Electric Vehicles (EV)

Electric vehicle transmission

This page represents an overview of electric vehicles at 2023 based upon personal research, no representation of accuracy of information is made.

Brief History of Electric Vehicles

Electric vehicles rely on propulsion from electric motors sourcing power from a battery pack.
Much can be said of the history and development of the electric vehicle (EV) and electromobility both globally and at local level in the United Kingdom. In 1832, Scottish inventor Robert Anderson was credited with inventing a first electric vehicle link opens in new window

ZF's website also gives a comprehensive history of electric vehicles link

1930's - Inventor, Nikola Tesla is said to have developed an electric car in the 1930's known as the Pierce Arrow.

2004 - Graphene is discovered and developed at the University of Manchester. Graphene is a 2D material derived from graphite having properties of strength 100 times stronger than steel with high conductance offering possibilities to build supercapacitors and lightweight, high strength composite components using 3d printing techniques.

2024 development of EV's seeks to maximise range by optimising battery chemistry, motor efficiency and power management whilst improving safety.

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Benefits offered by Electrification of Vehicles

100% electric vehicles do not have an internal combustion engine therefore consume no combustible fuels during driving.

Low or Zero Exhaust emission

EVs have low emissions meaning better quality breathing air and less noise in comparison to Internal Combustion Engine Vehicles (ICEVs).

The key benefit of pure electric vehicles is said to be Zero exhaust emissions, with hybrid vehicles (with ICEV) having reduced exhaust emissions than fully fossil fuel powered combustion engine driven vehicles. Lowered environmental emissions means less pollution at a time when governments are seeking to reduce carbon footprint and offset climate change said to be caused by greenhouse gases and heating of the Earth's atmosphere. The long term effect of climate change is rising sea levels and subsequent flooding due to global melting of glaciers.

International agreements promote government policies to encourage motorists to dispose of combustion engined transport in favour of electric transport mobility termed electromobility. Incentives include heavy taxation on traditional fossil fuel powered transport compared to low taxes and finance incentives to encourage purchase of electric vehicles.

Government ambitions indicate that target dates are set for terminating manufacture of fossil fuel powered vehicles.

Low Noise Travel & Comfort

Electric motors develop higher torque at higher revs per minute (rpm) compared to the internal combustion engine (ICE) which produces peak torque in a narrow rpm band.

Further benefits of electric motors include simplicity with less moving parts than a traditional combustion engine and low noise with reduced vibration.

Electronic control systems mean soft start programming is available allowing gradual increase of speed for smoother driving without the need for manually operated clutches. Electronic control of battery charging can increase battery cell lifespan further increasing efficiency.

EV Battery Off-grid Power Storage

Vehicle battery packs provide components to build off grid power storage systems which can be recharged by renewable energy sources such as solar panels, wind generators, and water power (hydroelectric).

EV batteries where power output has reduced and come to end of life for vehicle use may be re-purposed as alternative energy storage solutions for example domestic use.

Smart Rechargeable Electrical Energy Storage Systems (REESS) have potential to in feed the national electricity grid from high power vehicle batteries offering increased sustainablity.

Living accommodation (which may include houses, caravans, motorhomes, mobile homes) with Off-grid power systems provide resilience in the event of central power generation failure much like an internet.

Vehicle to Grid V2G technology

Off-grid DC energy storage in vehicle batteries has potential to connect to the national grid to provide back up power supply.

Simplicity

Electric vehicles have Less moving parts than internal combustion engine powered vehicles

Development of magnetic resonance wireless power transfer for vehicle battery charging.

Reduced Servicing Costs

Regenerative braking has been used with success on commercial and industrial vehicles to increase efficiency.
Regenerative braking generates power using the vehicles kinetic (moving) energy to decelerate reducing use of friction linings allowing for increased service intervals. Basically the brake pads and disc last longer.

Autonomous transport

Development of autonomous (self driving) vehicles : see Google Waymo : Self driving car is a progressing technology. Image sensing, global positioning and robotics can be integrated with electric vehicles for both transport, constructon and security applications.

Financial incentives to operate electric vehicles

The UK government is providing financial incentives to operate electric vehicles through the Office for Zero Emission Vehicles (OZEV).

Plug in Vehicles Grant scheme offers discounts built in to the purchase price of the vehicle.

Legislative pressure

International agreements to reduce climate change encourages governments to create legislation to reduce carbon emissions and increase taxes on polluting vehicles. The target of emission control legislation is to reduce the number of vehicles with petrol and diesel engines by increasing taxes to persuade consumers towards zero emisson technologies.

