Recognize the importance of national and European Regulations in relation to renewable technologies in the construction and automotive industries.
Discuss environmentally related technologies and materials that are fundamental in a range of industries including construction, structural mechanics, automotive and environmental operations.
Discuss environmental issues related to resource provision and consumption necessary for the manufacture of engineered products, and analyse potential for the application of alternative energy sources.
Call for Papers - African Journal of Biological Sciences, E-ISSN: 2663-2187, ...
Automotive Hybrid Technology Development - Past, Present and Future
1. Faculty of Science, Engineering and Computing
School of Mechanical and Aerospace Engineering
Assignment title:
Task 2
Automotive Hybrid Technology
Development - Past, Present and Future
Module: Green Engineering (Automotive option)
Setter: Dr R Rayner
Deadline: 15 May 2017
Name: SHIH-CHENG TUNG
KU number: K1617281
Course: MSc Automotive Engineering
2. Abstract
The automotive industry has been developed for more than a hundred years that led
numerous relative developments to become the significant part in the world. In this
report, the conception of hybrid is investigated through different aspects such as
PEST analysis. The partial history of hybrid development is introduced which
assistance to understand the previous technologies applied on the prototypes. In
technology side, the architectures and drivetrains of hybrid vehicles are illustrated in
detail including micro, mild, full hybrid system, series, parallel and power split.
Through the comparisons of various designs, the barriers and motivations on each
state of hybrid technology could be identified. In addition, an evaluation is presented
to discuss the possible solutions and development of automotive hybrid technology
in the future.
Key words:
Hybrid electric vehicle, hybrid history, future of hybrid, analysis of hybrid
3. Contents
1. Introduction
a. Hybrid Electric Vehicle Architectures
b. Hybrid Electric Vehicle Drivetrain configuration
2. Methodology and methods
3. Literature review
a. Hybrid Electric Vehicle Architectures
b. Hybrid Electric Vehicle Drivetrain configuration
c. Levels of hybridisation
d. History of hybrid
4. Results and analysis
a. Political factors
b. Economic factors
c. Social factors
d. Technologicalfactors
e. Analysis of hybrid architectures
f. Analysis of hybrid drivetrains
5. Evaluation and Conclusion
6. Bibliography
4. 1. Introduction
In recent decades, the issues of carbon emissions and energy consumption become
significant important due to the growth of automotive industry (Delprat et al., 2004).
The number of vehicles is increasing gradually as well as air pollutions and fuel
consumption. However, most of the countries have relative regulations to support the
developments of renewable technologies. In the automotive industry, the innovation
of the hybrid vehicle might be the turning point. Currently, there are numerous
designs of the hybrid vehicle in most of the automotive manufacturers. The electric
hybrid vehicles are came up with to reduce the global carbon emission and pollutions
as well as fuel consumption (Enang and Bannister, 2017). Since the hybrid vehicles
are invented for more than a hundred years, it combines varied power propulsion
system which could generate a higher efficiency. The collaboration of the internal
combustion engine and the electric motor consists a hybrid electric vehicle that
manages to different powertrains (TOYOTA, 2003). In addition, the battery stores the
regeneration of braking which is used to supply the operation of the electric motor.
The electric hybrid technologies are developed as various architectures and levels.
For example, there are three main types of hybrids such as series hybrids, parallel
hybrids, and series-parallel hybrids.
In order to resolve the hybrid technology from the early 20th Century, the motivations
and barriers of development are identified. Through the comparisons of each hybrid
designs’ detail, an organised analysis is presented. Moreover, the potential solutions
are predicted in the evaluation.
2. Methodologyand methods
In order to understand the conception of automotive hybrid technology, the research
methods adopted are significantly important. In this case, the general knowledge is
provided by the lectures and presentations of Engineering & Energy Efficiency
module (hybrid option). In addition, it is necessary to investigate the in-depth
information of hybrid technology. Thus, the secondary research include the history
from early 20th century and current technological developments, which offers the
comprehensive contents required. To present an analysis and evaluation clearly, the
literature surveys are explored and identified through different aspects in this report.
5. 3. Literaturereview
a. Hybrid Electric Vehicle Architectures
Hybrid electric vehicles are generally consisted by an internal combustion engine,
rechargeable battery, electric motor (generator) and hybrid controller. As traditional
vehicles, hybrid electric vehicles have conventional combustion engine that could be
mainly petrol or diesel engine. Nevertheless, there are other designs of propulsion
system such as fuel cell-electric, internal combustion engine-hydraulic and internal
combustion engine-pneumatic hybrid.
