Στην παρούσα διπλωματική εργασία, παρουσιάζεται η ανάπτυξη συναρτήσεων και ρουτινών, οι οποίες χρησιμοποιούνται για την ψηφιακή απεικόνιση διάφορων οργάνων μέτρησης του πίνακα ενός ηλεκτρικού οχήματος, πάνω σε οθόνη TFT LCD ολοκληρωμένου συστήματος. / This diploma thesis represents the development of functions and routines wich are used to digitalize an electrical vehicle's panel using an LCD TFT screen of an embedded system (LPC2478STK).

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2007. / The work presented in this thesis forms part of the participation of the University of Stellenbosch in an electric vehicle project. The thesis deals with three aspects of the dynamics and energy management of the electric vehicle. The three aspects that are dealt with are the suspension system of an electric vehicle with in-wheel propulsion, the traction control of an electric vehicle and the energy system of such a vehicle. An investigation is presented in the thesis on the effect the mass of the hub motors has on the safety, stability and comfort of the electric vehicle. The investigation is done through a system frequency analysis and a comparative simulation. A comparison is made between a standard vehicle and a vehicle with in-wheel propulsion. A vehicle model is derived for the simulation of the vehicle. Finally, a few of the results of physical measurements performed are also presented. The traction control requirements of an EV are investigated. A discussion is given on the parts that make up an EV’s traction control system. A few examples of possible traction control systems are given through a step by step evolution of a traction control system. A vehicle model is derived for both static and kinetic friction conditions. The model is used in simulations to illustrate the need for traction control in EV’s. The thesis presents two methods for choosing a battery pack size, in terms of energy capacity etc. The difficulties associated with choosing a battery pack, using each of these methods are given. A battery pack choice for the specific electric vehicle, is presented. The measurements of one of the required charge-discharge cycles are presented to illustrate the charge and discharge curves of the battery cells used. The management of energy flow within the energy system of the EV is crucial, especially if regenerative braking is utilized. This is to protect the battery cells as well as to extend the range of the vehicle. The thesis presents the evaluation of an energy management system (EMS) using ultra capacitors as auxiliary storage device. An electronic load system is designed to simulate the operation of the vehicle motors. The transfer functions for the EMS and load system are derived and used to design the respective control algorithms. The control algorithms were implemented in both simulation as well as a laboratory setup to show the operation of the EMS. A new energy system configuration is presented. The aim of the new configuration is to solve certain problems encountered when implementing a conventional EMS. The operation of the new configuration is discussed. A comparative study is made between the conventional and the new configurations.

published_or_final_version / Environmental Management / Master / Master of Science in Environmental Management

<p>This thesis presents the study and the design analysis of apermanent magnet synchronous motor (PMSM) for the tractionapplication of an electric vehicle. An existing inductiontraction motor for an electric forklift benchmarks the expectedperformances of the proposed PMSM design. Further, thepossibility of using the identical stator as the one used inthe induction motor is explored for the fast prototyping. Theprototype motor is expected to be field-weakened and to have aconstant power speed range (CPSR) of 2.5 to 3.</p><p>A design approach based on the CPSR contour plot in aninterior permanent magnet (IPM) parameter plane is derived toobtain the possible designs that meet all the designspecifications and the targeted CPSR. This study provides thepossible alternative designs for the subsequent futureprototype motors.</p><p>An analytical approach to estimate the iron loss in PMsynchronous machines is developed and included in the designprocedure. The proposed technique is based on predicting theflux density waveforms in the various regions of the machine.The model can be applied at any specified load condition,including the field-weakening operation region. This model canbe ultimately embedded in the design process for a routine usein loss estimations.</p><p>The first prototype motor with an inset permanent magnetrotor has been built and the available measurements are used tovalidate the design performance. In particular, the thermalanalyses based both on the lumped-circuit approach and thenumerical method are compared with the measured results. Asecond and possibly a third prototype motor targeting a widerand higher performance will be carried out in the continuingphase of the project.</p><p><b>Keywords:</b>Constant Power Speed Range, Electric Vehicles,Field-weakening, Reference Flux Linkage, Iron Loss, PermanentMagnet Synchronous Motor, Thermal Analysis</p>

