The aim of this master thesis is to develop a suggested methodology for how to use Mavenoid infrastructure to improve customer support of DEFA EV chargers. Mavenoid is a company that helps other companies automate customer support, especially troubleshooting. This is done with Mavenoid models, interactive selfhelp tools that guide end users without technical knowledge through the troubleshooting process. Mavenoid models provide value both by deflecting cases (the end user solves the problem on their own using the model) and triaging cases (collect relevant information about the problem before escalating the case to a human support agent) The main methodology to develop a suggested methodology was learning by doing, using the suggested methodology to actually implement Mavenoid models available to end users on DEFA’s home page. This was complemented with a literature review, interviews and data analysis from model usage. The suggested methodology is to iteratively follow the steps of deciding which models to build, make priorities within these models, build the models, analyze their performance and continuously improve the models. To decide models, carefully evaluate DEFA’s support situation to decide where Mavenoid models would have the greatest impact. Force yourself to make quantitative assumptions to estimate a payback time for each possible model. For each model, carefully prioritize what to include and where the focus should be using estimates of frequency, value and time to model. Build the models to maximize deflection and triage and minimize abandoned sessions. Collect and analyze data from model usage and use this information to improve the models. To prioritize between possible improvements, force yourself to make quantitative assumptions of value and time to model and rank improvements by payback time. Limit the improvements you make either by time available or desired payback time. The potential business opportunity between Mavenoid and its customers is more attractive the more support cases the customer has and the larger fraction of end users that use Mavenoid. The business opportunity varies greatly with assumptions that are very difficult to estimate accurately at the early stages of a Mavenoid implementation. This indicates that Mavenoid models should be implemented step by step and assumptions updated when more data is available. Implementing Mavenoid models can be both positive and negative from a sustainable development perspective. They could encourage people to repair products instead of replacing them, scale renewable energy technology faster and remove boring and repetitive tasks from support staff. On the other hand, they might not be appreciated by all end users, could lead to increased electricity consumption and potential unemployment for support staff. Being about a largely unresearched topic, the results in this thesis are relatively subjective. This suggested methodology was used and proved to work to implement Mavenoid models for DEFA EV charging stations but it should be seen as one possible methodology, not the confirmed best methodology. / Syftet med detta examensarbete är att utveckla en metodologi för hur Mavenoids teknologi kan användas till att förbättra kundsupporten för DEFAs elbilsladdare. Mavenoid är ett företag som hjälper andra företag att automatisera kundsupport, särskilt felsökning. Detta görs med Mavenoidmodeller, interaktiva självhjälpsverktyg som guidar slutanvändare utan teknisk kunskap genom felsökningsprocessen. Mavenoidmodeller ger värde både genom att slutanvändaren löser problemet på egen hand genom att använda modellen (deflection) och genom att samla relevant information om problemet innan ärendet eskaleras till teknisk support (triage). Den huvudsakliga metoden för att utveckla metodologin var att lära genom att göra, faktiskt implementera Mavenoidmodeller och göra de tillgängliga för slutanvändare på DEFA: s hemsida. Detta kompletterades med en litteraturöversikt, intervjuer och dataanalys av hur modellerna användes. Den föreslagna metodologin är att iterativt följa stegen besluta vilka modeller som ska byggas, prioritera inom dessa modeller, bygga modellerna, analysera data från dem och kontinuerligt förbättra modellerna. För att bestämma modeller, utvärdera DEFAs supportsituation noggrant för att bestämma var Mavenoid-modellerna skulle ha störst inverkan. Tvinga dig själv att göra kvantitativa antaganden för att uppskatta en återbetalningstid för varje möjlig modell. För varje modell ska du noggrant prioritera vad du ska inkludera och var fokus ska vara genom att använda uppskattningar av frekvens, värde och tid att modellera. Bygg modellerna för att maximera deflection och triage och minimera övergivna sessioner. Samla och analysera data från modellerna och använd denna information för att förbättra modellerna. För att prioritera mellan möjliga förbättringar, tvinga dig själv att göra kvantitativa antaganden om värde och tid att modellera och rangordna förbättringar efter återbetalningstid. Begränsa de förbättringar du gör antingen utifrån tillgänglig tid eller önskad återbetalningstid. Den potentiella affärsmöjligheten mellan Mavenoid och dess kunder är mer attraktiv ju fler supportärenden kunden har och ju större andel slutanvändare som använder Mavenoid. Affärsmöjligheten varierar kraftigt med antaganden som är mycket svåra att uppskatta i början av ett projekt att implementera Mavenoidmodeller. Detta indikerar att Mavenoidmodeller bör implementeras steg för steg och antaganden uppdateras när mer data finns tillgängligt. Implementering av Mavenoid-modeller kan vara både positivt och negativt sett till hållbar utveckling. De kan uppmuntra människor att reparera produkter istället för att byta ut dem, skala upp förnybar energiteknologi snabbare och ta bort tråkiga och repetitiva uppgifter från teknisk support. Å andra sidan kanske de inte uppskattas av alla slutanvändare, kan leda till ökad elförbrukning och potentiell arbetslöshet för de som jobbar inom teknisk support. Eftersom examensarbetet handlar om ett relativt outforskat ämne är resultaten relativt subjektiva. Denna föreslagna metodologi användes och visade sig fungera för att implementera Mavenoidmodeller för DEFAs elbilsladdare men den bör ses som en möjlig metodologi, inte den bekräftat bästa metodologin.