In terms of HEV, it needs a rechargeable battery to store or provide electricity. The
common rechargeable battery could be Lithium-ion (Li-ion) or Nickel metal hydride
(NiMH) battery which is composed of different cells. The electric motor drives the
wheels using electricity from the rechargeable battery. HEV also requires a
generator to transform mechanical energy into electricity, which is a similar structure
to the electric motor.
b. Hybrid Electric Vehicle Drivetrain configuration
Hybrid electric vehicles can be divided according to the drivetrain configurations.
There are three main types including series hybrids, parallel hybrids and series-
parallel (power-split) hybrids.
The parallel hybrid system has an electric motor and an ICE which are connected
with the transmission to the wheel axle (van Berkel et al., 2012). While the coupled
mechanism between two power sources could supply the torques jointly or
individually. The electric motor is also the generator in the parallel hybrid system for
recharging. In addition, the parallel hybrid system might be the most common type
which is utilised on HEV in 2016.
For the series hybrid system, the ICE does not have a direct connection to the drive
axle which means the electric motor is the only power source. However, the ICE
drives the generator to produce electricity which is stored in the rechargeable battery
to power up the electric motor. The electric transmission enables to substitute the
mechanical transmission in the series hybrid system so that could reduce the weight,
6. complexity, and noise (Pavan, 2014). Such a system as known as a range extender
because the range of vehicle driven by the electric motor can be increased. The
power-split hybrid or series-parallel hybrid system collaborates series as well as
parallel which could allow power paths to be mechanical or electrical depending on
the situation
c. Levels of hybridisation
Generally, there are three classifications including micro hybrids, mild hybrids and
full hybrids which are relevant to the degree of hybridisation. The different
classifications are allocated by levels of hybridisation.
The micro hybrids are a design to start and stop the engine during the traffic which
could reduce the fuel consumption and gas emissions. The stop-start system does
not provide assistance to propulsion, instead, it limits the idle rotation speed of the
ICE in 700-1000 revolutions per minute (RPM) automatically when starting the ICE
(Bitsche and Gutmann, 2004). In this way, the battery is able to supply the electricity
demand while the ICE is shut off (Bitsche and Gutmann, 2004). The simple structure
of the micro hybrid system and cheap cost cause it becomes popular in automotive
manufactures. In addition, the fuel consumption could be saved approximate 10 per
cent (Milnes, Deller and Hill, 2010). For instance, the Mercedes-Benz A-class, BMW
1 and 3 series and the Fiat 500.
The mild hybrids are utilised to produce the power assistance also include the stop-
start function. The ICE in mild hybrid system generates the primary power, while the
electric motor enhances the torque through the transmission to complement the ICE.
Due to the affordable cost and the acceptable weight, mild hybrids have smaller
battery and motor than full hybrids which could not propel the vehicle solely. In this
case, the electric motor is used to assist the lower torque of ICE when accelerating
or starting. Thus, the fuel consumption of mild hybrids could be saved about 20 per
cent (Milnes, Deller and Hill, 2010). Examples of mild hybrids on the markets are the
Mercedes-Benz S400 BlueHybrid, BMW 7 series, and the Honda Civic and Insight.
In terms of full hybrids, the most required components could be the same as mild
hybrids. However, the engine size is decreased due to the larger electric motor and
7. battery pack. The vehicle could supply a propulsion of the electric motor, the ICE or
both through the power-split transmission (Cao, Peng and He, 2016). For example,
Toyota’s Hybrid Synergy Drive adopts a planetary gear set as the transmission
components to allocate the portion of power (TOYOTA, 2017). Thus the full hybrid
system could achieve different power modes to increase the fuel efficiency running in
the city and the motorway. Although the weight and costs of full hybrids could be
higher than others, the fuel consumption could be saved approximate 40 per cent
(Milnes, Deller and Hill, 2010). Examples of full hybrids are the Honda CR-Z, Toyota
Prius and the Chevrolet Tahoe Hybrid.
