased by 20%, the mass and the cost scale linearly, yet the power losses remain the same, as the same bearings are utilized in the standard flywheel.

2.7.2. Ultracapacitor Model The ultracapacitor model is based on a 350F ultracapacitor. The model treats the ultracapacitor as a source of voltage, E, in series with an ideal resistor, R, which actually signifies the internal resistance of the device, and V terminal is the voltage measured at the terminals of the ultracapacitor. The open-circuit voltage of the ultracapacitor being a function of the SOC is basically defined by a lookup table published by the manufacturer. The resistor has a constant value. It is set to the value which is informed as the internal resistance in the datasheet of the device, 3.2 m. This ultracapacitor has a specific power of 4.3 kW kg–1 and a specific energy of 5.62 Wh kg–1. Various literature quotes ultracapacitors to cost between $0.01 and $0.015 per Farad in high-volume production. Hence, this sets the cost between $3.50 and $14 per cell and between $13 and $51 per kilowatt.

2.7.3. Battery Model Batteries generally used are lithium-ion cells and are commercially available. These are marketed by their manufacturer for use in HEVs. Lithium-ion batteries are highly used as their specific energy as well as power ratings are among the highest of all the battery technologies available in modern days. The cells that are used in flywheels have a specific energy of 108 Wh kg and a specific power of 3.3 kW kg–1. The model treats the battery as a voltage source in series with a resistor similar to the ultracapacitor model. –1

Just like the ultracapacitor model, E varies with the SOC and R is constant. Although, the technique of determining E and R for the battery model vary from the method utilized for the ultracapacitor model. To obtain E and R, the battery model utilizes different procedure that can be acquired from the constant current discharge curves on the datasheet of the battery.

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The manufacturer of the battery has issued a cost of $110 per 6 cells. However, this price is only quoted for small shipments intended for experimental use. In addition, it is considerably higher than most cost estimates for lithium-based batteries in the year 2010. A much more reasonable estimate of the cost was obtained that set the cost of batteries at between $1000 and $2000 per kilowatt-hour, or between $33 and $66 per kilowatt.

2.8. EXISTING APPLICATIONS OF FLYWHEEL BATTERY Rising demands on technical parameters of powertrains and simultaneously requires to minimize the consumption of energy and contemporary re-usage of energy from renewable sources, have ultimately led to inventions of modern and advanced technologies of flywheel batteries as well as their applications into new fields (Figure 2.8).

Figure 2.8. Existing application of flywheel battery. Source: Image by Pixabay.

Along with the stationary flywheel batteries, mobile applications play a key role these days, such as in transportation. Mobility requirements have led to flywheel miniaturization in respect to its weight and volume. Some examples are shown as given below: •

•

Small flywheel systems for short-term voltage balancing in the power grid: Such systems have comparatively small specific density, as the weight and volume are limited. On the other hand, a high specific output power can be attained. Usage of the flywheel to balance the peak voltage of electric vehicles: The objective here is to significantly minimize high currents from the original battery power for the traction engine. The battery life is prolonged by decreasing the peak current.

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•

•

•

•

•

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Wind-diesel generator with flywheel battery: During the start of the 21st century, the wind-diesel power station along with a kinetic energy accumulator was designed. Diesel generator and flywheel compensate wind oscillations. Cheers to the flywheel execution, the wind unit is capable of delivering high power just within a period of 2 minutes only. Flywheel for photovoltaic systems: Integrating flywheels into a photovoltaic system, the allowance of the energy supplies up to almost 30% can be attained. Flywheel in the power grid: Flywheels with large capacity of approximately 10 MJ can be executed in the power grid, which eventually results in the rise of the network quality. This system is capable of stabilizing voltage in the power grid with minimal tolerance for more than 10 minutes. High-power-UPS device: By combining tens of flywheel batteries, a high-power UPS device can be made. Delivery of an enough amount of energy experiments with plasma, rushing of heavy materials and super-large UPS systems, signify potential instances. The maximum power of approximately 50 MW can be effectively delivered from the UPS devices for more than 10s, with total efficiency beyond 90%. Same kinds of flywheels have been tested for city buses as well as rail vehicles with savings up to tens of percent. Applications in aerospace industry: Flywheel battery can substitute or balance the standard batteries in some applications in on-board systems, which ultimately results in considerable savings in weight as well as total volume of battery systems.

