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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

The rise of electric two-wheelers in China : factors for their success and implications for the future /

Weinert, Jonathan X. January 1900 (has links)
Thesis (Ph. D)--University of California, Davis, 2007. / Text document in PDF format. Title from PDF title page (viewed on August 28, 2009). "Received by ITS-Davis: December 2007"--Publication detail webpage. Includes bibliographical references (p. 132-140).
2

Design and development of rapid battery exchange systems for electric vehicles to be used as efficient student transportation a thesis /

BeVier, Jonathan Austin. Vanasupa, Linda. January 1900 (has links)
Thesis (M.S.)--California Polytechnic State University, 2009. / Title from PDF title page; viewed on August 21, 2009. "July 2009." "In partial fulfillment of the requirements for the degree [of] Master of Science in Engineering." "Presented to the faculty of California Polytechnic State University, San Luis Obispo." Major professor: Linda Vanasupa, Ph.D. Includes bibliographical references (p. 100-101).
3

Design of a three phase four quadrant variable speed drive for permanent magnet brushless DC motors

Dakora, Jonas-Yelee January 2016 (has links)
Submitted in fulfillment of the requirements for the Master of Engineering Degree, Department of Electronic Engineering, Durban University of Technology, Durban, South Africa, 2016. / The aim of this research project is to design a three phase four quadrant variable speed drive (VSD) for a permanent magnet brushless direct current motor (PMBLDC) that can be applied to an electric bicycle (e-bike). The design is confined to PMBLDC motors with a maximum power rating of 1.5kW. The speed controller operates in current mode at a maximum voltage and current rating of 50V and 30A, respectively. The VSD has the ability to smoothly control the current delivered to the DC motor and therefore controls its torque. The motor’s current is limited in all four quadrants of operation, and its speed is limited in the forward and reverse directions. The performance of the proposed DC motor VSD system is tested on an electric- bicycle. The PMBLDC motor has three hall sensors embedded into the stator to determine rotor position. A phase switcher module interprets the position signals and produces a switching pattern. This effectively transforms the BLDC motor into a direct current (DC) brushed motor. The unipolar switching scheme used ensures that current flows out of the battery only for motoring operation and into the battery during regenerative braking. The current and torque are directly proportional in a BLDC motor. Torque control is achieved in the BLDC motor using a single channel current controller. The phase switcher current is monitored and used to control the duty cycle of the synchronous converter switches. The proposed e-bike speed control system provides efficient control in all four quadrants of operation and it is a suitable alternative for a low cost transportation mode. / M
4

Charging of lithium-ion batteries with a hydrogen fuel cell for an electrical bicycle.

Monjaux, Aurelien. January 2012 (has links)
M. Tech. Electrical Engineering. / Hydrogen is in the middle of many discussions as being a good alternative to petrol for the struggle against pollution and global warming. The fact that hydrogen can be found in infinite quantities such as in water or in space makes it a renewable energy. It is the object of much research works in order to be used in replacement of fossil energy such as in hybrid vehicles. However, the main shed of hydrogen is the difficulties to store it. Indeed, being the first element of the periodic table, it is the lightest, spreads a lot and can burn easily. The aim of this project is to achieve the wiring diagram of an electrical bicycle. The use of a hydrogen fuel cell allows feeding the electrical motor of the vehicle. However, due to a matter of low response time of the fuel cell, lithium-ion batteries are also used. Indeed, at the start state for instance, the fuel cell needs some time to warm and reach the nominal temperature of functioning. Lithium-ion batteries allow feeding the electrical motor during the warm up time but also to respond to peak of load. Hybrid motorization represents the future of car industry and tends to be used as a replacement of petrol engine partly responsible of greenhouse gases emissions. Some of those vehicles are already put in place in some big cities all over the world and allow moving rapidly without polluting. This project concerns a hybrid system for an electrical bicycle but the idea is to extend to bigger kind of vehicles.
5

Innovative approaches to recycling of small and electric motors from end-of-life vehicles, electric bicycles and industrial machinery