Disadvantages of Electric Vehicles

Engineers are actively working to reduce the problems associated with electric vehicles :

Capital Outlay

At March 2023 upfront capital cost of the cheapest new electric cars starts at around £8k for the most basic upgraded 4 wheel bike with most small electric cars costing over £30k upwards.
Capital purchase cost of EV's may be balanced against whole life asset cost taking account of purchase incentives and potential to use renewable energy technologies such as solar, hydro, and wind power generation.

Electricity

EVs create increased demand for electrical power, much of which is controlled by a few large utility companies, however this is no different to the control oil producers exert over combustion engine powered vehicles.
Nuclear power generation provides an energy source to replace fossil fuels.

Hydrogen fuel cells may be used to generate electricity. The Sun, Wind turbines and Water power may be used to generate electricity.

Electrical demand loads may be controlled by computer software using the vehicle communications networks.

UK EV Charging Infrastructure

Limited availability of high current 3-phase charging points across the UK - more become available as network develops.

Capacity of electric vehicle charging points is restricted by available power supply network especially in rural areas such as Shropshire & Mid-Wales.
Fast charging requires high voltage therefore availability of local industrial 3 phase power supply.

Limited EV range

The range of an EV depends on the battery capacity and output which has many variables including temperature and load.
Cold temperatures reduce battery performance and therefore EV range.

As battery efficiency deteriorates vehicle range may also deteriorate. Electric vehicle batteries are currently deemed near end of life at around eighty percent of new capacity however end of life vehicle batteries have applications for domestic power storage.

EV battery recharge time

Battery capacity is proportional to time taken to recharge batteries.
Fast charging to eighty percent capacity is achievable however 100% charge requires extended time.

Overcharging or Undercharging of batteries may reduce lifespan. Battery management systems limit this problem.

Comparison data introduces difficulties

EV battery range is measured in Watt Hours per Kilometer ((Wh/km) making economy comparisons difficult against engine powered vehicles.

Energy Density is measured in Watt Hours per Litre (Wh/L).
Energy density per unit volume of batteries is lower than petrochemical fuels.
The proportion of vehicle load which is fuel is higher.

EV Safety Hazards

Electric Shock

electric shock

Reducing Risk of Electric Shock ;
Insulation of cabling and components. Colour coding of insulation
- Orange insulation is typically used to identify high voltage cables in electric vehicle wiring systems.
Personal protective equipment and specialist tooling meeting safety standards.
Mechanical protection and seperation.
Warning Labelling
Training and safe working procedures, following manufacturers procedures
Towing electric vehicles may generate unwanted electrical energy posing unanticipated risks of shock.

Fire Risk - Thermal Runaway

fire warnlabel

Thermal runaway results from uncontrolled charging of EV battery packs with specific cell chemistry. Lithium Ion batteries require carefully controlled charging to avoid overheating. Engineering companies carry out much research and development to control thermal runaway and the linked fire risks.

Fire risks associated with thermal runaway of batteries ;
Battery temperature monitoring and battery cooling systems can control and reduce fire risk.
In the event of road traffic accident emergency services require specialist training to deal with EVs due to high voltages, chemistry, and fire risk.
Specialised recovery vehicles may be required to transport accident damaged EVs.

Magnetic fields

magnetic field warnlabel

Radio Frequency (RF) and Electromagnetic radiation ;
Electrical circuits can act as an aerial.

Magnetic fields can cause interference with sensitive electronic equipment and also cause unexpected movement.
Design and shielding can reduce risk.

Explosion

explosive warnlabel

Danger of release of explosive gases as electrolysis takes place in battery packs and also from fuel evaporation creating highly flammable gases.

Corrosion

Corrosion causes deterioration of electrical connections leading to high resistance, heat losses, and lowered electrical power transmission.

Graphene coatings may prevent corrosion of electrical connections whilst still allowing conductivity. Component sealing to prevent moisture ingress can reduce corrosion.

Energy Mining

Mining is environmentally damaging, costly and labour intensive.

Electric vehicles create increased demand for rare earth magnets, Cobalt, Copper and conductive metals ; Recycling mitigates initial mining costs however introduces further risks.

Controversial mining of non-renewable Lithium salts used to build Lithium battery packs. Millions of litres of water are required to produce relatively small quantities of Lithium salts.

Rare earth magnets used in permanent magnet motor technology require mining.

Child labour has been used in third world countries to mine Lithium Salts however reputable battery supply companies only use ethhically sourced raw materials.

