Air pollution is one of the world’s leading risk factors for death. And transportation is one of the largest pollution sources. Therefore, electrification becomes a necessary step in reducing air pollution and save lives. As a result, electric vehicles are becoming the future trend in automotive industries. However, there are still some of the concerns which stop consumers from purchasing electric vehicles. Charging faster and longer driving range are two factors that consumers care most. So how to solve these concerns? A high-efficiency charger could be one solution. Level 2 charger takes less time in charging than level 1. But with the lack of charging facilities right now, charging should be available in all situations. This thesis investigates a high-efficiency on-board charger (OBC) that could be used both at residences and at charging stations. The OBC is able to operate at a wide output battery range as well. High efficiency means low losses. Therefore, the proposed topology uses the least number of components to minimize the losses as much as possible. The efficiency is further optimized by using wide bandgap device Gallium Nitride. Since Gallium Nitride shows superior performance in high power applications. The proposed OBC combines a GaN-based bridgeless totem-pole PFC with a synchronous buck converter with innovative active filtering to allow a much smaller dc-link capacitance. The carefully designed passive components occupy less space and help improve power density. Film capacitors are used to replace the conventional electrolytic capacitors since the latter do not have good reliability for automotive applications. The proposed OBC is designed with small current ripple percentage and small output voltage ripple percentage. The simulation results show a high peak efficiency over 98% at both level 1 and level 2 charging mode. The power factor (PF) is over 0.998 and the total harmonic distortion percentage (THD %) is less than 5% at full load condition (3.3 kW). In one sentence, the charger is simple, high efficiency, works with a universal charging system, with a wide output range, and compact. / Thesis / Master of Applied Science (MASc)

The inevitable choice for the automotive industry to suppress greenhouse gas emissions is zero-emission vehicles such as battery electric vehicles. Some of the main barriers regarding the adoption of electric vehicles are range anxiety, and lack of charging infrastructure, which can be addressed by ultra-fast chargers or charging stations. The conventional ultra-fast chargers are low-voltage (LV) connected through line-frequency transformers, which pose disadvantages such as low efficiency, high cost, and large footprints. The medium-voltage (MV) connected charging station is proposed by the researchers to overcome the challenges regarding the conventional chargers by eliminating the line-frequency transformer and direct connection to the medium voltage. The most challenging part of the medium-voltage ultra-fast chargers is the AC/DC stage connection to the medium voltage. Different medium-voltage multilevel converters have been proposed to facilitate the direct connection to the medium-voltage grid. However, disadvantages such as a high number of components and control complexity weaken the strength of medium-voltage connected stations. The main focus of this thesis is on novel advanced medium-voltage multilevel topologies and control techniques for medium-voltage connected ultra-fast EV charging applications. First, a novel controller based on SPWM is proposed to control the flying capacitor voltages of a four-level T-type Nested Neutral Point Clamped (NNPC) topology. Second, a new five-level T-type NNPC topology is proposed that has a minimum number of components in comparison to other existing five-level topologies. To extend the voltage and power rating, a novel seven-level topology is proposed that has the lowest number of components in comparison to other existing topologies. Moreover, three different controllers are developed to control the voltages of the seven-level topology based on Model Predictive Control, where the challenges regarding significant computational burden and weighting factor elimination are addressed. Finally, an MV-connected ultra-fast charging station architecture is proposed, where the proposed seven-level topology is considered as the AC/DC stage. Comparison of the proposed topology to the LV-connected stations shows that the efficiency, cost, and power quality of the charging stations can be improved significantly. / Thesis / Doctor of Philosophy (PhD)