Some electric hybrid vehicles could be considered as plug-in hybrids by requiring a
charge port and ability of pure electricity powered. It could be more beneficial for the
travelling in short distance. While the battery could supply sufficient electricity to
achieve the pure electric mode after charging the battery, there is no fuel
consumption by vehicle (Van Mierlo, Maggetto and Lataire, 2006). Examples of plug-
in hybrid electric vehicles are the Toyota Prius Plug-in, Chevy Volta and the Porsche
Panamera S E-hybrid.
d. History of hybrid
The developments of hybrid vehicles have been started near for over a hundred
years which plays an important role in the automotive industry. The history of hybrid
vehicles is almost as long as electric cars’ history as the developments of both
batteries and electric motors (Westbrook, 2001). In 1900, Ferdinand Porsche, one of
the first inventor of the hybrid car introduced a petrol-electric car Lohner-Porsche at
Paris Exposition (Høyer, 2008). A French company, Krieger, designed a hybrid
vehicle with front wheel drive and power steering in 1901 (Anderson and Anderson,
2005). The Krieger’s hybrid car included a series hybrid system which consisted of a
small petrol motor, an electric generator and two electric motors. Similarly, Henry
Pieper launched a hybrid vehicle which involved one electric motor and one small
petrol motor in 1905,
From 1901 to 1906, Milde Electric Car provided several hybrid models in American
which could apply electric motor as supplementary power or sole power source
(Anderson and Anderson, 2005). In the same period, another French manufacturer,
8. Jenatzy had a parallel hybrid vehicle developed which could run with collaboration or
individual of the electric motor and petrol engine (Høyer, 2008). As well as the
American Woods Motor, a parallel hybrid vehicle with the four-cylinder petrol engine
and mechanical transmission was produced in 1916 (Høyer, 2008). In 1914, there
was a series hybrid car manufacturer, Galt Motor in Canada. The hybrid car made by
Galt Motor had the potential to reach a top speed of 50 km per hour and fuel
consumption of 25 km per litre (Anderson and Anderson, 2005). In 1931, a 0.5
horsepower electric car was combined into hybrid cars (M. Sabri, Danapalasingam
and Rahmat, 2016). Besides, a series of hybrid design were applied on tanks by
Ferdinand Porsche during the World War Two. However, the conception of hybrid
did not be looked seriously at the moment due to the expensive cost. The market
acceptability was not as high as producer’s approximation. In addition, the hybrid
vehicle was not affordable as the petrol vehicle which led the development of the
hybrid vehicle to a temporary rest.
Lohner-Porsche Semper Vivus
Adapted from (Ernst, 2013)
1903 Krieger’s hybrid
Adapted from (Modernracer, 2004)
Henri Pieper's Hybrid Vehicle Patent
Application Adapted from (Berman, 2009)
Porsche's Elefant tank destroyer
Adapted from (Wikipedia, 2009)
9. Afterwards, several initiatives of the hybrid vehicle were came up with in the 1970s
due to the energy crisis (Høyer, 2008). The awareness of air pollution and climate
change were raised as well as sustainable technology. During 1960 to 1979, a hybrid
drivetrain was collaborated with a 1972 Skylark model of Buick by Victor Wouk. The
title of ‘godfather of the hybrid’ was given to Victor Wouk due to his contribution to
the hybrid technology (Wouk and Goodstein, 2004). The early 1990s could be
considered as the second era of hybrids that brought hybrid development into
another adventure. There were several models in 1990s including BMW 5 Series,
Volvo ECC. Differently, Volvo ECC has mounted a gas turbine engine for generating
electricity.
In 1993, the Clinton administration of America declared an initiative, Partnership for a
New Generation of Vehicles (PNGV), to encourage the manufacturers producing the
‘clean car’ with a goal of 25 km per litre for fuel consumption. Nevertheless, the
PNGV resulted in three prototypes of the hybrid vehicle and they were not presented
in the market (Anderson and Anderson, 2005). In 1997, an apparent conversion
happened with Toyota Prius on the Japanese market while Audi launched a first
hybrid model in Europe, Dou. Unfortunately, Audi interrupted the production of Duo
due to the unsuccessful sales volume and effect of the diesel engine (Høyer, 2008).
It was notable that Honda and Toyota introduced their hybrid car individually, Insight
and Prius to American automobile market in 1999 and 2000. Toyota Prius could be a
successful sample on both European and American markets, its second generation
also was awarded the Car of the Year.
