Technical Report, Draft #2
S.U.N
Team - Civil Engineering Programme
Singapore
Institute of Technology
10
Dover Drive
Singapore
138683
13th
March 2018
Chew
Men Leong
Land
Transport Authority
1
Hampshire Road
Singapore
219428
Dear
Mr. Chew,
Re:
Proposal for Improvement of Electric Bus System in Singapore
Enclosed
for your kind consideration is the following proposal for the improvement of
the electric bus system in Singapore.
This
proposal has been prepared in response to your letter of authorization calling
for proposals. The proposal has been developed in light of the problem that the
LTA is facing with electric vehicle while spearheading Singapore’s electric
vehicle uptake in public transportation. Our team’s intention is to offer a
systematic method that could more aptly address the problems associated with
the present electric bus system and infrastructure.
The
report consists of a review of the identified problems, the rationale behind
our proposed solution, and a detailed summary of all related primary and
secondary research. As potential electric bus users ourselves, we have provided
information on the flaws of the current electric bus system, piloted by
Go-Ahead Singapore, a case study of the potential solution and a detailed
discussion on how the relevant agencies may improve on them.
We
would like to express our gratitude to you for taking the time to read through
the proposal. Your consideration of our suggestions for transforming the public
electric bus system more efficient and emission-free is greatly appreciated.
Yours
sincerely,
Teo
Shu Min
(S.U.N
Team Representative)
Executive Summary
This report outlines the problems with current electric bus system in Singapore and the advantages of wireless charging technology for electric buses, whilst proposing to LTA to conduct a pilot study for this technology in resolving these problems. Electric buses have zero emissions, run quieter than conventional buses, contribute less to the carbon footprint, require less maintenance, and are much cheaper in the long run, as compared to diesel buses. However, the battery efficiency and range of the K9 electric buses tested by Go-Ahead Singapore are lowered due to the warm and humid climate in Singapore with additional battery capacity used for cooling. With the implementation of a wirelessly charged bus system, electric buses can be charged while in motion, hence improving the accessibility of charging and reducing charging time.
This report outlines the problems with current electric bus system in Singapore and the advantages of wireless charging technology for electric buses, whilst proposing to LTA to conduct a pilot study for this technology in resolving these problems. Electric buses have zero emissions, run quieter than conventional buses, contribute less to the carbon footprint, require less maintenance, and are much cheaper in the long run, as compared to diesel buses. However, the battery efficiency and range of the K9 electric buses tested by Go-Ahead Singapore are lowered due to the warm and humid climate in Singapore with additional battery capacity used for cooling. With the implementation of a wirelessly charged bus system, electric buses can be charged while in motion, hence improving the accessibility of charging and reducing charging time.
See Neng Wei
Umar Abdul Aziz Bin Ahmad Shamsuddin
Teo Shu Min
Shu Min
graduated from Singapore Polytechnic with a diploma in civil engineering with
business in 2017. Her passion lies in the structural design of buildings and
their structural plans. She has been involved in drafting construction drawings
for a project located in Qurayyat, Oman, for an independent water project
during her internship. At present, she is an undergraduate student in civil
engineering at Singapore Institute of Technology.
Table of Content
2 Problem statement
3 Purpose Statement
4 Proposed Solution
4.1 Case Study (SNW)
4.2 Benefits of Solution
4.3 Limitations of Proposed Solution
4.4 Application of OLEV in Singapore
5 Methodology
5.1 Primary Research
5.2 Secondary Research
6 Conclusion
Reference
Appendix A
Appendix B
1
Introduction
Singapore is ranked first in
Asia, and second globally as the most sustainable city. However, Singapore
accounts for 0.12% of global greenhouse gas emissions. Singapore aims to
achieve 36% reduction goal in carbon emissions intensity by 2030 (Feng, 2015).
Singapore’s transportation
sector contributes 15.32% to the total greenhouse gas emissions in 2016 (Feng,
2015). While the usage of electric vehicle (EV) is one way to reduce greenhouse
emissions, the country is facing challenges to fully embrace the usage of EVs
as the main means of commute. Challenges such as the high cost of EVs,
Singapore’s limited EV infrastructure and the considerable safety aspects of
plug-in EVs generally deter local consumers and Singapore’s public transport
operators to consider the switch to EV. According to Kuttan
(2017), EV drivers are afraid of travelling long distances with the risk of
their vehicle batteries running flat. He added that the accessibility of fast
chargers is the only factor that will encourage people to be more open to
conventional EV.