Restricted Materials Supply

Non ferous metals such as Gold, Silver, Copper, and Aluminium, are traditionally more expensive than Iron and Steel. Lithium Salts and Graphite supplies are only found in certain regions.

Low Noise Impact risk

Electric vehicles are so quiet that pedestrians may not hear an EV approaching introducing accident risks

Independent Garage Updates Required

Independent garages have constantly faced the need for costly investment in technician training and new EV diagnostic equipment which is first rolled out to main dealers.
ICE vehicles had to meet standards such as EOBD to allow basic diagnostic equipment to communicate with a vehicle however EV's will face new protocols with the ability for remote diagnosis 'in the cloud' creating new ties to the vehicle manufacturer likely to create cloaked anti-competitive practices and potentially increase repair costs to the end user.

Autonomy

Technological development from electric vehicles to fully autonomous software defined vehicles connected to the internet of things (IOT). Hazards with autonomous vehicles not recognising safety critical situations, damage, potential cyberattacks & hacking driving legal liability to new levels. Connected vehicles risk Man in the Middle (MiTM) attacks leading to denial of service, in plain English your car is turned in to a brick!
Might be a new angle on car insurance risk.
Increased use of personal data facilitated by Block-chain technology including vehicles transmitting data such as seat position which could be used to calculate such things as the height of vehicle users which enables detailed user profiling.

Conclusion

There are risks associated with any transport system, many of which can be diminished by clever engineering, common sense and care.
EV's have to pass rigorous crash testing and safety standards before being allowed on to the UK road network.

Electric vehicle distance range and recharge time

Two of the most important questions when considering electric vehicle purchase is "how far will it travel before the battery runs out ?" and "how long does it take to recharge the batteries ?"

Electric Vehicle Range

EV buyers and operators may wish to compare vehicle travel distance range.

Range will be affected by vehicle body design and aerodynamics, battery capacity, vehicle loading, thermal management and electrical loads. UN/ECE regulation 101 compares electrical energy consumption based on Watt Hours / Kilometer (Wh/km)

Gross Vehicle Weight (GVW)

GVW constitutes the combined weight of vehicle and load. The weight of the vehicle body may be reduced by using high performance structural materials such as alloys and composites.

User demands from electric vehicles may be dictated by average journey distance and travelling time.

Recharge time depends on the size and type of battery, vehicle weight and load affected by driving style, existing charge level of battery, and electrical supply charging current availability from static battery charge points.

Electrically powered vehicles can be linked to telematics systems for fleet management. Sophisticated electrical current control of motor during driving and generator charging of battery ensures maximum range.

Commercial vehicle range is reduced as load is increased.

Main Powertrain Components of EV

Rotating Electric Machines

Rotating electric machines fall in to the classification of either motors or generators, both using magnetic fields and comprising a stationary component (stator) and a rotating component (rotor). An electric motor is supplied high current and voltage to create high rotary torque output.
Electric motors (E-motors) use electrical energy (Watts) to create rotating mechanical force (torque) in comparison to generators which use rotating mechanical force (torque) to create electrical energy (Watts).

Several designs of EV motor exist. Electric motors use magnetic fields to enable rotation.
The magnetic field used will be either permanent (permanent magnets) or temporarily created by electromagnetism.

Electric motor efficiency (%)) = ( Output power (kw) / Input power (kW) ) x 100

Permanent Magnet Electric Motors

A Permanent Magnet Synchronous Machine (PMSM) uses rare earth magnets.
Motor torque output is measured in either kilowatts, Newton Metres, or Horsepower.
A generic electric motor torque output graph generally shows a constant increase in power as revolutions per minute (rpm) speed increases.

Inductive Magnet-free Electric Motors

Seperately Excited Synchronous Machines (SESM) and Inductive-Excited Synchronous Motors (I2SM) use Alternatinc electrical current (AC) to build up electro-magnetic field in the rotor.

SESM uses brushes and slip rings to transfer electrical current to the rotor. Disadvantage of SESM is brush and slip ring mechanical wear and losses due to friction.

ZF I2SM and Mahle magnet free motor technology uses brushless motor design increasing sustainability.

EV Inverter

An inverter changes the characteristics of electric current from direct current (dc) to alternating current (ac).
Microcontrol of variable current frequency allows the inverter to control the speed of EV electric motors.
Some of the inverter input electrical power energy is lost as heat reducing output efficiency therefore temperature control is imprtant.

Vehicle Control Unit (VCU)

The VCU accepts driver input signals and processes to give outputs

DC-DC battery charger

Function of a DC-DC battery charger is to control charging current from a dc power supply to a second battery. A secondary function of the DC-DC converter enables control module low voltage (LV) power supplies to be maintained when the 12v battery is in a low state of charge (SOC)

Fuses

Fuses form a safety device to disconnect electrical power in the event of a fault.

