Electric Vehicles Paper Final

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NEW TECHNOLOGIES FOR VEHICLES
Breno Gomes1, Yago Pacheco2,
December 8, 2015
ABSTRACT

This work is about Supercapacitor, a visibly growing up technology in
terms of energy for vehicles as an alternative to fossil fuels. There is some
new good stuff in alternative energy, but supercapacitor stands out mainly in
determined cases. This work also has some examples of applications of
supercapacitors in vehicles that are already being used today, and what
expect for the future of this technology.
KEY WORDS
Electric Vehicle, Mazda, Volvo, Technology, Supercapacitor, Train, Bus, I-Eloop,
Ultracapacitor.
INTRODUCTION

What is “Supercapacitor”? Supercapacitors, also known as
ultracapacitors or double-layer capacitors, are capacitors with have high
capacitance. Supercapacitors have capacitance values between 100000 µF to
1000F and work usually with voltages between 1.2 to 3.8V.
Actually, supercapacitors were first noticed in 1957 by General Electric
engineers experimenting with devices using porous carbon electrode, but just
now the ultracapacitors are having their use growing up increasingly, mainly
in the recent years, because of the global call to reduce pollution, advances
in nanomaterials and the necessity of new methods of energy to substitute
the non-renewable energy today used in large scale
BATTERY X SUPERCAPACITOR

Different from batteries that rely on a chemical reaction, ultra capacitors
store energy in an electric field. This is the way that allow them to charge
and discharge much faster than batteries. The batteries lifetime is very
restricted by the chemical process, on the other side, supercapacitors can
survive a lot of charge and discharge cycles. Supercapacitors have also
almost no internal resistance, and it allowing them to work at efficiency up
to 98%. Supercapacitors also do not use harmful chemicals or toxic metals.
WHY TO USE SUPERCAPACITORS?
1 Department of Electrical Engineering, California State University, Long Beach, CA 90840, Phone: (562)
726-5371, Email: [email protected].
2 Department of Electrical Engineering, California State University, Long Beach, CA 90840, Phone: (562)
786-4543, Email: [email protected]

With so many different new technologies, why should we invest heavily in this
specific method? Today this technology is just starting, and it is applicable mainly in two
specifics cases: The start-stop and the regenerative braking systems.
The first one enable an engine to shut down when the car is sitting in a traffic or
when it comes to a stop at a light, for example. The ultracapacitors at this moment
provide a short burst of energy that restarts the motor.
Regenerative braking is more used today, the main idea is that the system should
capture the kinetic energy of a moving car during the braking that generally would be
lost and then release it again during the acceleration or in other systems, such as backup
power for sounds systems in the cars.
Supercapacitors are ideal for these two cases because: Supercapacitors deliver way
more power for weight than lithium-ion batteries; today the efficiency is up to 98%; they
are very tolerant of high temperatures; charge almost instantly; and for power discharges
below 15 secs, they are one of the cheapest technologies available today. It’s projected
that at least half of the new cars will be coming with these systems by 2022.

MAZDA AND I-ELOOP TECHNOLOGY

Figure 1: Mazda i-Eloop System
(http://www2.mazda.com/en/technology/env/i-eloop/)
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I-Eloop is the name of the technology used by Mazda in some of their cars.
This invention is a brake energy regeneration system which means it stores energy that
usually is wasted through heat by the brakes during a brake period.
I-Eloop process starts at the brake. When braking the alternator convert mechanical
energy into electricity and then it is quickly stored in the Electric Double Layer
Capacitor (Supercapacitor). After that a DC/DC converter the energy from 12 volts to 25
volts in order to transfer the electricity to a battery or use it in others systems.
Mazda claims that I-Eloop can save 10% of gas, a quantity that uses be spent
to produce electricity for lamps, audio system and climate control.