Today, Singapore’s buses
dominantly run on natural gas and diesel. With greater awareness on
environmental sustainability, the LTA will be buying 50 new hybrid buses and 60
new pure-electric buses (CNA, 2017). The K9 pure-electric buses which will be
tested by Go-Ahead Singapore needs five to 10 hours charging time to travel 250
km. These buses emit no greenhouse gas emission or noise, thus reducing air and
noise pollution. Their traveling distance, however, will be reduced due to the
warm and humid climate in Singapore with additional battery power used for
cooling (Lim, 2016).
E-buses
have zero emissions, run quieter than conventional buses, contribute less to
the carbon footprint, require less maintenance, and are much cheaper in the
long run, as compared to diesel buses. However, long travel distances, high
turnover rate of buses in Singapore, limited charging periods, and heavy
battery requirements make electric buses unsustainable in Singapore. To
eliminate these problems, the usage of wireless charging technology in e-buses
can be implemented.
2
Problem statement
An ideal pure-electric bus
system in Singapore should be energy efficient, self-sustainable, and has good
accessibility to charging points. However, the K9 electric buses which is
tested by Go-Ahead Singapore needs five to 10 hours charging time to travel 250
km, is reduced because of the warm and humid climate in Singapore with
additional battery power used for cooling (Lim, 2016). With the implementation
of a wireless charging bus system, this will improve the accessibility of
charging while reducing charging time.
3 Purpose Statement
The purpose of this report is to outline to LTA the advantages of
the wireless charging technology for electric buses which tackles the
challenges in the current system, and propose to them to conduct a pilot study
to test the wireless charging system.
4 Proposed Solution
The solution to this problem is
to use wirelessly charged electric buses. ‘Wireless charging technology’ or
power transfer through magnetic induction has been tested since the early 2000s
on electric buses in several countries like Italy, China, USA, Japan and Korea.
Inductive charging requires a charging station
which has an induction coil in it. This then produces the electromagnetic
field which transfers the energy across the gap to corresponding induction coil
in the device. The device then converts the energy from the magnetic
field back into a useable electrical current which is then used to charge the
battery (Thomson, 2014). These buses receive power without physical
contact unlike the conventional usage of electric cables for plug-in EVs. This
simplifies the charging process as buses need not be charged only in depot or
interchange but instead, charged on the go.
4.1 Case Study
An example for this technology was tested by Korea Advanced Institute of Science of Technology (KAIST). This technology granted electric buses to be charged while in motion. It eliminates the need for remote static charging stations and introduces charging infrastructure embedded in the roads. As a result of charging on-the go, the company’s e-buses utilised smaller, inexpensive batteries which in turn reduced the vehicle weight. With a lighter load, the buses expanded less energy. Moreover, wireless charging plates could be built beneath the roads without having any impact on the cityscape.
An example for this technology was tested by Korea Advanced Institute of Science of Technology (KAIST). This technology granted electric buses to be charged while in motion. It eliminates the need for remote static charging stations and introduces charging infrastructure embedded in the roads. As a result of charging on-the go, the company’s e-buses utilised smaller, inexpensive batteries which in turn reduced the vehicle weight. With a lighter load, the buses expanded less energy. Moreover, wireless charging plates could be built beneath the roads without having any impact on the cityscape.
KAIST is the first in the world
to introduce Shaped Magnetic Field in Resonance (SMFIR) technology that safely
deliver energy to an electric vehicle wirelessly while vehicle is in motion. It
was developed as part of the KAIST online electric vehicle (OLEV) project. By
having energy transferred, the OLEV transport system is wirelessly powered by
underground coils without any mechanical contact. A pickup device
installed under the vehicle works to gather the magnetic field efficiently from
power grids embedded in the road and convert it into electric energy for
vehicle operation. The pickup coils are tuned to a 20kHz resonant frequency and
are modelled to have maximized exposure to the generated magnetic field, as a
result, the efficiency of the magnetic power transmission can be maximized
while decreasing the magnetic field leakage. I. S. Suh. (n.d.)