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Electric vehicle (EV) adoption continues to rise, yet EV sales still represent a small portion of vehicle sales in most countries. An expansion of the DC fast charging (DCFC) network is likely to accelerate this revolution towards sustainable transportation, giving drivers more flexible options for charging on longer trips. However, DCFC presents a large load on the grid which can lead to costly grid reinforcements and high monthly operating costs – adding energy storage to the DCFC station can help mitigate these challenges. This thesis first performs a comprehensive review of DCFC stations with energy storage, including motivation, architectures, power electronic converters, and detailed simulation analysis for various charging scenarios. The review is closely tied to current state-of-the-art technologies and covers both academic research contributions and real energy storage projects in operation around the world. It is identified that the battery energy storage systems (BESSs) with active front end converter provides high efficiency with reasonable power density in a DCFC station. It is also realized that the isolated DC/DC converter interfacing BESS and EV determines the overall efficiency of a DCFC station with a low grid connection. Secondly, this thesis analyzes the impact of active front end based DCFC stations connected to a grid distorted with background voltage harmonics. In active front end based DCFC stations, background voltage harmonics produce current not only at the frequencies of the distorted voltage, but also at other coupled frequencies. Various mitigation techniques, such as increasing inner control loop gain, grid voltage feedforward, and selective harmonic compensation, have been adopted in industry to reduce the emissions originating from distorted background voltage. However, although these techniques are effective in suppressing the current at the harmonic orders present in the background voltage, they deteriorate the emission at coupled frequencies. This thesis provides the theoretical explanation of this phenomenon, which is verified by simulation of a two-level active front end in PSCAD/EMTDC. This thesis also discusses the proper treatment of current emission due to background voltage harmonics. Thirdly, the thesis identifies the semi dual active bridge (semi-DAB) converter as an ideal candidate as the interfacing isolated DC/DC converter between the BESS and the BEV. A novel control strategy is proposed for the semi-DAB converter to achieve wide voltage gain while increasing the efficiency at operational points with high input voltage and low output voltage, which is a commonly occurring scenario when the BESS is fully charged, and the EV battery is at low charge. Furthermore, this thesis also provides an algorithm to determine the required phase-shift in real time for any operating point, eliminating the need to devise the control trajectory offline. A 550 V, 10 kW experimental prototype is built and tested to validate the proposed control strategy. With a 25 A constant charging current, the prototype shows the proposed control strategy can improve efficiency by up to 3.5% compared to the well-known dual phase shift control at operating points with high input voltage (450 – 550 V) and low output voltage (150 – 275 V), with a peak efficiency of 97.6%. Finally, this thesis proposes a novel variable turns-ratio semi-DAB converter to improve its overall efficiency even further when the input voltage is high and the output voltage is low. Furthermore, a control law is also proposed to determine the turns-ratio, i.e., the operational structure of the converter, which reduces the converter peak and rms current. The 550 V, 10 kW prototype is modified to accommodate the variable turns-ratio high frequency transformer to test the proposed converter and control. The proposed converter with control can further improve the efficiency at many operating points compared to single turns-ratio semi-DAB with DPS control. The peak efficiency achieved is 98.5%. / Thesis / Doctor of Philosophy (PhD)

Bakgrund: I den lågräntemiljö som varit under senaste året har allt fler sökt sig till aktiemarknaden för att få avkastning på sina pengar. En teoretisk vattendelare är huruvida det är möjligt att överavkasta marknaden. Detta är ett område som studerats under en längre period där resultat mellan studier skiljer sig. Denna studie undersöker med utgångspunkt i multipelstrategi möjligheten att överavkasta marknadsindex på de nordiska aktiemarknaderna.  Syfte: Studien syftar till att undersöka möjligheten till att generera en överavkastning mot marknadsindex genom en multipelstrategi utifrån multiplarna P/E, P/B, EV/EBITDA samt EV/S på de nordiska aktiemarknaderna. Vidare kommer studien även att jämföra, analysera och diskutera skillnader mellan de olika aktiemarknaderna.  Metod: Studien har använt sig av en kvantitativforsknings ansats med ett deduktivt tillvägagångssätt. Under perioden 2011–2021 skapades 64 portföljer i på den svenska, norska, finska och danska marknaden med 16 i varje land, där de 20 högsta samt lägsta P/E, P/B, EV/S och EV/EBITDA delades in i portföljer och sedan viktades om var tredje och tolfte månad.  