The purpose of this study is to examine possible tariff designs for a Swedish DSO to better reflect the individual’s future use of the grid when it comes to the expected effects of EV. A qualitative research method with a combination of an experimental and comparative case study design was carried through. The literature review involved data gathering within the subjects of grid tariff design, pricing of natural monopolies and behaviour related to electricity use. Empirical data consisted of quantitative data from the grid in combination with interviews of 5 respondents. With a systematic combining approach, the theoretical framework, empirical data and analysis evolved simultaneously. The results were analysed through emerging themes and evaluated with simulations. The study has shown that a static and easy to understand tariff is preferable. A reflective way to price distribution of electricity does not imply a correct breakdown of allocating costs to direct causes of them. When designing the tariff, a DSO must be aware of the psychological barriers and consequences a tariff design can induce. By that we find the combination of a fixed, demand and ToU component should give incitements well enough to make customers mindful of how they use their electricity. During a transition to a new tariff design, a customer focus approach should be used, were transparency and simplicity are keywords. The future could imply a shift from static to dynamic tariffs designs in which enabling technologies will have to ease the complexity for the customer in order to break down the psychological barriers.

No description available.

Lithium-ion batteries are today finding use in automobiles aiming at reducing fuel consumption and emissions within transportation. The requirements on batteries used in vehicles are high regarding performance and lifetime, and a better understanding of the interior processes that dictate energy and power capabilities is a key to strategic development. This thesis concerns aging in lithium-ion cells using electrochemical tools to characterize electrode and electrolyte properties that affect performance and performance loss in the cells.   A central difficulty regarding battery aging is to manage the coupled effects of temperature and cycling conditions on the various degradation processes that determine the lifetime of a cell. In this thesis, post-mortem analyses on harvested electrode samples from small pouch cells and larger cylindrical cells aged under different conditions form the basis of aging evaluation. The characterization is focused on electrochemical impedance spectroscopy (EIS) measurements and physics-based EIS modeling supported by several material characterization techniques to investigate degradation in terms of properties that directly affect performance. The results suggest that increased temperature alter electrode degradation and limitations relate in several cases to electrolyte transport. Variations in electrode properties sampled from different locations in the cylindrical cells show that temperature and current distributions from cycling cause uneven material utilization and aging, in several dimensions. The correlation between cell performance and localized utilization/degradation is an important aspect in meeting the challenges of battery aging in vehicle applications.   The use of in-situ nuclear magnetic resonance (NMR) imaging to directly capture the development of concentration gradients in a battery electrolyte during operation is successfully demonstrated. The salt diffusion coefficient and transport number for a sample electrolyte are obtained from Li+ concentration profiles using a physics-based mass-transport model. The method allows visualization of performance limitations and can be a useful tool in the study of electrochemical systems. / <p>QC 20140512</p>