Link, Rainer January 2016 (has links)
Recycling and recovery of materials and energy from waste is a key factor to mitigate virgin material demands and reduce resource consumption by utilising waste as a resource for new products. However, some critical materials, such as neodymium, are barely recycled because of missing information on amount and disposition of these critical materials within the waste streams. The goal of the study is to quantify recycling potentials from small and electric motors originating from end-of-life vehicles (ELV), electric bicycles and industrial machinery in Germany and the EU with focus on currently lost rare earth elements. Furthermore, innovative approaches to improve recycling of these motors shall be investigated. Therefore, a calculation model to predict current and future waste streams and the incorporated recycling potentials has been developed. The results show an increasing trend of recycling potentials from small and electric motors for all waste streams. The recycling potential of neodymium is estimated at a range of 150 t to 240 t in 2020 in Germany. However, data inaccuracy and the calculation model are likely to cause overestimation of actually available recycling potential and have to be interpreted carefully. In conclusion, disassembly of small and electric motors from ELV and electric bicycles in combination with a subsequent specific recycling process has been identified as promising to improve utilisation of the recycling potentials of rare earth elements from small and electric motors. However, in case recycling quotas are the prior goal of improvement, the application and further optimisation of post shredder technology is more relevant.
6

ELCYKELN SOM HÅLLBART TRANSPORTSÄTT : En studie om hur väl rustade Sveriges kommuner är för elcykeln

Christiansen, Filip January 2023 (has links)
The world is facing a change that needs to reduce the carbon output that humanity and its technologies produce. One such shift is the swap to non-fossil fueled cars and more sustainable ways to travel. Travelling by bicycle has for several decades been one of the most sustainable ways to travel and now the evolution of bicycling is upon us with the boom of electric bicycles.    With the electric bicycle, you can push the active distance you can commute with a bicycle as you get a helping hand when traversing steep hills and a speed boost as well. Not to mention that you won't arrive drenched in sweat. As the evolution of sustainable traveling methods continue, how does the cities and urban areas around them evolve? As we see more charging posts for electrified cars and local buses, not much has been done within the spaces for electric bicycles. So, what is the future for the electric bicycle as a sustainable transport method and how should the municipalities and cities plan for it?    By using content analysis on different kinds of plans that municipalities work with when planning for transport methods, the goal is to see how widespread planning for electric bicycles is and if there are any other factors affecting this. By using a pre-set list of keywords and a PDF reader, the goals were to search each plan for the keywords. A hypothesis is that if a municipality mentions the electric bicycle, then the municipality may plan for it. Two categories were made, one that mentions the electric bicycle for what it is and nothing more. The other if the municipality in some greater context describes planning for the electric bicycle.   The result show that 24% of Swedish municipalities have plans that includes planning regarding the electric bicycle. Three factors were created that may explain why and if a municipality had planning or not for the electric bicycle and these were geographical aspects, the acceptance date of the plan and local factors.   For the electric bicycle to have a place in the future as a sustainable transport method it needs to be recognized as one. As well as given the space within our municipalities and city's, to be able to be used safely and not pose a risk to other users. As the electric bicycle has other requirements on the infrastructure than regular bikes, they need more space, wider roads etc. That is why it is crucial to plan for them, if they are to be among the future sustainable transport methods.
7

Importación y venta de kits para conversión de bicicletas convencionales a eléctricas y bicicletas eléctricas como una alternativa de transporte ecológico en Lima Metropolitana