VOLVO

Figure 2: Number of electric car sales per year from 2008 to 2014 (http://www.ibtimes.com/globalelectric-car-market-about-43-all-electric-passenger-cars-were-bought-2014-say-1857670)

Volvo developed car parts that actually are not ordinary replacement pieces.
In fact, they are well designed supercapacitors made to replace body parts of the vehicle
and the battery. The new material is capable of store energy wasted during brake periods.
Some advantages of this kind of parts are they reduce the consumption through reducing
approximately 15% of the car’s weight from the roof, trunk, underhood and batterie and
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they are capable of store energy from braking. They are light because they are made by
carbon-fiber and the dielectric is fiberglass.
The disadvantages are the cost of the material, straightly related to the high
cost of carbon fiber. Another issue for this technology is the possibility of the car stop
working or catch fire due to a dent on any of the Carbon-fiber supercapacitor parts.
CAPACITOR BUS

Today, one of the most successful applications with supercapacitors is the known as
CapaBus that is a new form of an electric bus. It is an autonomous vehicle, in others
words, it runs without continuous overhead lines by using power stored in large onboard
supercapacitors. The supercapacitors are quickly recharged always that the bus stops at a
determined bus stop which has the recharger.
Some bus already runs in Shanghai since 2006. The buses should have very
predictable routes and need to stop regularly every 4.8km (3 miles) or less. This way the
quickly recharging is allowed at the bus stops. The buses can also capture energy from
the braking. It is planned that the stations can be equipped with solar panels, and is
predicted that the new ones will have a range of charge around 20 miles.
According to Sinautec( one of the companies working with this technology) during
the whole lifetime theses buses saves $200,000 in fuel. It also uses less 40% electricity
than the others electric buses, and, of course, the CapaBus pollute way less.

Figure 3: Capabus recharging at the bus stop
(https://en.wikipedia.org/wiki/Capa_vehicle)

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Figure 4: SINAUTEC Ultracapacitor Bus in Shanghai
(http://www.technologyreview.com/news/415773/next-stop-ultracapacitor-buses/)

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(CHINA)CSR ZHUZHOU ELECTRIC LOCOMOTIVE

Figure 5: Electric Locomotive. Supercapacitor blocks located at the roof
(http://www.railwaygazette.com/news/urban/single-view/view/supercapacitor-light-metro-trainunveiled.html)

The train of the picture above is a locomotive developed by CSR Zhuzhou
Electric Locomotive in association with the Chinese Academy of Engineering. The main
characteristic of this vehicle is that it runs only using electricity stored in supercapacitors
located at the roof of the train.
The train works in the following manner: the blocks of supercapacitor are recharged at a
station while passengers are boarding, and it takes no longer than 30 seconds. After that,
the train is capable of run 2 km at the velocity of 80 km/h and carrying 320 passengers.
CONCLUSIONS

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As seen in this paper, the supercapacitor is a technology which seems to be
very useful and could be more useful yet in the futures, mainly in public transportation
due to its capability of quick recharge combined with the fact that public transport
vehicles have the behave of stop very often to board passengers. Thus, there is a delay
while the passengers are boarding when the supercapacitor in the vehicles are quickly
recharged, what is perfect to implement start-stop systems technology.
REFERENCES

“Volvo Working on Structural Carbon-Fiber Super-Capacitor Technology to Replace
Batteries”
<http://blog.caranddriver.com/volvo-working-on-structural-carbon-fiber-supercapacitor-technology-to-replace-batteries/
”Brake Energy Regeneration System”
<http://www2.mazda.com/en/technology/env/i-eloop/>
”Next Stop: Ultracapacitor Buses”
<http://www.technologyreview.com/news/415773/next-stop-ultracapacitor-buses/>
<https://www.youtube.com/watch?v=LYL6NyU1g3k>
”Supercapacitor light metro train unveiled”
<http://www.railwaygazette.com/news/urban/single-view/view/supercapacitor-lightmetro-train-unveiled.html>
”Hybrid Vehicles”
<https://en.wikipedia.org/wiki/Hybrid_vehicle>
”Supercapacitors”
<https://en.wikipedia.org/wiki/Supercapacitor>

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