Electric Vehicle Technology Explained

James Larminie, John Lowry

• Editore: Wiley
• Anno: 2012
• ISBN:
  9781118361122
• Edizione: 2
• Argomento: Technology & Engineering
• Categoria: Power Resources

Fully updated throughout, Electric Vehicle Technology, Second Edition, is a complete guide to the principles, design and applications of electric vehicle technology. Including all the latest advances, it presents clear and comprehensive coverage of the major aspects of electric vehicle development and offers an engineering-based evaluation of electric motor scooters, cars, buses and trains.

This new edition includes:

• important new chapters on types of electric vehicles, including pickup and linear motors, overall efficiencies and energy consumption, and power generation, particularly for zero carbon emissions
• expanded chapters updating the latest types of EV, types of batteries, battery technology and other rechargeable devices, fuel cells, hydrogen supply, controllers, EV modeling, ancillary system design, and EV and the environment
• brand new practical examples and case studies illustrating how electric vehicles can be used to substantially reduce carbon emissions and cut down reliance on fossil fuels
• futuristic concept models, electric and high-speed trains and developments in magnetic levitation and linear motors
• an examination of EV efficiencies, energy consumption and sustainable power generation.

MATLAB® examples can be found on the companion website www.wiley.com/go/electricvehicle2e

Explaining the underpinning science and technology, this book is essential for practicing electrical, automotive, power, control and instrumentation engineers working in EV research and development. It is also a valuable reference for academics and students in automotive, mechanical, power and electrical engineering.

Chapter 1

Introduction

Electric vehicles are becoming increasingly important as not only do they reduce noise and pollution, but also they can be used to reduce the dependence of transport on oil—providing that the power is generated from fuels other than oil. Electric vehicles can also be used to reduce carbon emissions. Production of zero release of carbon dioxide requires that the energy for electric vehicles is produced from non-fossil-fuel sources such as nuclear and alternative energy.

The worst scenario is that we have only 40 years supply of oil left at current usage rates. In practice, of course, increasing scarcity will result in huge price rises and eventually the use of oil and other fossil fuels will not be economically viable, hence oil will be conserved as usage will decrease. Oil can also be produced from other fossil fuels such as coal. Traditionally oil produced in this way was considered to be around 10% more expensive, but with current oil prices production from coal is starting to become economic. Coal is more abundant than oil and there is in excess of 100 years of coal left, though it is still a finite resource.

Increasing worries about global warming continue. Global warming is blamed on the release of carbon dioxide when fossil fuels are burnt and it is believed to give rise to a myriad of problems including climate change and rising sea levels which could destroy many of the world's coastal cities.

Electric trains are well developed and are widely used whereas road transport has only just reached the point where vehicle manufacturers are starting to produce electric cars in quantity. Whereas small electric vehicles used in niche markets, such as electric bicycles, invalid carriages and golf buggies, are widely used, electric road vehicles are not. Electric road vehicles have not enjoyed the enormous success of internal combustion (IC) engine vehicles, which normally have much longer ranges and are very easy to refuel.

It is important that the principles behind the design of electric vehicles and the relevant technological and environmental issues are thoroughly understood; these issues will be pursued in the following chapters.

1.1 A Brief History

1.1.1 Early Days

Electric motors developed following Michael Faraday's work in 1821. The first commutator-type direct current electric motor capable of turning machinery was invented by the British scientist William Sturgeon in 1832.

The first known electric locomotive was built in 1837 by the chemist Robert Davidson, and was by powered by non-rechargeable batteries. Davidson later built a larger locomotive which was exhibited at the Royal Scottish Society of Arts Exhibition in 1841. The first use of electrification on a main line was on a 4 mile (6.4 km) stretch of the Baltimore Belt Line in the USA in 1895. Figure 1.1 shows the locomotive.

Figure 1.1 Electric locomotive, 1895 (Source: http://en.wikipedia.org/wiki/Electric_locomotive)

Electric trams or trolley cars were first experimentally installed in St Petersburg, Russia, in 1880. The first regular electric tram service, the Gross-Lichterfelde Tramway, went into service in Lichterfelde, a suburb of Berlin, Germany, and was produced by Siemens & Halske AG, in May 1881.