Resultat: Studiens resultat visar på att det var möjligt att överavkasta marknadsindex på de olika aktiemarknaderna, det finns dock ingen multipel som påvisar någon signifikans på samtliga marknader. Den portfölj som lyckades prestera bra över flera marknader var låga EV/EBITDA, men den uppvisar enbart signifikans på tre av fyra. Den portfölj som presterade bäst i varje land skiljer sig däremot från varandra. / Background: In the low-interest rate environment that has been in recent years, more and more people have sought out the stock market to gain a return on their money. A theoretical opinion separator is whether it is possible to outperform the market. This is an area that has been studied overa longer period, where results between studies differ. Based on a multiple strategy, this study investigates the possibility of outperforming market indices in the Nordic stock markets. Purpose: The purpose with this study is to see if there is a possibility to generate an excess return towards the market index through a multiple based strategy with P/E, P/B, EV/EBITDA and EV/S onthe Nordic stock markets. Furthermore, the study will compare, analyze and discuss the difference between the Nordic stock markets. Method: The study applies a quantitative method with a deductive approach. During the period 2011-2021 64 portfolios was created for Sweden, Norway, Finland and Denmark with 16 in each countrywith the 20 highest and lowest P/E, P/B, EV/S and EV/EBITDA and had a holding period of either three or twelve months. Results: The study result shows that it is possible to gain an excess return compared to the index in the different comparing markets, though there is not a single multiple that shows a statistic significance in every market. The portfolio that outperformed the index in all markets was EV/EBITDA, but only showed a significance in three out of four. The portfolio that outperformed the market most was different in each country.

The global shift towards Electric Vehicles (EVs) is driven by their energy efficiency, lower emissions, and reduced dependence on fossil fuels. As the demand for EVs continues to rise, the need for EV ultra-fast chargers becomes paramount to enable faster charging times and facilitate long-distance travel without compromising convenience. In this context, solid-state transformers (SSTs) have emerged as a promising technology to replace traditional line-frequency transformers (LFTs) in various applications, including EV charging stations. SSTs offer improved system controllability, power factor correction capabilities, and reduced size and weight through the utilization of medium-frequency transformers (MFTs). This thesis focuses on enhancing the efficiency and power density of the MFT used in SSTs. A 1.2 MVA SST for EV ultra-fast charging stations is designed and simulated. The SST incorporates average controllers responsible for regulating the output voltage and the input power factor, as well as, voltage and power balancing controllers to ensure stable operation among its cells. Furthermore, a design methodology for optimizing the MFT used in DC-to-DC converters for SST-based ultra-fast chargers is introduced. The methodology is optimizing the efficiency and power density of the transformer based on the transformer parameters input by the designer. A software tool is developed to streamline the design process and enable the optimization of various parameters, such as core material, size, and winding configurations. The tool facilitates the development of high-performance MFTs for SST applications. The developed MFT optimization methodology is utilized to design a 100 kW, 20 kHz MFT, resulting in a remarkable 22.7% improvement in power density compared to conventional design methods. The transformer showed superior efficiency and power density compared to MFT designs in literature. Additionally, two scaled-down transformers are designed and tested at 5 kW, employing both conventional and optimization methods. The results demonstrate a significant 57.8% improvement in specific power. / Thesis / Master of Applied Science (MASc)

Electric Vehicles represent a small niche market today, but is predicted to grow rapidly over the next years. In order to prepare for this upcoming trend it is the networks of Electric Vehicle Charging Stations (EVCS) must expand, leading to an increasing demand for EVCSs. The EVCS market is thus becoming increasingly more popular to companies, and therefore this study’s purpose is to investigate this market and its competitive situation. The method used in this study includes a brief market analysis and a competitor analysis. The market analysis includes identification of the EVCS markets together assessing the future of the markets, and identification of EVCS market drivers and restraints. The competitor analysis includes competitor identification, classification and analysis. The top ten competitors are analyzed by the use of document content analysis, the analysis involves