Technical Report

Introduction

In the past, the idea of a solar powered vehicle has been the subject of much discussion. Hence, in February 1992, a group of ambitious and eager students decided to proceed in the realization of a vehicle that would have the sun as its main energy source.

The protection of the environment is a primary concern nowadays, thus University students are especially inclined to create solar-powered vehicles of higher technology in order to curb the disastrous and growing effects of urban pollution. Our team decided to create a solar powered vehicle in order to attempt to find newer and ecologically-safer transportation methods and to support technological exchanges between various Universities as well as to encouragere search on renewable energies in Quebec. It stands to reason that we will not change the world of transportation; however, if we elevate the level of environmental consciousness, our efforts will not have been in vain.

This report shall serve as an introduction to the different aspects of our project, including a general idea of the competitions, a technical description of the electrical and mechanical systems, the relative costs of the vehicle and the travelling expenses of the team, the schedules for the stages of development, and lastly, the advantages of sponsoring our organisation.

L'École de technologie supérieure

ETS was founded in 1974 and offers engineering courses at the University level. The various programs are suited to increase the economical and technological development and growth in Quebec. The University's Bachelor programs are all recognized by the Quebec Order of Engineers and the Canadian Bureau of Accreditation.

ETS is unique in the sense that it is the only University-level institution in Quebec which offers cooperative studies to technology and computer science CEGEP graduates. ETS is strongly concerned in assuring these CEGEP students a continuing education in their field of study. The University keeps close and strong connections with the industrial environment, especially on the research and the development levels. This guarantees a pertinent training program based on the present industrial needs. Its pedagogical strength relies heavily on the practical application and on experience.

Students at ETS are invariably practical and resourceful as well as very aware of the industrial world's present situation. Through the special formation received at ETS, these students are accustomed to creating and inventing projects, thus explaining their well-above average standards in inter-university competitions, on provincial, national and international levels.

The solar car team

A project of such a large scope as a solar vehicle requires the assistance and the involvement of many specialized individuals. The project consists in as much mechanical as electrical technology, thus it is important to have a dynamic and diversified team. Our team is made up of twenty electrical and mechanical engineering students, professional research staff as well as professors, all fascinated by solar energy.

On the electrical level, we are proud to include in our team two professional researchers who are part of the Power Electronics and Industrial Control Research Group (P.E.I.C.R.G.) of ETS, a technician specializing in electrical motors and ten or so electrical engineering students. We are also honoured to include Dr. Kamal Al-Haddad, an electrical engineering teacher who has a Ph.D. in Power Electronics as well as vast experience in the renewable energy field.

The mechanical aspect of the project is assumed by ten or so mechanical and automated production engineering students. The members of the mechanical section generally have an excellent knowledge of aerodynamics and of the materials which will be used in the vehicle's components, such as aluminium, steel, magnesium, etc. The body of the vehicle will be entirely designed by the mechanical section of the team and will be constructed at GSM PRODUCTION INC, Quebec. This company has an enviable reputation in the composite materials field all over Canada.

Thanks to the researchers and the professors of ETS, the Eclipse project is bound to succeed and to have a promising future in international-level competitions.

The solar vehicle and the environment

Today's energy-resource needs are many and present themselves in various and diverse forms. To satisfy the increasing demands of energy in an industrial society, it is a must to develop new forms of easily available energy, able to satisfy the growing demands as well as being recyclable. The sun's thermic energy is the latest form of renewable energy to have surfaced in the market. This energy is in no way threatened by inflation and is far from extinction. It would be wise to direct our efforts towards such energy as numerous interesting and fascinating ideas present themselves.

At the present time photovoltaic cells are costly due to the fact of the techniques used inproducing them. However, the advantages to the society and the environment of a vehicle propelled by these cells are many and need to be discovered. The alarming amount of carbon(CO) presently in the atmosphere requires immediate and serious attention, especially from vehicle producers as automobiles are largely responsible. Although the vehicle may prove to be less performing than traditional petrol-driven automobiles, it will however, be ecologically safer and more friendly to the environment. Therefore, efforts must be undertaken in order to render solar panels more efficient and less costly, thus increasing its usage.

In analysing solar energy, it is evident that the necessary energy to produce a solar vehicle is much inferior to a petrol-driven vehicle and much less harmful to the environment. Moreover, a solar vehicle would lessen the amount of carbon in the atmosphere, while also being quieter than today's vehicles. Considering the above-mentioned facts, solar energy contributes to making our environment more ecologically sound. In many countries, social measures have been enforced in order to curb the ever-increasing petrol consumption problem. Various cities with serious environmental problems are proposing and establishing laws which would force the inhabitants to use electric automobiles or other less harmful methods of transportation. Firms are therefore directing their research towards different vehicle manufacturing processes in order to be able to respond to the demand in the future.