The first electric street tramway in Britain, the Blackpool Tramway, was opened on 29 September 1885. By the start of the First World War trams were used in many cities throughout the world. Figure 1.2 shows a tram in London in 1910.

Figure 1.2 Double-decker tram in London, 1910 (Source: http://en.wikipedia.org/wiki/Tram)

The trolleybus dates back to 29 April 1882, when Dr Ernst Werner ran his bus in a Berlin suburb. In 1901 the world's first passenger-carrying trolleybus operated at Bielathal, near Dresden, in Germany. In Britain, trolleybuses were first put into service in Leeds and Bradford in 1911.

Half a century was to elapse after the first electric vehicles before batteries had developed sufficiently to be used in commercial free-ranging electric vehicles. An early electric vehicle, a Baker Runabout, made in the USA and imported into Germany by the founder of Varta Batteries, is illustrated in Figure 1.3. Figure 1.4 shows the first car to exceed the ‘mile a minute’ speed (60 mph; 97 kph) when the Belgian racing diver Camille Jenatzy, driving the electric vehicle known as ‘La Jamais Contente’,¹ set a new land speed record of 106 kph (65.9 mph) making this the first car to exceed 100 kph.

Figure 1.3 Baker Runabout in 1893 (Reproduced with permission from Varta)

Figure 1.4 Camille Jenatzy's ‘La Jamais Contente’. This electric car held the world land speed record in 1899, and was the first vehicle to exceed both 60 lmph and 100 kph

By the end of the nineteenth century, with mass production of rechargeable batteries, electric vehicles became fairly widely used.

Private cars, though rare, were quite likely to be electric, as were other vehicles such as taxis. An electric New York taxi from about 1901 with Lilly Langtree, the actress and mistress of Edward VII, alongside, is illustrated in Figure 1.5.

Figure 1.5 New York taxi cab in about 1901, a battery electric vehicle (The lady in the picture is Lily Langtree, actress and mistress of King Edward VIII)

At the start of the twentieth century, electric road vehicles must have looked a strong contender for future road transport. Indeed, if performance was required, the electric cars were preferred to their IC or steam-powered rivals.

The electric vehicle was relatively reliable and started instantly, whereas IC engine vehicles were at the time unreliable, smelly and needed to be manually cranked to start. The other main contender, the steam engine vehicle, needed lighting and the thermal efficiency of the engine was relatively low.

By the 1920s several hundred thousand electric vehicles had been produced for use as cars, vans, taxis, delivery vehicles and buses. However, despite the promise of these early electric vehicles, once cheap oil was widely available and the self-starter for the IC engine (invented in 1911) had arrived, the IC engine proved a more attractive option for powering vehicles. Ironically, the main market for rechargeable batteries has since been for starting IC engines.

The reasons for the greater success to date of IC engine vehicles are easily understood when one compares the specific energy of petroleum fuel with that of batteries. The specific energy² of fuels for IC engines varies, but is around 9000 Wh kg⁻¹, whereas the specific energy of a lead acid battery is around 30 Wh kg⁻¹. Once the efficiency of the IC engine, gearbox and transmission (typically around 20%) for a petrol engine is accounted for, this means that 1800 Wh kg⁻¹ of useful energy (at the gearbox shaft) can be obtained from petrol. With an electric motor efficiency of 90% only 27 Wh kg⁻¹ of useful energy (at the motor shaft) can be obtained from a lead acid battery. To illustrate the point further, 4.5 l (1 gal)³ of petrol with a mass of around 4 kg will give a typical motor car a range of 50 km. To store the same amount of useful electrical energy requires a lead acid battery with a mass of about 270 kg. To double the energy storage and hence the range of the petrol engine vehicle requires storage for a further 4.5 l of fuel with a mass of around 4 kg only, whereas to do the same with a lead acid battery vehicle requires an additional battery mass of about 270 kg. This is illustrated i...