understanding the competitors’ target customers, how they do business and how their marketing material is structured. The three most promising EVCS markets, both currently and in the future, are the Asia Pacific, Europe and the North America markets. Most of the top competitors are active within these three markets. Regional developments, and market drivers and restraints of these markets have been identified. The opportunities in the EVCS markets are many as they are relatively unexploited markets without any actual market leaders, and also that all markets are predicted to grow at a very high rate over the coming decade in parallel with the projected mass adoption if Electric Vehicles (EVs). / Idag utgör elfordon endast en liten nischmarknad i transportmarknaden, men denna förväntas växa snabbt under de närmaste åren. För att kunna hantera marknadsetableringen av elfordon måste elfordonsladdningsinfrastrukturen byggas ut, vilket leder till en ökad efterfrågan på elfordonsladdningsstationer. Elfordonsladdningsmarknaden förespås således bli allt mer intressant för företag. Detta examensarbete genomförs på grund av detta växande intresse, då studiens syfte är att undersöka elfordonsladdstationsmarknaden och dess konkurrenssituation. Metoden som används i denna studie inbegriper en kort marknadsanalys och en konkurrensanalys. Marknadsanalysen innehåller identifiering av elfordonsladdningsmarknaderna, vad som driver och hindrar marknaderna, och en bedömning av hur framtiden ser ut för marknaderna. I konkurrensanalysen ingår identifiering, klassificering och analys av de olika konkurrenterna. De tio mest konkurrenskraftiga konkurrenterna analyseras med hjälp av dokumentinnehållsanalys, syftet med analysen är att förstå konkurrenternas målgrupper, hur de gör affärer och hur deras marknadsföringsmaterial är strukturerad. De tre mest lovande elfordonsladdningsmarknaderna, både nu och i framtiden, är marknaderna i Asien och Stillahavsområdet, Europa och Nordamerika. De flesta av de analyserade konkurrenterna är verksamma inom dessa tre marknader. Den regionala utvecklingen, och vad som driver och begränsar marknaderna har identifierats för de tre mest lovande marknaderna. Eftersom dessa marknader är relativt oexploaterade i samband med att de förväntas växa med väldigt hög takt det kommande decenniet parallellt med massanvändningen av elfordon är möjligheterna många för de företag som inriktar sig mot elbilsladdning.

Bakgrund: Effektiva marknadshypotesen innebär att det inte går att utnyttja systematiska avvikelser på marknaden. Trots det finns det etablerade investeringsstrategier som investerare använder sig av för att generera överavkastning. Syfte: Syftet med studien är att undersöka huruvida det går att generar överavkastning genom att investera i företag som uppvisar en låg eller hög EV/EBITDA-multipel. Variablerna bransch och risk kommer även att undersökas med utgångspunkt från den eventuella förekomsten av en investeringsstrategi som genererar överavkastning. Genomförande: Teori inom området har byggt upp en grundförståelse för problemet, empiri har sedan hämtats från de olika företagen för att få fram EV/EBITDA-multiplar till de ingående portföljerna i studien. Aktiekurser har även inhämtats för att bygga grunden till empirin. Resultatet har sedan jämförts med OMXSPI samt med den riskjusterade avkastningen. Resultat: Av resultatet framkommer att det går att utnyttja en investeringsstrategi där investering görs i låga EV/EBITDA-multiplar. Effekten är tydlig på hela Stockholmsbörsen, samt i två av de undersökta branscherna, sällanköpsvaror och tillverkningsindustrin. Det spelar ingen roll vilken riskpreferens investeraren har då portföljer med låga multiplar genererar högst avkastning och även innehåller lägst betavärde. / Background: The efficient market hypothesis alleges that an investor cannot systematically earn excess return. However there are established investment strategies that are being used in the stock market to obtain this excess return Aim: The aim of the thesis is to examine if it is possible to earn excess returns by investing in companies that indicate a low or high EV/EBITDA multiple. The variables industry and risk will also be examined with the possible presence of an investment strategy where excess return can be obtained as a base. Completion: Theory within the field has built an understanding of the problem, empirics have then been gathered to obtain EV/EBITDA multiples and stock prices to perform the study. Portfolios of high and low multiples have been composed to analyze the result. The result has been compared to the development of the OMXSPI index and to the risk adjusted return for the portfolios. Result: The result shows that an investment strategy where investments are made in a low EV/EBITDA-multiple can be used to earn excess return on the Swedish stock market. The effect is most present at the Stockholm stock exchange and in the manufacturing industry and industry for durable goods. The investors risk aversion does not affect the decision, thus low multiples generate the highest return with the lowest beta value.