2.9. ENERGY MANAGEMENT OF THE EV To examine the effect of temperature, a two-stage energy management strategy is proposed. This further includes the benefits of both rule-based as well as optimization-based methods proposed. As a fundamental principle, it is required to meet the incessant parts of the power need of the electric vehicle by the battery. In such way, the effects that affect the battery life negatively are reduced to a minimum. The instantaneous demand of power and the recoveries from the electric vehicle are requested to be met or recovered by the ultracapacitor because of the rapid response time.

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Additionally, there is an exchange of energy between the battery and the UC in order to keep these storage units, that are amongst the key tasks of the EMS, reliable, and always available. The objective is to attain the sharing of power between the battery and UC by finding out the weighting factors in the most appropriate way. For this purpose, a search space was determined and distinct constraints were established as per the demanded power and the SOCs of the storage units. Such rules have been established by using reference (Trovao et al., 2013) and are detailed in the relevant work. Later, these values were optimized by making use of the PSO method in the specified limits. The increasing functions of the electric vehicle or electronic system call for critical improvements of the power supply system. Many years ago, a comprehensive introduction of a higher system voltage level, 42 V, initially in a dual-voltage 14/42 V system, was regarded as a feasible solution. Nevertheless, the cost or benefit ratio correlated with this kind of configuration in systems working at 42 V or less turned out to be very low for extensive implementation. In addition to that, the electric force that can be produced at this voltage level is usually regarded too low to make mildHEVs very attractive. Simultaneously, various hardware components for the conventional 14 V system experienced substantial technological progress. For instance, enhanced 14 V claw pole (Lundell) alternators were created that can unceasingly generate an electric power output of 3 kW or more. AGM batteries verified at least three-fold longer shallow-cycle life, as compared to conventional SLI batteries. As a result, the introduction of highlevel energy management control strategies can assure system robustness as well as optimal energy efficiency and hence, help stretch the boundaries of the 14 V system. are:

Energy management functions can be separated into two groups, that • •

Power supply management (PSM); and Power distribution management (PDM).

2.9.1. Power Supply Management (PSM) PSM control of the on-board electric generation, that is, control of the alternator setpoint in traditional electrical systems, directing at optimization of all of the electrical function availability, vehicle performance (e.g.,

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reduced alternator load when maximum acceleration is demanded), battery life or fuel consumption (e.g., reduce alternator output at idle to allow for lower idle speed). On the other hand, many of such functions can be regarded as the state-ofthe-art in modern voltage regulation, mainly the latter has garnered growing attention lately. Electric generation ultimately contributes pointedly to fuel consumption, at least in real-world conditions. An average alternator output of 1 kW includes as much as 1–1.4 L gasoline fuel consumption per 100 km, based on vehicle parameters as well as driving conditions. Decoupling the electric generation from the demands of loads can meaningfully decrease this specific fuel consumption contribution by improving the system efficiency of the engine and alternator at any given point in time. This will ultimately, introduce supply voltage fluctuations into the electrical system and thoroughly exploit the battery as a short-term energy buffer. Much more advanced strategies of PSM are of course required for HEVs, where electric generation plays a major role.

2.9.2. Power Distribution Management (PDM) PDM, in general, is used to schedule the allotment of available energy and power to electric loads on a component or subsystem level. It should guarantee the controlled function delivery of individual electric features by prioritization. In cases where a power deficiency takes place, the PDM algorithm aims at guaranteeing rail voltage stability, robustness, and charge balance, along with reducing the battery charge throughput in the case of peak loads. Based on the definition of electric feature priorities, a PDM strategy can command a temporary functional degradation under appropriate conditions. In such cases, a careful balancing of priorities is needed, mainly for the functions that are directly understandable by the customer. Advanced PDM algorithms will eventually schedule electric feature functionalities in a dynamic manner instead of statistic manner. Management of electric energy actively utilizes the energy storage system that are battery, supercapacitor, etc., and as a result, depends largely on accurate status information about the device. A battery monitoring system (BMS) has to bring these essential inputs to the energy management control system.

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2.10. ENERGY STORAGE SYSTEMS (ESSS) REQUIREMENTS 2.10.1. Robustness and Reliability In the last few years, the automobile industry has literally undergone a major revolution in total vehicle reliability. With a greater number of parts or components along with the number of potential failure modes, now it has become very important for a component to provide six sigma (