For Sweden, the transition to electric vehicles (EVs) at a faster pace would contribute to fulfilling the sustainability goals of reaching a Net Zero Emission by 2045. The introduction of Evs should, therefore, be a main part of the new strategy for electrification that is being developed by the government. It should also be considered in research and transport planning as the whole transport system is affected. Although, to be successful, a fiscal strategy should be implemented tat make consumers choose to buy/use battery electric vehicles (BEV) rather than internal combusion engine vehicles (ICEV). The results of this study shows that based on public attitudes for climate and transports in Sweden, there is no direct correlation to sales of EV, although there might be indirect correlations. The most plausible explanation for this result is that the fast increase in EV sales is deiven by social status and benefits or pro-environmental symbolism. Another result from the study is that the EV sales increase has a strong correlation to availability of recharging infrastructure. Comparative studies from Norway and other Europeian countreis shows that a mix of fiscal tools, mainly based on tools to make EV more attractive, should be successful. By using the calculations for total cost of ownership (TCO) a suitabile mix of fiscal tools may be created. Even though a positive attitude towards EVs is important, the main driver for EV demand will be a beneficial TCO that makes the EV attractive from a point of view of price and quality. The main fiscal tools recommended are a) A fiscal strategy with a mix of fiscal tools that produces a beneficial TCO for EVs in comparition to ICEVs. These may include subsidies for purchase and insurance cost, financing of the EV, and other benefits that may vary over time, b) Investments in recharing infrastructure, bothe regarding external recharging points and home-recharge stations, to secure a good availability of recharing and c) Structural information to the public and education on the benefits for climate change of an electrification of the transport sector to promote a positive attitude regarding the transition to the new energy economy.

Gegenstand dieser soziolinguistischen Dissertation ist zwar die neupersische Sprache samt ihren drei nationalen Varietäten in Iran, Afghanistan und Tadschikistan, im Mittelpunkt der Untersuchung stehen allerdings die tadschikische und iranische Varietät, anhand der Letzteren es versucht wird, die iranische Sprachauffassung von der v. a. in puncto Schrift und Sprachbezeichnung dem iranischen (und auch afghanischen) Persisch unähnlich erscheinenden Varietät der Tadschiken darzulegen. Dass hier nur das soziolinguistische Verhältnis Irans und Tadschikistans (und nicht Irans und Afghanistans oder Afghanistans und Tadschikistans) zur Frage steht, liegt in der schrift- und aussprachbezogenen Unähnlichkeit der iranischen und tadschikischen Varietäten als auffällige Gegenstücke begründet. Was die Aussprache betrifft, so weisen das afghanische und tadschikische Persisch zueinander mehr Affinität auf als sie es zum iranischen Persisch täten. Und was die Schrift betrifft, so bedienen sich die iranische und afghanische Varietät ein und derselben arabisch-basierten Schrift, während die Tadschiken seit den 1940ern eine kyrillisch-basierte Schrift verwenden. Als theoretischer Rahmen dient das in den 1960ern Jahren in der Soziolinguistik und Dialektologie ansatzweise entstandene und sich seit den 1990ern Jahren fortentwickelnden Konzept der plurizentrischen Sprachen, nach dem das Phänomen der Sprache im Lichte politischer Machtverhältnisse und nationaler Identitätssuche angesehen wird. Nach geopolitischen, ökonomischen und demographischen Kriterien betrachtet, gilt Iran als das dominante Macht- und Sprachzentrum gegenüber den anderen persisch-sprachigen Zentren Afghanistan und Tadschikistan. Daher wird die Forschungsfrage nach der Sprachauffassung der iranischen Kultur-Elite als Ausgangspunkt behandelt. Es wird u. a. den Fragen nach Akzeptanz der Plurizentrizität, Sprachnormativität/-normierung und sprachlicher Konvergenz in/zwischen den nationalen Varietäten nachgegangen. / The subject of this sociolinguistic doctoral thesis is the new Persian language as well as the three national varieties in Iran, Afghanistan and Tajikistan, but the focus of the study is only on two varieties, the Tajik and Iranian Persian. It deals with the linguistic views and perceptions of Iranians or better to say, the cultural elite of Iran, regarding the most distinguished variety of all three varieties of the pluricentric Persian, the Tajik Persian, due to its modified Cyrillic script and writing system. Another reason for focusing on the sociolinguistic relation between Iran and Tajikistan (and not Iran and Afghanistan nor Afghanistan and Tajikistan) is to be found in the dissimilarity between the Iranian and the Tajik varieties, when it comes to the pronunciation. As a result of geographic closeness, the afghan and Tajik Persian have in this sense more resemblances than the Iranian Persian does to one of these two. And regarding the writing system of both Iranian and afghan Persian, it is generally known, that the Arabic-based script and writing system is traditionally in use since centuries, whereas for Tajik Persian first since the 1940s the Cyrillic script is being used as the one and only script. The theoretical framework of the dissertation is the concept of pluricentric languages, which deals specifically with languages as a part of political power relations and national identity discourses. In a geopolitical, economic and demographic context, Iran is considered the dominant power of the three countries, which effects considerably also the question of the common language. For the same reason, it will be the Iranian cultural elite’s perception of language which will be the question of interest, but of course not the only examinable side among the three countries. Furthermore, questions of acceptance of pluricentricity, language normativity/standardization and language convergence in/between national varieties will be investigated.