According to the article “KAIST
OLEV Transport System,” Using the SMFIR technology, a power transmission
efficiency of 83% at a ground height of 20cm and a 75kW of power capacity can
be achieved. This translates to the most efficient wireless power transfer
system available for commercial deployment to e-buses. With the provision of
power supply infrastructure embedded on Five to 15 percent of the whole bus
route, it is sufficient to wirelessly powered OLEV bus for its operation. The
power strips that supply OLEV buses with electric power will be installed at
bus stations, bus stops and traffic junctions which allows the battery of the
OLEV bus to be recharged. With the SMFIR technology, OLEV bus has its battery
capacity reduced to 20% compared to an normal electric bus. OLEV complies with
the international electromagnetic fields (EMF) standards of 62.5mG which is
within the safety margin for human health. Segment technology is introduced to
control the power supply by switching on when it detects OLEV buses, hence, it
distinguish OLEV buses from other vehicles. As a result, it will prevent EMF
exposure and standby power consumption to other road consumers.
4.2 Benefits
of Solution
1.
The implementation of the OLEV system helps to simplify the
charging process without the need of anyone handling heavy charger cables and
plugs. (KAIST, n.d.)
2.
The system can virtually run 24/7 with the
increased accessibility to wireless charging segments that ensures the buses to
be charged without stopping. It also prevent chances of battery from running
flat. (Brian, 2013)
3.
The OLEV system can be extended to cars,
lorries and other vehicles. The usage of wireless charging vehicles will reduce
the amount of carbon emission making Singapore’s land transportation more
eco-friendly. (Fischer, 2016)
4.
With technology advancement, the cost of
batteries will become cheaper than conventional EV batteries. This will promote
EV uptake in the and this will provide cheaper replacement cost. (KAIST, n.d.)
5.
OLEV weight of batteries will be lighter,
allowing e-buses to use less power to move the bus and batteries will be more
efficient which reduces the frequency to charge. (KAIST, n.d.)
6. The need to
build expensive recharge facilities can also be eliminated. This will reduce
the space efficiency which can be put to other use. (Suh. I. S., n.d.)
7. This
system significantly allows batteries to be smaller and reduces the amount of
lithium used. (Whitlock, 2016)
8.
OLEV
technology ensures safety with their OLEVs and supplies it with electric power
through pickup devices build under the vehicle’s body. (KAIST, n.d.)
9.
The success of the system entails a promising
return for Singapore to pioneer the advancement of electric vehicle systems in
the tropics.
10.
OLEV technology can be incorporated into
autonomous vehicles to achieve Singapore’s 2030 Smart Nation goal.
11.
A virtual fossil fuel-free urban transportation
can be achieved with the increase in electric vehicle uptake and improved
charging system and infrastructure.
4.3 Limitations
of Proposed Solution
1.
Limited info from LTA on e-bus systems or trials conducted in
Singapore. Information that could be disclosed have already been published
online. LTA representative could not disclose more information.
2.
The exact proposed locations of charging plates on Sg roads have
to be further considered and studied. Proposed locations could be the bus
depots, bus stops and traffic junctions. These locations are ideal for charging
e-buses, however traffic junctions necessitate the usage of the GLIDE system
which detects the presence of vehicles and pedestrians at the junctions of
major roads. Little is known about the effect of magnetic coupling on the GLIDE
system’s wire sensors.
3.
The unpredictability of traffic conditions may cause buses to run
out of power before reaching the nearest charging strip.
4.
Given that Singapore would be the first tropical country to test
wirelessly charged buses using the OLEV technology, little is known about its
performance as Korea where this system had been tested is non-tropical climate.
5.
It is challenging to pick a suitable bus route to work well with
the bus as it determines the distance of the bus stops and to obtain maximum
efficiency.
6.
It will be hard to ensure drivers do not sway while driving on the
road as the induction coil will be placed at the center of the road.
7.
With the current technology, battery prices are still expensive
and bulky which might bring conflict to the project.
8.