Cabling

High voltage (HV) vehicle electrical cabling is colour coded Orange for easy identification

Battery Management System (BMS)

The BMS module allows monitoring of individual battery cells to optimise battery charging for peak power and efficiency.

EV Charging Port Connection

EV electrical connection to allow battery charging from a fixed power supply eg. Mains power source.

A wide range of vehicles offer electromobility

Electric Cycles

Electric Motorcycles

There is a whole range of electric motorcycles on the market from electric mopeds through to the worlds fastest production electric motorcycle, the Lightning LS218 , capable of zapping around at speeds of 200 mph plus.
Electric Motorcycle Specifications quote travelling distance range of anything between 60 and 400 miles on a full charge.

Typical electric motorcycles may be capable of 0-60 in 3.0 seconds whilst offering around 150 miles range on a single 60 minute fast charge.

Mobility vehicles for disabled

Electric vehicles for disabled persons require design to be accessibile, easy to use with restricted mobility ,portable, with ease of battery charging

Electric Cars

Many manufacturers have introduced a range of electric cars. Most EV car architecture uses 400v platforms.

Electric Vans & Light Commercial Vehicles

Electric vans have Small Medium Enterprise (SME) business applications for fleet transport use offering cost advantages over ICE vans. Much research has been carried out in to electric vans by stakeholders such as energy companies for example, UK Power Networks in the "White Van Plan".

Electric Trucks & Heavy Commercial Vehicles

Electric HGV trucks offer low noise benefits for example Dennis Eagle's electric waste collection vehicle combines low emissions with telematics technology to enhance fleet management. Low noise operation can be a key factor for utility vehicles operating in urban areas.

Good sized vehicle body roofs offer space to utilise the potential of solar panels.

Commercial vehicle electrical architecture often uses higher voltage 800v to 1200v platforms.

Electric Buses

Electric powered public transport has been a common sight in cities using tram networks. From electric minibuses to electric luxury coaches. There is an extensive list of manufacturers of electric buses..

Electric Tractors and Groundcare Machinery

The agricultural industry offers huge potential to exploit electric vehicle technologies to reduce emissions, and integrate precision management systems. Kinetic energy could be recovered from power take off shaft rotational braking as well as vehicle speed.

From the electric garden mower to innovate diy conversion of groundcare machinery. The horticultural industry is embracing green energy due to low vibration and convenience.

John Deere has pioneered the development of its electric SESAM tractor model.

Key features of electric tractors and groundcare machinery :

  • Less Vibration
  • Quieter working environment for machinery operators increasing comfort
  • Regenerative braking can slow rotational speeds
  • Variable speed and directional control
  • Consideration should be given to environmental design of machinery including insulation resistance and corrosion protection.

    Electric Construction Plant

    Electric excavator ranges are being developed by manufacturers such as JCB offering many benefits.

    Zero emissions mini excavators could be used inside buildings or underground for construction and demolition work.
    Reduced noise could extend contractor working hours in urban environments.

    Photovoltaic Solar panel arrays provide an income opportunity for land owners but care must be taken to avoid removing land from food production use.

    Electric Forklifts

    Electric forklifts have been in use for many years. Electric forklifts have an onboard battery pack normally recharged by plugging in to a mains supply whilst the truck is out of use. Traction motors are used to provide drive and hydraulic power. Zero emissions and low noise benefits for factory environments.

    Electric Vehicle Types

    Hybrid Electric Vehicles HEV

    Hybrid electric vehicles are complex and may have both low (12v, 24v, 42v) and high voltage battery systems, an internal combustion engine, combined generator / battery powered electric motor, and driveline consisting of either single clutch (mild hybrid) or multiple clutches (strong hybrid), and automatic transmission with mechatronic or hydrostatic actuation providing controlled torque output.
    The engine provides mechanical power to move the vehicle.
    The batteries store energy to power an electric motor so that short journeys can be made under electrical power. The battery does not have an external charging source on HEV models.

    during braking, a generator recharges batteries. Clutch packs can disconnect the engine to remove engine braking and allow kinetic energy to be used to regenerate batteries.

    HEV's offer the flexibility of running on fuel , only electrical power or a combination of both.

    Hydrogen Fuel Cell Elecric Vehicle

    Hydrogen fuel cells offer rapid refuelling and an alternative to batteries as a power source by producing direct current electricity from the chemical process of electrolysis between Cathode (-ve) and Anode (+ve) through a liquid or solid electrolyte.
    The Hydrogen fuel cell utilises a Proton Exchange Membrane (PEM) as a solid electrolyte, used to combine Hydrogen and Oxygen to form Water.