This thesis was initiated by Penta Investment as a reaction on the significant difference in EV EBITDA multiple of Fortuna and its peers, European listed betting and gaming companies. It seeks to find the reason for more than twice higher multiple and a possibility to increase it by applying best international practices in case there is a feasible way to do it for Fortuna. Three hypotheses address the possible reasons for the difference, peers incomparability, market inefficiency and opportunity for Fortuna to increase the multiple by bringing the most influential KPIs the average level of its peers. The analysis is done with a help of comparative analysis, benchmarking, regression analysis and interviews of equity analysts. As a result, action plan for increasing EV EBITDA multiple for Fortuna is developed.

<p>Research shows that flywheels have a significant potential for improving the performance of EV (Electric Vehicle) drivelines. Flywheels can be used as power buffers that even out the energy flow between the primary energy storage device and the EV traction motor. This improves the potential energy density and extends the lifetime of the primary energy storage device of the EV.</p><p>In this degree project a prototype of a flywheel-buffered driveline was constructed. The flywheel chosen was an electric motor/generator constructed at the Division of Electricity at Uppsala University. Lead acid batteries were used as the primary energy storage device in the driveline and the traction motor was a DC-motor.</p><p>Two DC/DC buck converters were designed for the driveline. The first limited the current from the batteries to the flywheel and the second controlled the power from the flywheel to the traction motor. Both converters were controlled by microcontrollers. The current limiter was controlled by a hysteresis controller and the DC-motor power was regulated manually, under the constraint of a maximum current PI-controller. The buck circuits were simulated in MATLAB Simulink prior to their construction.</p><p>The performance of the driveline was satisfactory, despite the poor efficiency of the DC-motor. The results showed that the efficiency of the flywheel and the power converters was relatively high and that the flywheel had excellent power-buffering properties.</p>

Research shows that flywheels have a significant potential for improving the performance of EV (Electric Vehicle) drivelines. Flywheels can be used as power buffers that even out the energy flow between the primary energy storage device and the EV traction motor. This improves the potential energy density and extends the lifetime of the primary energy storage device of the EV. In this degree project a prototype of a flywheel-buffered driveline was constructed. The flywheel chosen was an electric motor/generator constructed at the Division of Electricity at Uppsala University. Lead acid batteries were used as the primary energy storage device in the driveline and the traction motor was a DC-motor. Two DC/DC buck converters were designed for the driveline. The first limited the current from the batteries to the flywheel and the second controlled the power from the flywheel to the traction motor. Both converters were controlled by microcontrollers. The current limiter was controlled by a hysteresis controller and the DC-motor power was regulated manually, under the constraint of a maximum current PI-controller. The buck circuits were simulated in MATLAB Simulink prior to their construction. The performance of the driveline was satisfactory, despite the poor efficiency of the DC-motor. The results showed that the efficiency of the flywheel and the power converters was relatively high and that the flywheel had excellent power-buffering properties.