Afterwards, more advanced designs of the hybrid were involved in manufacture
hybrid vehicles. The third generation of Audi Duo with a turbocharged diesel engine
was released in 1997 and it was the only European product in the market. Moreover,
Ford Escape was introduced as the first hybrid sport utility vehicle (SUV) in 2005
(Høyer, 2008). During 2006 to 2009, General Motor developed the Belted Alternator
Starter (BAS) hybrid system to utilise on Saturn Vue Green Line and Malibu Hybrid
models as a front wheel drive powertrain. While Lexus, Toyota and Nissan
introduced separately their hybrid cars, GS 450h, Camry Hybrid and Altima Hybrid
with Toyota’s technological patents.
10. In recent developments, first hybrid vehicle with liquefies petroleum gas (LPG)
engine and advanced lithium polymer (Li-Poly) battery pack, Elantra LPI, it was
presented by Hyundai in 2009 and qualified as a Super Ultra Low Emission Vehicle
(SULEV). In the same year, the Mercedes-Benz introduces S400 BlueHybrid which
is a first hybrid vehicle with a lithium-ion (Li-ion) battery pack adopted.
In 2010, Honda released CR-Z and Jazz Hybrid to U.S. and European markets,
while the Toyota Auris Hybrid is first mass-produced hybrid vehicle in Europe which
was built at Toyota Manufacturing UK Burnaston plant. Volkswagen introduced
Touareg Hybrid in 2010 and diesel-electric hybrid systems with Jetta, Golf Hybrid
and Passat sequentially whilst Lexus CT 200h, Hyundai Sonata Hybrid, Infinity M35
Hybrid and Kia Optima Hybrid were presented in the US. The Peugeot 3008 HYbrid4
became the first production diesel-electric in the world in 2012, meanwhile, the
Toyota Prius series were involved with Prius Alpha and Prius Aqua. In addition,
BMW 3 series Hybrid, BMW 5 Series ActiveHybrid, Ford C-Max Hybrid, Audi Q5
Hybrid, Acura ILX Hybrid and next generation of Ford Fusion Hybrid and Toyota
Camry Hybrid were released in 2012 as well.
Both Toyota and Honda introduced new models in 2013, the Toyota Corolla Axio,
Corolla Fielder and the Honda Vezel Hybrid, while Range Rover presented the
diesel-electric hybrid car. In 2013, the best-selling hybrid vehicle in the world is Prius
and its fourth generation was released in 2015.
11. 4. Analysis and Result
a. Political factors
Numerous countries including the Japan, US, Germany are urging the development
of hybrid technology to improve the environment. The ambitious of each country
cause the progress of international policies to deal with the climate change
(Gallagher and Muehlegger, 2011). Although Japan is the one of the main hybrid
manufactural countries, Europe establishes various incentives and regulation to stint
the emission of the automotive sector. For example, cars manufactured between
2012 and 2015 are restricted to meet the standard of 130gCO2 per kilometre in
Europe (Milnes, Deller and Hill, 2010). Moreover, a restriction of 95gCO2 per
kilometre for 2020 has been suggested by European Commission (Milnes, Deller
and Hill, 2010). As a result, the hybrid vehicles have the potential of growth under
the support of governments that assists to reduce carbon emission and fuel
consumption.
b. Economic factors
A J.P. Morgan’s study predicts that the sales of hybrid vehicles will be sold over 13
per cent of all vehicle sold (Cembalest, 2016). The stable growth of hybrid vehicles
could represent the acceptability and affordability of public. In addition, the fuel price
and development of hybrid technology could be the effective factors. Through the
popularisation of hybrid vehicles, both the technological and environmental aspects
would be improved in a short period. It is possible to save the costs of fuel and
maintenance (Offer et al., 2010).
c. Social factors
Due to the mass production of hybrid vehicles, the impacts of manufacture and
maintenance emerge. The process of making the electronic components involves
raw metal machining and material importing (Diamond, 2009). To deal with the
wasted heavy metals, it could take more energy which is the contrast to the
environmental protection (Granovskii, Dincer and Rosen, 2006). For maintenance,
the techniques for hybrid vehicles are different with convention vehicles. The high
12. voltage circuit in hybrid vehicles could be extremely hazardous, which needs specific
certificates to ensure the safety.
d. Technological factors
Recently, the battery packs fitted in hybrids are most NiMH due to the reasonable
performance and cost. According to a study, the power density of NiMH battery are
about volumetric 150 Wh/litre and gravimetric 70 Wh/kg, compare to Li-ion’s
volumetric 300 Wh/litre and gravimetric 120 Wh/kg, while the prices are €250-
€500/kWh for NiMH and €700-€1,400/kWh for Li-ion (Milnes, Deller and Hill, 2010).