    Temperature changes can cause a problem. Hydrogen must be stored at high pressure. An Inverter is required to change electrical output from DC to AC for powering AC electric motors. Main current disadvantage is cost of production of the fuel cell.

    Monday 13th August 2018 : The University of Glasgow claims development of a "flow battery system" that increases energy storage and can cut charging times to seconds and store energy as Hydrogen gas or Electricity for use in hybrid vehicles.

    Plug in Hybrid Electric Vehicles (PHEV)

    PHEV's have both an engine, generator and electric motor drive, and automatic gearbox.
    PHEV Batteries can also be recharged from an external charging point for example from a special charging outlet wired to domestic mains supply.
    PHEV batteries can be recharged by engine driven generator or by regenerative braking.

    Plug in Electric Vehicles (PEV) Battery Electric Vehicle (BEV)

    Purely electric vehicles have no combustion engine therefore offer comfort with low noise and reduced maintenance costs. Power source is large, high voltage batteries supplying an electric motor with output via final drive or individual electric wheel motors. A clutch and gearbox is usually absent with forward and reverse being controlled electrically. Batteries are recharged by an external power source (mains) or by regenerative braking. AC from the alternator generator is rectified to DC to charge batteries by an inverter.
    Battery voltage is changed from DC to AC by the inverter to power the motor. Benefits from low maintenance costs due to no engine oil changes, no gearbox, no clutch. High Voltage Cables are identified by orange insulation.

    Extended Range Electric Vehicles (EREV)

    An engine driven generator provides additional battery charging to extend driving range. Drive is electric. (GM Chevrolet Volt / Ampera)

    Electric Vehicle Batteries

    battery cell symbol

    The vehicle battery is an electrochemical storage device providing a reservoir of electrical energy.

    A battery pack is made up of a number of galvanic cells consisting of
    The Anode (+ve plate) electrode
    The Cathode (-ve plate) electrode
    The Electrolyte

    Electrons flow from one electrode,through the electrolyte, on to the other electrode, during charge and discharge cycles.
    Electrolysis or Electron flow is termed Current (I) and is measured in Amps(A) creating a potential difference (p.d) in Volts across batttery cell terminals.

    Battery pack voltage is increased by linking battery cells in series. Battery pack current is increased by linking battery cells in parallel.

    Individual battery cells may have different states of charge (SOC) so cell balancing may be required to get optimum battery performance, this is done by control of charging done by a battery management system (BMS).

    Battery level guages measure Depth of Charge (DOH), State of Health (SOH), and State of Charge (SoC) in Coulombs or as a percentage. Instrumentation drift can occur over a period of time as equipment deteriorates. Inaccurate battery guage readings may require periodic recalibration of instrumentation and temperature correction.


    Electric vehicles may have both a low voltage lead-acid battery and a high voltage battery pack.
    The biggest problem with electric vehicles is the weight of the batteries (kg) which form part of the vehicle load and how to store enough energy (Joules) in the batteries to provide sufficient power (Watts) to run motors for long journey times (hrs). The energy provided from electric vehicle batteries can be compared to other fuels by energy density which is much lower for batteries using present technology than other fuels such as petroleum. Additional electrical loads such as lighting, electric steering, cabin temperature control, and entertainment systems will consume battery power reducing range.
    Higher voltage = faster charging times ; Higher voltage is available from 3 phase power supplies

    Thermal runaway : Temperature control of batteries can also be problematic especially in hot climates or at freezing temperatures.
    Battery cooling systems such as immersion cooling have been developed to enable faster charging and minimise fire risk.

    Lithium Ion is commonly used for vehicle batteries.

    Electric Vehicle Battery Charging

    Where can Electric Vehicles be recharged from ? and How long does battery charging take?

    Electric vehicle batteries can be charged from an external fixed installation (A.C. Mains, D.C. Supply network, or Generator) and to an extent by regenerative braking during driving.

    Battery capacity is proportional to time required to charge.
    Bigger batteries take longer to charge.
    Electric vehicle batteries can be charged from a domestic 16 amp supply via special charging point.
    Electric vehicle charging outlets have communication with onboard vehicle systems for battery management and climate control.
    Higher voltage (electrical pressure) allows more current flow (Amps) resulting in faster charging times.
    Fast charging at higher voltage from 3 phase industrial supplies can be accomplished in shorter periods of time using dedicated equipment to achieve around 80% SOC within rapid charging times of 30 minutes.