<div>In recent years, there has been considerable growth in the adoption and technology development of electric vehicles (EV), autonomous vehicles (AV), and ride sharing (RS). These technologies have the potential to improve transportation sustainability. Many studies have evaluated the environmental impacts of these technologies but the existing literature has three major gaps: (1) the adoption of these three technologies need to be evaluated considering their impact on each other, (2) many existing models do not evaluate systems on a common ground, and (3) the heterogeneous preferences of riders towards these emerging technologies are not fully incorporated. To address these gaps, this work studies and quantifies the environmental and efficiency gains that can be gained through these emerging transportation technologies by developing a Parameterized Preference-based Shared Autonomous Electric Vehicle (PP-SAEV) agent-based model. The model is then applied to a case study of New York City (NYC) taxis to evaluate the system performance with increasing AV, EV, and RS adoption.</div><div><br></div><div>The outputs from the PP-SAEV model show that replacing taxi cabs in NYC with AVs along with RS potentially can reduce CO\textsubscript{2} emissions by 866 metric Tones per day and increase average vehicle occupancy from 1.2 to 3 persons in vehicles with passenger seating capacity of 4. A prediction model based on the PP-SAEV output recommends that 6000 vehicles are needed to maintain the current level of service with 100\% AV and RS adoption using capacity 4 taxis. Taxi fleets with capacity 4 with high RS and low AV adoption are also found to have the least CO\textsubscript{2} emissions. Because the heterogeneous sharing preferences of riders have shown as the major limiting factor to ride sharing, these heterogeneous sharing preferences are further modelled. The results show that high service levels are achieved when all the riders are open to sharing, and the maximum service level is reached when 30\% of riders will only accept shared rides and 70\% of the riders are either indifferent to sharing or prefer to use ride sharing over riding alone. Additionally, the service level and waiting time of riders that are inflexible (will accept only shared or non-shared rides) are greatly impacted by varying mix of riders with different sharing preference. Finally, an optimization model was built to site charging stations in a system with continually increasing EV adoption. Using the best charging station locations, transforming a fleet of autonomous or traditional vehicles to electric vehicles does not significantly change the system service level. The results show that increasing the EV adoption in fleets with 100\% RS and AV adoption reduced the daily CO\textsubscript{2} emissions by about 861 Tones and transforming a fleet of traditional taxi cabs to electric taxi cabs reduced the daily CO\textsubscript{2} emissions by 1100 Tones.</div><div><br></div><div>In summary, this dissertation evaluates the potential growth of autonomous vehicles, ride sharing, and electric vehicles in systems where riders may have heterogeneous sharing preferences, from a system performance`s perspective and assesses the environmental impacts. The developed model and the insights gained from this study can inform policy makers to develop sustainable transportation systems incorporating the emerging transportation technologies.</div>

Abstract: As China is facing environmental problems, they are producing positive policies in order to stimulate the sales of electric vehicles. In addition, China is one of the largest electric vehicle markets in the world and the electric vehicles market has a promising growth potential. In light of this, this thesis aims to investigate the factors affecting Chinese consumers’ willingness to purchase electric vehicles. This thesis draws on rational choice theory to analyze the six determining factors including driving range of electric vehicles, charging infrastructure, purchase cost, government financial incentives, individual environmental awareness and perceived social influence, as electric vehicles are not cheap goods and make consumers take full consideration before buying. This study adopts a quantitative approach and conducts a survey to investigate this topic. Based on 249 online questionnaires from Chinese consumers, this study employs SPSS to conduct a regression analysis to test the six determining factors. The empirical results indicate that charging infrastructure, government financial incentives, individual environmental awareness and perceived social influence have significant impact on Chinese consumers’ willingness to purchase electric vehicles, while our results do not show that the driving range of electric vehicles and purchase cost matters in influencing Chinese consumers’ willingness to purchase electric vehicles. Meanwhile, this study contributes to the research on the consumption of electric vehicles by providing an empirical context of China, considering rational choice theory and understanding perceived social influence. Also, this study provides relevant suggestions to electric vehicle manufacturers and the Chinese government about how to encourage the Chinese to adopt electric vehicles in China. Keywords: Electric Vehicles, Willingness to purchase, SPSS, Rational choice theory, China

Background:          The growing number of electric vehicles gives rise to a whole new reverse supply chain. Once the electric vehicle batteries reach their end-of-life, societal and governmental pressure forces automotive manufacturers to set up a network for disposing the hazardous batteries. Although, the volumes of returned batteries remain low, volumes will increase in upcoming years. Current networks and processes related to the return flow of electric vehicle batteries are not well established, nor well defined. Thus, creating an urgency to develop efficient collection networks.   Purpose:                  The purpose of this study is to investigate how reverse logistics networks are currently set up and to provide an overview of how the different actors and processes are connected. In addition, this thesis aims to identify challenges encountered by logistics providers and recyclers. By doing so, we hope to contribute to the research gap of which factors that constitutes a bottleneck for further development of the reverse logistics chain of electric vehicle batteries.   Method:                  The thesis conducts an interview study and is qualitative in nature. Semi-structured interviews generated empirical data, which was analysed through cross-case analysis incorporating a thematic analysis. Through this analysis we were able to achieve new theoretical understandings in connection to institutional theory.   Conclusion:             Through empirical findings a detailed framework of the reverse logistics chain of EVBs is portrayed. Furthermore, different challenges span over the processes illustrated in the framework. This presents an overview which is not found in current literature and extends current research on this topic.