Bakgrund: Ett växande intresse för aktiemarknaden har lett till utvecklandet av ett flertalinvesteringsstrategier för att generera överavkastning gentemot marknaden. Att observeraolika multiplar eller bolags marknadsvärde har blivit två populära tillvägagångssätt vidinvesteringsbeslut. Tidigare studier har främst fokuserat på antingen småbolagseffekteneller olika multiplar. Det finns således ett intresse att kombinera två olika strategier ochundersöka småbolagsaktier med låga och höga EV/EBITDA- samt EV/Sales-multiplar. Syfte: Studiens syfte är att analysera huruvida det är möjligt att generera riskjusteradöveravkastning genom investeringar baserade på EV/EBITDA- samt EV/Sales-multiplari bolag som är noterade på OMX Stockholm Small Cap. Vidare ämnar studien analyserainvesteringsstrategiernas historiska prestationer i relation till olikamarknadsförhållanden. Genomförande: Studien har genomförts med en kvantitativ metod och en deduktivansats. Fyra portföljer har konstruerats utefter bolag med låga och höga multiplar som ärnoterade på OMX Stockholm Small Cap under tidsperioden 2007–2020. Både verkligoch ackumulerad avkastning har beräknats för portföljerna för att därefter kunna testatsstatistiskt med parade t-test. Vidare har portföljernas riskjusterade avkastning beräknatsgenom Sharpekvot, Jensens alfa och Treynorkvot. Resultat: Tre av fyra portföljer genererade högre ackumulerad avkastning änjämförelseindex, dock hindrar svag statistisk evidens möjligheten att säkerställaöveravkastningen över tid. Portföljerna med höga EV/EBITDA- och EV/Sales-multiplarpresterade betydligt bättre än portföljerna med låga multiplar. Trots att alla portföljergenererade högre värden än jämförelseindex i Sharpekvot, Jensens alfa och Treynorkvot,kunde inte riskjusterad överavkastning säkerställas för någon portfölj. / Background: A growing interest in the stock market had led to the development ofmultiple investment strategies with the purpose of achieving excess return. Two popularapproaches of investing are choosing companies based on different multiples or based oncompanies’ market capitalization. Previous studies have mainly focused on either thesmall firm effect or different multiples. Therefore, by combining two strategies andinvesting in Small Cap stocks with low and high EV/Sales and EV/EBITDA multiples, anew investment strategy may emerge. Purpose: The purpose of this study is to analyze whether is it possible to achieve riskadjusted excess return by investing in companies that are listed on OMX Stockholm SmallCap based on EV/EBITDA and EV/Sales multiples. Furthermore, the study aims toanalyze the historical performance of the investment strategy during different marketconditions. Method: This study was conducted with a quantitative method and a deductive design.Four portfolios were designed based on companies listed on OMX Stockholm Small Capwith low and high multiples between the years 2007-2020. Both real and cumulativereturn have been calculated for the portfolios in order for them to be statistically testedwith paired t-tests. Furthermore, risk-adjusted return has been calculated for the portfoliosby using the Sharpe Ratio, Jensen’s Alpha and Treynor Ratio. Result: Three out of four portfolios generated higher levels of cumulative return than thechosen stock index. However, because of weak statistical evidence, excess return overtime could not be concluded. The portfolios with high EV/EBITDA and EV/Salesmultiples performed better than the portfolios with low multiples. Despite that all theportfolios generated higher values of Sharpe Ratio, Jensen’s alpha, and Treynor Ratiothan the chosen stock index, the risk-adjusted return could not be statistically proven.