    Battery Replacement

    Replacement of the 12 volt vehicle battery is likely to require reset, battery registration, and calibration of the battery management system (BMS) using specialist vehicle diagnostic equipment to configure correct parameters.

    Replacement of the traction battery pack will require specialised lifting equipment.

    Super Capacitors

    Capacitors offer potential for rapid charge and discharge of electrical energy therefore Supercapacitors offer a potential solution to rapid charging of EVs.
    Advanced materials such as Graphene may make the low cost construction of super capacitors possible eventually superceding existing battery technology.

    Electric vehicle charging points

    A network of electric vehicle charging points is already in place across the UK. Many applications (apps) are available for mobile phones to show local EV charge point locations.
    Long journey route planning may need to take account of charge point location.

    Electric vehicle batteries can be recharged from the existing UK 230v domestic supply using applicable charger , this takes around 8 hours (source: Nissan website).

    Electric Vehicle Supply Charge Point Types

    Electric vehicles may be charged via various charging modes depending on availability and type of power supplies, cable, and connectors:

    Mode 1 : Maximun 16A

    Mode 1 Uses a charging lead from domestic 230v single phase supply. Typical vehicle charging time around 8 hours to theoretical 80% charge (domestic supply without communication).
    3 pin UK domestic plug BS1363 - 230v AC supply

    Mode 2 : Maximum 32A

    Typical vehicle charging time around 3 hours to theoretical 80% charge.
    IEC 60309 (BS 4343) Industrial Blue round 3 pin connector plug 230v AC Supply

    Mode 3 : Maximum 63A

    from dedicated supply point with charger to vehicle communication : Typical vehicle charging time around 1 hour to theoretical 80% charge. (Communication with vehicle)

    Mode 4: 400A

    from dedicated charge station with charger to vehicle communication.

    Vehicle side charging input -Inlet


    CHAdeMO - Japanese Electric Vehicles - DC
    CCS - Combined Charging System - European Electric Vehicles - DC

    Type 1 - Electric Vehicles - American SAE J1772 ( 5 Pin Plug) - AC
    Applications include :
    Chevrolet Volt - Citroen CZero - Ford Focus - Mitsubishi - Nissan Leaf - Peugeot Ion - Renault Fluence / Kangoo -Toyota Prius - Vauxhall Ampera

    Type 2 Mennekes IEC 62196 - 2 ( 7 Pin Plug : Has 3 large pins for main power and two communications pins plus two other.) - European Electric Vehicles AC
    Tesla type 2

    Wireless vehicle chargeing

    Innovative systems for wireless power transfer to electric vehicles (SAE J2954) are being researched and developed by some companies which will reshape vehicle transport.

    Electric vehicle charge point installation

    Qualified electrical installation of fixed EV charging points is required by law to meet regulations.

    UK Government encourages installation of electric vehicle charging points with a range of grant schemes.
    see UK OLEV Electric Vehicle Homecharge Scheme.

    The IET publishes a Code of Practice for Electric Vehicle Charging Equipment Installation book.

    How much does it cost to recharge the battery ?

    Charging cost will depend on battery charge capacity , level, source and cost of energy supplied.

    National Grid

    A network of fixed EV charging points is connected to the National grid.

    Savings may be made at off peak rates. Alternative energy sources may reduce cost. Smart metering devices and battery charge controllers may also reduce long term cost.

    Off Grid

    Off-grid installations include stand alone generators and photovoltaic solar panel charging systems.

    Regenerative Braking

    Regenerative braking utilises the similarity between a D.C. motor and D.C. generator (dynamo) to return electrical current back to the supply battery.

    To generate electricity by electromagnetic induction requires a magnetic field , and rotary motion of a wound rotor housed, in a stator. Torque is required to turn the rotor shaft whilst power is generated.
    Regenerative braking uses a generator fitted to the driveline to slow down the vehicle.
    Regenerative braking was commonly used on commercial vehicles (retarder) as a way to make the brake friction linings last longer by absorbing momentum and kinetic energy from the vehicle driveline which would otherwise be lost as heat.

    Rheostatic braking using resistors offers an alternative to regenerative braking and is used on electric trains (source: http://www.railway-technical.com).
    Braking generates heat which could be channelled to provide vehicle heating.

    Electric Motors for Vehicles

    There are many designs of both Alternating Current (AC) and Direct Current (DC) electric motors used in vehicles. Electric motors can be used in transport, agricultural, plant and machinery applications to drive hydraulic systems.