Competitions

Solar vehicle competitions are organized in many countries around the world including Australia, Canada, Great Britain, Switzerland and the United States. In North America, competitions usually cover distances ranging from 500 to 2000 km. Short distances races favor powerful vehicles while less powerful but more efficient vehicules are advantaged in long distance races.

During 1995, our team will terminate the solar vehicle and participate in several promotional events (exhibitions, demonstrations, etc.) In 1995, we will participate in two competitions, including the renowned "Sunrayce" competition and the Canadian Solar Challenge.

In the beginning of May 1995, we plan to partake in the "Canadian Solar Challenge". This closed circuit competition runs over a period of one day thus covering a distance of approximately 500 km. Fifteen or so vehicles usually participate in this competition.

As mentioned above, in 1995 we plan to participate in the most renown American Competition, the "Sunrayce". The starting point of this 1850 km race is in Indianapolis, Indiana and the finish line will be in Golden Springs, Colorado. The number of Universities allowed to join is limited to 40. This competition will take place at the beginning of June and will last for a total of 10 days. It goes without saying that the seriousness of the project as well as the quality of the file will be the determining factor in choosing the participating Universities.

Our team will have to face many renown competitors. Included among the potential competitors are:

• Queen's University, Canada
• California State University, USA
• Massachusetts Institute of Technology, USA
• Stanford University, USA
• University of Maryland, USA
• University of Michigan, USA
• Western Washington University, USA
• Western Michigan University, USA

Although incomplete, this list mentions the best competitors of today. Eventhough some of the competitors did not compete last year in North America, they nonetheless represent potential competitors in the years to come.

It is evident that the champion teams are usually funded by major sponsors. To name a few:

• Epson
• Ford
• General Motors (GM)
• Honda
• Delco
• Siemens
• IBM
• Intel
• Swatch
• etc...

Description of the electrical system

The electrical section of the team includes University undergraduate students and professionals in Power Electronics and Industrial Controls Research. The design of the electrical system allows the students, the professors and the researchers to increase their personal knowledge while supporting the progress of technology in the field of solar energy at ETS.

Our team used the most up-to-date technological developments in the field of power electronics and was as innovative as possible. Resonance converter technology allows convertors to reach an elevated degree of efficiency as well as high output power.

Solar Panels
The monocrystalline based solar panels will measure 8 squared meters with conversion-ratio efficiency of 14% which will supply approximately 1.1 kW of energy on sunnydays. The panels shall conform to the vehicle's shape in order to increase its aerodynamism.
Capacitive filtered series parallel resonance convertor
This convertor is needed to adapt the charge of the solar panels in order for these to supply a maximum amount of power, no matter the amount of sun. The output current of the convertor will be constantly sampled by a micro-controller and the gain of the convertor shall be continually adjusted in order to obtain the maximum power possible. This step is called "powertracking". Moreover, taking the measurements of the current and the voltage of the batteries is necessary in order to keep them charged within their limits. Other convertors will also be necessary to increase the voltage of the batteries from 100 to 300 volts to feed the motor.
Switching power supply
The function of this convertor is to lower the battery voltage to 12V in order to supply the secondary systems of the vehicle. This convertor will be entirely independent and will need no numerical controlling.
The controls
The controls will be microprocessor-based, which will control the first resonance convertor, the motor, the energy consomption as well as the instrument panel.
The batteries
The batteries will be lead-acid and will have a maximum power of 5kWh. For short distance competitions and when we will be allowed to recharge the batteries by external sources. However, a maximal power of 2.5 kWh will be imposed during endurance competitions when batteries can be recharged by solar energy alone. This procedure will allow us to obtain better results as the sun's probable energy-giving fluctuations do not justify or support the use of the maximal capacity of 5kWh which would diminish the vehicle's performance by excess weight.
The Motor
The vehicle's motor will be propelled by a direct current electronic commutative motor of 2.7 HP supplied by Baldor USA. This motor, on the leading edge of technology, will offer a level of performance superior to 90%.
The secondary system
The secondary circuit contains all the digital instrumentation and the lights of the vehicle. The secondary system is a must at the registration of the vehicle in order to conform to the rules of certain competitions.

Description of the mechanical system

The involvement of the mechanical section of the team is essential in a project of such calibre. The design and the creation of such a vehicle depends on rigorous construction criteria. The solar vehicle has been conceived in order to respect the following criteria: aerodynamism, surface uniformity, stability, accessibility and security. In the following text , we will try to show how the criteria are met.

Energy consumption is a factor directly associated with the aerodynamism. This factor is a deciding factor in the performance of this type of vehicle. In order to obtain maximal efficiency, we established strict conditions for ourselves :

1. The drag coefficient of the air-path friction is reduced to its minimum
2. The vehicle body consists of a single unit
3. The oblong and symmetrical shape favour a more fluid air flow.