Although the Li-ion battery pack has lighter weight and higher power density than
NiMH, the price of Li-ion is much more expensive than NiMH. In this case, the
revolution of battery and recharging methods effects both hybrid electric vehicles and
electric vehicles. As the technologies being mature gradually, the electric vehicle
could substitute the hybrid electric vehicle that reduces the emissions and noises
significantly (Romm, 2006).
e. Analysis of hybrid architectures
Series hybrid
Engine not coupled to wheels which can set up at efficient engine RPM
Simple mechanical drivetrain
Motors are more efficient than ICE during acceleration
Can run as pure EV
All power come from motors which could be limited by small motors
Energy wasted during conversion which means lessening efficiency
The heavy weight due to added components
Parallel hybrid
Less energy lost between engine and wheels
Instantaneous power could be supplied with revving ICE
Allowing smaller electrical system which means potential weight savings
Engine not always at efficient speed
Requiring a mechanical linkage between ICE and electric motor
13. Series-parallel (power split)
Combination of series hybrids and parallel hybrids
Multiple power operations
Complex transmission of power split mechanism
Higher weight and cost than others
f. Analysis of hybrid drivetrains
Micro hybrids
Micro hybrids could be applied on various vehicle easily due to the lower cost,
weight and volume.
The stop-start feature produces lower fuel consumption and emission during
the urban driving.
The fuel saving could be up to 10 per cent which is effective to the city driving.
The propulsion system is only supplied by the ICE.
Mild hybrids
Mild hybrids involve both the ICE and the electric motor in the propulsion
system.as well as the stop-start feature.
The electric motor produces the torque required to complement the ICE
during the accelerating.
The reasonable cost of mild hybrids is the main factor to become the largest
amount in hybrids.
Approximate 20 per cent fuel efficiency could be increased.
The electric motor and battery could be less powerful than the full hybrids.
Mostly, the electric motor could not propel the vehicle solely in mild hybrids.
Full hybrids
Full hybrids obtain the high-performance battery and electric motor that could
run as an electric vehicle.
The ICE could be downsized due to the assistance of the electric motor.
40 per cent of fuel economic could be improved by full hybrids.
A complex transmission is necessary to manage the multiple operations of
propulsion.
14. The technology requirements are the highest as well as costs.
Plug-in hybrids
Plug-in hybrids could deliver the highest fuel efficiency up to 40 per cent due
to the electric driving mode.
The battery installed could be smaller than the pure electric vehicle.
The charge port enables vehicles to be plugged into other electric grid.
Adapted from (CAAT, 2017)
5. Evaluation and Conclusion
The hybrid electric vehicles could obtain the superiorities from both the electric
vehicles and the conventional ICE vehicles. The ICE provides the primary propulsion
during the high-velocity driving, while the electric motor supplement the high torque
during the start from traffic. However, the costs and weight are the common barriers.
Hybrid technologies are explored continuously as part of sustainable development
that means the innovation of automotive industry could be potential. Due to the
electric vehicles are still restricted by the range, the researchers try to develop the
battery in higher power density. However, the expensive fund and long research
period cause the lower popularisation of the electric vehicle. Compare to electric
vehicles, the potentiality of hybrid vehicles could be higher in the future. As various
developments of the ICE and the battery are discovered to improve the efficiency
that not only benefits the conventional vehicles and electric vehicles also increase
the diversity of hybrid vehicles.
15. For example, the thermal efficiency of a petrol ICE is around 25 to 50 per cent which
means massive of energy is wasted. To recycle the heat wasted could be one of the
solutions to improve the efficiency of the hybrid vehicle through the energy
conversion. On the other hand, the weight of hybrid vehicle could be the significant
barrier which affects the energy consumption as well. For plug-in hybrid vehicles, the
capacity of battery could be smaller than others that could improve the
comprehensive performance by reducing vehicle weight. In addition, the charging
station could offer the extra power input through plugging the charger.
To conclude, the automotive hybrid technology has been developed over one
hundred years, different levels and configurations are explored through the
improvements. The previous knowledges provide a helpful foundation for evolution.
Certainly, the performance of the hybrid vehicle is enhanced gradually during the
innovation of material. In addition, the automotive industry attempt to optimise the
electric vehicles in the same time as well as the conventional ICE vehicles. However,
in the future, the breakthrough could benefit the automotive hybrid technology due to
the flexibility and
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