    Electric motors work on magnetic principles, by passing electrical current through wires wound in coils (windings) creating magnetic fields. This also produces heat.
    A motor consists of a Stator (static magnetic field) and a Rotor (rotating magnetic field).

    Reverse Gear : The direction of rotation of a DC motor may be reversed by controlling (switching) the direction of current flow and resulting magnetic fields, through stator or rotor armature.

    Torque load affects motor temperature and electrical current consumed and is proportional to load. Environmental climate also affects motor temperature and need for cooling. Overheating an electric motor can cause insulation to deteriorate and soldered joints to melt. Motor temperature control increases lifespan and safety.

    Electric vehicles can accelerate quickly and smoothly providing sufficient current and voltage is supplied and controlled.

    Current affects Torque and heat losses : Voltage affects speed : Reduced battery voltage and current will slow motor speed and output.

    Transistors can operate as both switches and amplifiers. therefore electric motor control circuits can be switched on or off with speed and torque control by utilising IGBT (insulated Gate Bipolar Transistors) (which are heavy duty transistors) and Thyristors in motor control circuit design.

    D.C Motors with commutators and carbon brushes can be subject to arcing, carbon brushes sticking in brush holders , and subsequent commutator damage. have advantages because no carbon brushes to wear out therefore lower servicing costs and increased lifespan.

    The design of motors is developing and offering compact size combined with reduced wear and liquid cooling. Brushless electronically controlled motors consisting of wound stator coils (phase windings), position sensors, and a permanent magnet rotor have advantages because increased control is possible together with no carbon brushes to wear out therefore lower servicing costs and increased lifespan.

    OTHER THINGS TO CONSIDER

    Manufacturers Warranty

    Manufacturers warranties may rely on the correct vehicle maintenance and charging of the vehicle battery. Periodic software updates may be required to validate insurance and warranty. Battery packs may have warranty against failure but can nevertheless degrade over time, requiring expensive replacement.

    Servicing and repair of electric vehicles

    Electric vehicles contain stored energy introducing hidden risks such as Arc flash and unexpected movement.

    Electric Vehicle (EV) Training Courses

    Technicians servicing electric vehicles require specialist training & qualification to understand and work on powertrain systems fitted to electric vehicles presenting dangers of electric shock and high voltage (HV).
    Technicians must follow manufacturers service procedures, HSE guidance and approved codes of practice.

    Drivers and operators of electric vehicles are also likely to require specialist safety training

    Emergency Services personnel may require specialist EV training to deal with critical situations where danger of HV electric shock is present.

    EV Garage Equipment &tools


    Fleet workshops, garages and MoT test stations equipped for servicing and maintenance of traditionally powered internal combustion and compression ignition engine (ICE) vehicles, will require additional investment in specialist equipment such as high voltage insulated tools and ppe, warning signage and barriers, and training to service electrically powered vehicles increasing costs.

    EV Recruitment

    Many companies seek to recruit trained electric vehicle technicians, autoelectricians, engineers and consultants. Research and development of electric vehicle technologies is a growing industry attracting government and innovtion funding.

    Legal aspects of Electric Vehicles

    The legal aspects of Electric Vehicles are extensive. Key points relate to Contract Law, Consumer Rights, Manufacturer's liability, Construction&Use, Intellectual property, Legislation, and of course, emissions.
    Drivers data storage has implications under data protection.

    Vehicle Safety

    Electric vehicles must have type approval and meet similar safety standards to standard vehicles.

    Electric vehicle chargers must incorporate an overcurrent protective device (fuse / circuit breaker) in each live conductor.

    Health and Safety executive provides guidance on electric and hybrid vehicle safety.

    Electricity at Work Regulations 1989 may apply.

    The Automated and Electric Vehicles Act 2018 c.18 s4.4 has particular references to safety critical software updates and its effect on liability of the vehicle insurer.

    Crash detection by safety restraint airbag systems may be linked to provide electrical isolation in the event of an impact.

    Reduced vehicle noise can affect other road users who may not hear the approach of a low noise vehicle.

    Danger of Electric Shock, Burns and Explosions from High Voltages. Danger of Arc Flash.

    Specialist training is required for persons dealing with electric vehicles including maintenance, emergency, and breakdown recovery personnel.

    Vehicle Recycling

    End of Life Electric Vehicles introduce specialist waste disposal requirements for items such as batteries. Producers, manufacturers and importers of vehicles are responsible for compliance with ELV legislation which is policed in the UK by DEFRA. Waste Electrical and Electronic Equipment (WEEE) Regulations may also apply.