In order to diminish the coefficient of our penetration, it is important to attain a surface with a weak slope. As it is very difficult to obtain such a surface without sacrifying the vehicle's capacity, we have designed the vehicle by respecting the following conditions :

1. A compact shape
2. Maximisation of the surface in order for it to be as even as possible
3. Maximisation of the interior space for the equipment.

Concerning the general appearance of the vehicle, we have considered the following points :

1. A layout with the lowest possible centre of gravity
2. The shape is based on the profile of an aeroplane's wing
3. The vehicle is based on a uni-body design for maximum rigidity.

A lightweight vehicle that travels on roads must respect stability criteria. This is very important as in some competitions, the vehicle's stability is tested as it faces strong head-on and lateral winds. The two points which we judged important are :

1. The position, the location, the dimension and the number of wheels
2. The location of the batteries.

Owing to the vehicle's dimensions, all the parts of the vehicle must be easily accessible for maintenance and repair purposes. After studying the different options carefully, we chose the following solutions :

1. Removable steering wheel to facilitate the driver's access
2. Superior part of vehicle detachable in two (2) sections.

The security aspect of the vehicle must not be ignored. As the competitors are subjected to certain hazards, our team designed the vehicle respecting certain security precautions in order to minimize the risks. The following measures are those we have adopted :

1. Peripheral vision for the driver
2. Location of the third brake light in the superior part of the vehicle
3. Shock resistance
4. Quick evacuation methods for the driver in case of emergency.

For the construction of our vehicle, our team chose materials with qualities specific to our needs. We attempted to acquire materials on the cutting edge of technology in order to elevate the efficiency of the vehicle, while securing a certain expertise in the field of alloys and composites. We based our selection on materials with good physical qualities such as :

1. Mechanical resistance
2. Lightness
3. Ease of replacement
4. Ability to easily re-supply.

The drivers windshield was designed in order to offer the following qualities:

1. A smooth surface
2. Tinted in order to diminish the luminous intensity.

Solar vehicle cost breakdown

In order to complete a competitive level vehicle at minimum cost, readily available industrial quality components have been studied and the following price list shows the approximate cost for all components :

The total cost estimate of 67050 $ represents the cost for the vehicle alone. This estimate does not take into account such costs as transport or board for the vehicle or operating team during competitions. As we are planning to participate in several exhibitions, other costs such as transportation, board, etc. are to be added. On the following page, the estimated costs of competitions and exhibitions are listed. Costs referring to the competition division include the "SUNRAYCE" which we plan to partake in, in 1995, as mentioned in the "Competition" section of this report. The exhibition costs include the estimated costs to participate in different expositions as well as the costs of additional travelling to participate in media and publicity events.

Sponsorship

Industry involvement is vital in order to realize our project. The creation of a solar vehicle involves many human resources, much time and money. To be able to realize such an impressive project, we must have industry support. As industry will directly contribute to the advancement of our project, we, in return, offer several advantages. Being associated with a project such as ours, includes numerous advantages :

• Your name is associated with a dynamic and ambitious team.
• Your name is associated with a clean and non-polluting technology.
• You will directly be helping technology progress at the solar energy level.
• Because the public is very interested in solar energy as well as in the competitions, these activities therefore profit from good coverage from the media such as radio, newspapers, magazines, television, etc. Moreover, ETS has always enjoyed good relations with the various media.
• The competitions take place around the world; your company will therefore receive world-wide publicity.
• The modern design and the aerodynamism of the vehicle portray a higher technology futuristic image for your company.
• You allow future engineers to acquire very good experience on project administration and management levels, as well as gaining experience working in a team atmosphere.
• Your name will be associated with those of major companies who sponsor teams from the world-over and benefit from an excellent reputation.

In addition to these advantages, the solar vehicle team is committed to offering the following services :

• A monthly report indicating our progress as well as our competition rankings
• Your company's logo in the foreground at exhibitions
• Your company's logo on all official solar vehicle sweaters
• A copy of the video of the construction of the vehicle once it is completed
• Your company's logo on official posters relating to the solar vehicle
• Your company's logo on both the solar vehicle as well as the escorting vehicle
• References made at exhibitions, competitions, newsletters, etc., that your company is a major sponsor of the solar vehicle
• Possible loan of the vehicle for research or publicity purposes.

The organization can already count on important sponsors such as :

Conclusion

The solar vehicle team wishes to express its thanks to you for having perused our project report. With your support, we plan to complete the project by the end of April 1995. Such a project can become an important event at the University level in Canada, especially if it is financed and supported by industry during the creation of the vehicle. Certain companies have already shown their interest towards this project and, moreover, we can count on ETS's complete support and assistance. Although the total amount needed to complete the project may seem somewhat costly, it is important to remember that such a project will benefit the University with leading edge technology and enviable expertise in the solar energy field for years to come. The team in charge of designing the solar vehicle is open to suggestions as well as to the participation of companies in order to remain as efficient and as competitive as possible.

Annex

For all correspondence with the solar vehicle team :