Giraldo Espinoza, César Bruno, Watanabe Rivera , Yoshi, Cotrina Honorio De Soto, Juli Yelixa 30 June 2020 (has links)
La presente investigación se titula “Importación y venta de kits para conversión de bicicletas convencionales a eléctricas y bicicletas eléctricas como una alternativa de transporte ecológico en Lima Metropolitana”. Dicha idea de negocio surgió como una iniciativa de los ejecutores del proyecto para hacer frente a la necesidad de buscar un medio de transporte para mitigar el problema de la congestión vehicular en Lima Metropolitana. Uno de los problemas que aqueja a la ciudad de Lima es la congestión vehicular, esto produce estrés por el mayor tiempo invertido para trasladarse de un lugar a otro; ante ello, el presente estudio brinda una alternativa ante este problema social. Durante el año 2020, la demanda sobre el uso de las bicicletas eléctricas se ha convertido en muy buena alternativa para movilizarse, asimismo sería una respuesta eficaz a raíz de la pandemia que se está viviendo a nivel mundial. La finalidad de disminuir la posibilidad del contagio del Covid-19, reducir la congestión, el consumo de combustible, la contaminación y los tiempos de desplazamientos. / The present research is entitled “Import and sale of kits for conversion from conventional bicycles to electric bicycles and electric bicycles as an alternative for ecological transport in Metropolitan Lima”. This business idea emerged as an initiative of the project's executors to address the need to seek a means of transport that to mitigate the traffic congestion that exists in Metropolitan Lima. One of the problems that binds the city of Lima is the vehicle congestion, this causes stress for the longer time spent to move from one place to another; before this, the present study provides an alternative to this social problem. During 2020, demand for the use of electric bicycles has become a very good alternative for mobilization, and it would also be an effective response to the pandemic that is being experienced worldwide. The aim is to reduce the possibility of covid-19 transmission, reduce congestion, fuel consumption, pollution and travel times. / Trabajo de investigación
8

Motives, perceptions and experiences of electric bicycle owners and implications for health, wellbeing and mobility

Jones, Tim, Harms, Lucas, Heinen, Eva 11 November 2020 (has links)
The sale of electrically assisted bicycles (‘e-bikes’) is growing at a rapid rate across Europe. Whereas market data is available describing sales trends, there is limited understanding of the experience of early adopters of e-bike technology. This paper investigates the motives for e-bike purchase, rider experience and perceived impact on mobility, health and wellbeing through in-depth interviews with e-bike owners in the Netherlands and the UK. Findings revealed that the motive for purchasing e-bikes was often to allow maintenance of cycling against a backdrop of changing individual or household circumstances. E-bikes also provided new opportunities for people who would not otherwise consider conventional cycling. Perceptions of travel behaviour change revealed that e-biking was replacing conventional cycling but was also replacing journeys that would have been made by car. There was also a perception that e-biking has increased, or at least allowed participants to maintain, some form of physical activity and had benefitted personal wellbeing. Technological, social and environmental barriers to e-biking were identified. These included weight of bicycle, battery life, purchase price, social stigma and limitations of cycle infrastructure provision. Additional research is necessary to quantify actual levels of mode substitution and new journey generation among new e-bike owners and the impact of e-biking on promoting physical health and mental wellbeing.
9

E-bike users are lazy… and healthy : A study in consumer behaviour on the symbolic values of e-bikes, why some want e-bikes and others avoid them.

Ahlbom, Joel, Andersson, Daniel January 2019 (has links)
Research question: To examine what aspects affect some consumers to avoid e-bikes and others to desire them. Purpose: The main purpose of this study is to see if e-bikes have a symbolic value. We aim to see if e-bikes is associated as an environmentally friendly product. We will examine stereotypes and brand avoidance. Further we will see what attributes consumers associate with typical users of e-bikes. Theory: To test our research question we chose our main theory of the matching process between self-image and typical user. Prior studies on e-bikes in areas as typical users and environment were analyzed. Previous studies on e-bikes were analyzed in areas such as environment and typical users. Methodology: A survey was made on two groups who are underrepresented in sales of ebikes. Students aged 21-30 and cycling enthusiasts. Results and conclusions: • We found that e-bikes have symbolic value. • Many respondents perceive e-bike users as environmentally friendly, comfortable and lazy. • E-bikes being perceived as environmentally friendly can be a pre-purchase indicator for students, but not for cycling enthusiasts • Different groups of students have conflicting user imagery, one group describe e-bikers as lazy, and another group describe e-bike users as healthy • The stereotype that e-bike users are old is not very frequent • Viewing e-bike users as lazy influences impacts the perceived value and are likely to lead to brand avoidance

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