    A huge quantity of batteries will be produced by scrapping electric vehicles .There is an emerging market for ELV secondhand battery packs to be used for domestic energy storage from PV solar panel , Windpower , and alternative off grid energy sources. High capacity battery packs are also in demand for use on vans used for mobile businesses such as catering. The Lithium taken from batteries could be used to produce greases.

    Factors affecting efficiency of electric vehicles

    Design and prototype development costs of both vehicles and charging network.

    Cost of production , tooling, marketing , equipping the aftermarket, technical training.

    Batteries : Weight of batteries : Bigger batteries = more range but are heavier so more power is used to move a greater load. Battery lifespan

    Recycling costs : Some batteries may be classified as hazardous waste.

    Developing Ideas

    A few developing ideas:

    Feasability of any idea is questionable when engineers examine ideas;

    Could a ground source heat pump be combined with traditional boiler to produce a steam powered generator for battery charging. The charged battery could then be used for domestic and transport energy supply.

    Could food waste be processed in biodigester to provide methane for fuel to burn to heat water to steam for generator to batteries to transport.

    Could a Tesla coil with electronic interference suppression be used for wireless battery charging.

    Could vehicle heating be provided by ducting air over resistor packs to use the heat discharged during regenerative braking ?

    Could solar panels be built in to vehicle body components eg the vehicle roof to allow additional battery charging ?

    Robotic vehicles

    New developments in electric vehicle technology allow manufacturers to go one step further, literally, with electric vehicles that have legs which can walk over rugged ground. Of course some of this new technology has been around a few years already in construction and agricultural industries where equipment manufacturers have used jack legs to raaise machines out of the mud.

    Some International & UK Legislation applicable to Electric Vehicles

    This list is by no means comprehensive:

    United Nations ECE R100 revision 3: Uniform provisions concerning the approval of vehicles with regard to specifci requirements for the electric powertrain.

    Automated and Electric Vehicles Act 2018 c.18

    Road Traffic Act

    Vehicle Type Approval

    Directive 2000/53/EC : End of life vehicles

    Electricity at Work Regulations 1989

    HSE Guidance note GS38

    The Waste Batteries and Accumulators Regulations 2009

    Bibliography and useful links

    1. 'The story behind the horseless carriage' viewed online at https://web.archive.org/web/20120621030141/https://www.gm.ca/inm/gmcanada/english/about/OverviewHist/hist_auto.html

    2. 'Office for Zero Emission Vehicles' viewed online at https://www.gov.uk/government/organisations/office-for-zero-emission-vehicles accessed 14th March 2023.

    BS EN ISO17409 : 2015

    BS EN ISO17409 : 2017

    Lu,J.,and Hossain,J.,Vehicle-to-Grid: Linking Electrc Vehicles to the Smart Grid. 1st edition, Stevenage,UK. The Institute of Engineering and Technology.

    Wikipedia : Patents of Nikola Tesla

    University of Glasgow : "Liquid battery could lead to flexible energy storage"

    Waste Elecctronic and Electrical Equipment Regulations, 2013.

    The Railway Technical Website : Electric Traction Control

    The Telegraph : "How does a fuel cell car work and should I buy a hydrogen car?"

    Fuel Cells

    Accelerating proton-coupled electron transfer of metal hydrides in catalyst model reactions

    Electric and Hybrid Vehicles

    Rahman,K et al,.Design and Performance of Electrical Propulsion System of Extended Range Electric Vehicle (EREV) Chevrolet Volt

    UN/ECE regulation 101

    Google Waymo : Self driving car

    Understanding Tesla Lithium Ion Batteries

    OLEV - Office for Low Emission Vehicles - lots of information here about electric vehicle charging points.

    The Institute of the Motor Industry offers a range of education about electric vehicles.

    Ricardo

    Diy Electric Garden Tractor

    JCB Electric Excavator

    Battery Info

    Does the battery fuel guage lie?

    HSE guidance note GS38 : Electrical test equipment for use on low voltage electrical systems

    Electronics tutorial: Insulated Gate Bipolar Transistors

    Dealing with waste lithium batteries

    Johnson Matthey battery systems : How cells work

    Driveline simulation software

    Wikipedia: Introduction to energy density

    The basics of EC motors

    IEC Standards

    Electric vehicle wireless charging

    HSE Magazine : Hazard of Electric Arc Flash

    ZF

    Engineering.com electric vehicle article viewed online 8th June 2019.

    Harley Davidson Livewire one motorcycle viewed online March 2023

    Magnet-free Electric Motors: How do they really work? viewed online 25May2024 at https://youtube.com Ultiem tech channel

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