Made available in DSpace on 2016-08-29T14:10:02Z (GMT). No. of bitstreams: 1 tese_2182_.pdf: 279695 bytes, checksum: 822d65b0fc53a3f93c27d1a073dd5d40 (MD5) Previous issue date: 2007-04-16 / Analistas de Comportamento têm apontado relações entre contingências de reforçamento, estados corporais (eventos privados) e eventos públicos. O presente experimento teve por objetivo investigar o controle de contingências programadas sobre eventos privados do tipo sentir, empregando um procedimento que eliciou tais eventos e evocou o tacto dos mesmos (sentimento). Participaram 20 estudantes, de ambos os sexos, com idade entre 11 e 14 anos, que cursavam o ensino fundamental em uma escola privada de Vitória-ES, que executaram as tarefas do software PsychoTacto 2.0. Diante de uma tela dispondo de quatro estímulos (cards), um localizado na parte superior central (estímulo-modelo) e três alinhados na parte inferior central da tela (estímulos-comparação), os participantes respondiam clicando com um mouse em um dos estímulo-comparação a conseqüência era programada de acordo com a contingência básica de reforçamento em operação e, ao término de cada procedimento, relatavam o que sentiram. A freqüência cardíaca e a latência das respostas foram medidas; comportamentos motores e verbais foram registrados por observadores treinados; dos verbais foi inferido controle instrucional sobre o desempenho. Resultados: na fase Reforçamento Positivo predominaram relatos de contentamento (30%), safisfação (20%) e alegria (20%). Na fase Punição Negativa, predominaram relatos de frustração (50%), desapontamento (20%), tristeza (20%), tristeza (20%) e apreensão (10%). Na fase Punição Positiva, predominaram relatos de raiva (30%), aborrecimento (20%), ansiedade (20%), apreensão (20%) e medo (10%). E na fase Reforçamento Negativo, relatos de ansiedade (40%), apreensão (30%) e alívio (30%). Em todas as fases as respostas apresentaram um tempo médio de latência diferente, sendo a maior para o Reforçamento Positivo (3min e 17 seg) e a menor para o Reforçamento Negativo (1 min e 23 seg). As regras formuladas indicaram a não discriminação do desempenho como variável controlada. Os dados motores, verbais e cardíacos combinados mostram que a exposição a contingências pode eliciar eventos privados do tipo sentir e produzir tactos dos mesmos. Não foram registradas discrepâncias entre os dados obtidos entre meninos e meninas. Palavras-chave: Eventos Privados.

As one of the most promising pathways in the transition period towards the low carbon economy, a large scale implementation of electric vehicles (EV) is expected in the near future. Concentration of EV charging in a small area or within a short time will dramatically affect the load demand profile, especially the peak load in the distribution network. As a result, distribution transformers are facing hazards of shortened lifetime due to extra loads, and direct failures caused by potential overloads. Considering the large number of distribution transformers and the massive investment involved, the adaptability of the population of distribution transformers under future EV scenarios should be assessed. In this thesis, an assessment strategy for the future adaptability of distribution transformer population under EV scenarios is introduced. Assessing the adaptability is to understand the impact of the hot-spot temperature, loss-of-life, expected lifetime and failure probability of each individual in the distribution transformer population. Determination of hot-spot temperature of distribution transformers is essential for the assessment. In order to achieve accurate prediction of hot-spot temperatures under EV scenarios, thermal parameters should be refined for individual distribution transformers so that their thermal characteristics can be reflected more accurately than using the generic values recommended for all distribution transformers in the IEC loading guide. Two methods for the refinement are proposed in this thesis. One method is to curve-fit hot-spot temperatures measured in the extended heat run test; and the other is to calculate each parameter with developed equations in the loading guide with standard heat run test results. The assessment strategy is introduced and demonstrated on a group of selected distribution transformers from the population under three EV scenarios, i.e. Business as usual (BAU), High-range and Extreme-range scenarios, which represent 0%, 32% and 58.9% EV penetration levels respectively. Results show that EV charging would be less concerned on the acceleration of thermal ageing than the direct failure due to breakdown caused by decrease of dielectric strength in an event of bubbling. Since the peak load and hot-spot temperature under EV scenarios only last for a short time and would be compensated by low values during the rest time of a day, which eventually leads to a moderate thermal ageing. Occasionally, severe over-ageing can be caused by extremely high hot-spot temperatures, and the lifetime will be reduced to an unacceptable level. However, on such occasions, hot-spot temperatures would be high enough to trigger bubbling and reduce the dielectric strength of transformer's insulation system to a level that is incapable of undertaking the voltage stress, which eventually causes breakdown of transformers. In terms of the failure probability, results show that no distribution transformers are facing failure risks due to bubbling under BAU scenario. Failure starts under High-range scenario. If transformers possessing a failure probability over 50% are identified as high risk, then 13% of investigated transformers are at high risk under High-range scenario, while it increases to 39% under Extreme-range scenario. It is found that the failure probability is dominantly controlled by the peak load, other factors such as transformer age and installation conditions are less influential. A threshold peak load of around 1.5 p.u. is observed that distinguishes transformers in high risk from others under Extreme-range scenario. This observation could be applied to assist the asset management under future EV scenarios that the peak load of distribution transformers should be restricted below 1.5 p.u. to prevent potential failure due to bubbling.