This idea can be implemented only if the government take this idea
into consideration.
4.4 Application
of OLEV in Singapore
While the idea of revamping the
public bus system in Singapore into wireless may seem challenging, a pilot
study can be first be conducted to assess the feasibility of the OLEV
technology on Singapore’s public buses. As part of the engineering design and development
process, a bus route can be selected within the Punggol Digital District to
apply the power supply infrastructure. The route will operate a couple of OLEV
buses over a 6km one-way trip, which will take approximately 20 minutes for
each trip. The objective is to design the most efficient and optimized power
supply infrastructure. This includes identifying how long the powered track
should be, where it should be installed, and what combination of the segments
should be laid. As a rule of thumb, the powered track should be installed where
the driving power exceeds the battery discharge capacity, so that the buses can
have a enough power to be driven.
5 Methodology
5.1 Primary
Research
Primary research in the form of interview was done with SIT-UoG
Deputy Programme Director for Civil Engineering and SIT Programme Director for
Telematics (Intelligent Transportation Systems Engineering). The objective is
to listen to a professional context on electric buses in Singapore, this
wireless charging system for electric buses and its feasibility. The Interview
transcript with SIT-UoG Deputy Programme Director for Civil Engineering will be
shown in Appendix A.1.
5.2 Secondary
Research
Online sources are used for the
information of the different technologies available, tested in other countries.
After evaluating the different technologies, the OLEV technology by KAIST has
been widely quoted in this report due to its extensive design information and
its feasibility as a solution to the problem mentioned.
6 Conclusion
To conclude, the implementation of wirelessly charged e-buses for
Singapore's public bus system could be one way to solve the problems associated
with electric buses. It will, however, take time for the pilot study to be
completed and evaluated before LTA decides to implement the system fully into
Singapore’s roads, and observe large-scale benefits to the economy, environment
and local consumers.
Reference
Fischer, M. (2016). Scandinavia’s first
electric bus with wireless fast charging. Retrieved from :
https://news.vattenfall.com/en/article/scandinavia-s-first-electric-bus-wireless-fast-charging
One Motoring. (n.d.). Green Link Determining
(GLIDE) System. Retrieved from:
https://www.onemotoring.com.sg/content/onemotoring/en/on_the_roads/traffic_management/intelligent_transport_systems/glide.print.html
Lim, A. (2016). E-bus to ply public
route in trail lasting six months. The Straits Times. Retrieved from :
http://www.straitstimes.com/singapore/e-bus-to-ply-public-route-in-trial-lasting-six-months
National Environment Agency. (2016). Singapore
second biennial update report 2016. Retrieved from
http://www.nea.gov.sg/docs/default-source/energy-waste/climate-change/second-biennial-update-report-(16-dec-2016).pdf
Thomson, K. (2014). Problems with
Wireless Charging. Retrieved from:
https://cambrionix.com/blog/problems-with-wireless-charging/
N.P. Suh, D.h. Cho , & C.T. Rim. (n.d.). Design
of On-Line Electric Vehicle (OLEV). Retrieved from
www.springer.com/cda/content/document/cda_downloaddocument/9783642159725-c1.pdf?SG
KAIST. (n.d.). KAIST OLEV Transport System.
Retrieved from: http://www.smfir.co.kr/20120323/sub02/KAIST_OLEV_en.pdf
Whitlock, R. (2016). Wireless energy
transfer strips for electric vehicles and buses. Retrieved from:
https://interestingengineering.com/wireless-energy-transfer-strips-for-electric-vehicles-and-buses
Kim, D.-J. (2015). Kmatrix. Retrieved
from:
https://kmatrix.kaist.ac.kr/wireless-charging-electric-bus/
Brian, M. (2013). Electric avenue:
Korean buses now wirelessly charge as they drive. Retrieved from: https://www.theverge.com/2013/8/7/4596898/korea-wireless-charging-buses-kaist-olev
Suh. I. S. (n.d.). Application of Shaped Magnetic
Field in Resonance (SMFIR) technology to future urban transportation.
Retrieved from
http://www.buspress.eu/wp-content/uploads/2013/08/CIRP-Design-2011-Paper34-Suh.pdf
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