L'objectif de cette thèse est l’étude de la charge rapide de batteries lithium-ion basée sur la méthode de la compensation chute ohmique. Cette méthode permet théoriquement de réduire le temps total de charge des batteries. Dans cette thèse, cette méthode a été mise en œuvre sur trois types différents de cellules de format 18650 : C/ FP, C/NMC et LTO/LFP. Cette méthode montre de bons résultats pour les batteries C/LFP et LTO/LFP avec une réduction du temps de charge total d'environ 70% par rapport à la méthode classique. Néanmoins, cette méthode présente des inconvénients comme notamment l’élévation de la température interne de la batterie pendant la charge rapide. De plus, cette méthode implique un courant élevé et conduit à des potentiels élevés qui peuvent engendrer également des dégradations. En particulier, nous avons démontré que la batterie C / LFP subissait des dégradations internes notamment une déformation mécanique de l’enroulement et une dégradation de la composition d’électrolyte. / The aim of this thesis is to study fast-charging of lithium-ion, battery using the ohmic-drop compensation method. The latter method theoretically will reduce the total charging of the batteries considered. In this thesis, the ODC method was implemented on three different types of 18650 battery cells. These batteries are C/LFP, C/NMC and LTO/LFP. This method show a good result for C/LFP and LTO/LFP batteries with a reduction of total charging time of about 70% in comparison with the classical method. Nevertheless, there are some issues regarding this method; the temperature elevation of the battery is high during fast-charging. Indeed, almost all fast-charging procedure experiences the same problem concerning that matter. Moreover, with ODC fast-charging method, high current rate and high voltage will worsen the situation. These complications of the ODC fast-charging method are key points for both performance and durability of the batteries. Particularly, we have demonstrated that C/LFP battery underwent internal degradation as a mechanical deformation of the active materials and degradation of electrolyte.

Abstract Background: The popularity of stocks in Sweden is high and with the prevailing low interest climate investors must invest in stocks to earn return on their investment. Achieving a higher return than the market has been a continuous struggle for professional as well as private investors. Having an investment strategy is of great importance because it helps the investor make rational decisions, avoid psychological traps, and prevents them from losing out on possible return. Investing in securities with different characteristics diversifies the portfolio and reduces the total risk taken. Therefore, an interest among investors in examining whether multiple valuation is a fitting investment strategy should exist. Further to examine if there are any multiples that are especially suited for specific branches. Purpose: The purpose of the study is to analyze which multiple of P/E, P/BV, EV/S and EV/EBITDA generates the highest risk-adjusted return through relative valuation within six branches on the Stockholm Stock Exchange. The study also aims to analyze whether high or low multiples generates the highest risk adjusted return in a Bull Market and try to explain why. Method: Too achieve the purpose, a quantitative study with an abductive approach has been used. An analysis of historical stock prices and multiples has been made. A total of 48 portfolios have been constructed including high respectively low P/E, P/BV, EV/S and EV/EBITDA multiples. The portfolios have been weighted on a yearly basis and afterwards compared with several risk-adjustment tools. The risk-adjusted return has thereafter been compared to a general index too make it possible to draw conclusions. Result: The result implies that it is statistically assured that investors can achieve a higher return than index by using multiple valuation as an investment strategy in four out of six examined branches. A difference in return among the branches and portfolios can be concluded and there were in total 18 out of 48 portfolios that showed a higher risk-adjusted return in which twelve were statistically assured. statistically assured higher return than the chosen index. Keywords: Multiple Valuation, Relative Valuation, Branches, P/E, P/BV, EV/S, EV/EBITDA, Stock Market Psychology, Bull Market.

This thesis deal with extended EV-55 version concept according to CS/FAR- 23 Commuter category specifications. Thesis objectives are design weights determination, mass analysis, calculation of aeroplane performances and comparison of aeroplane performances with current aeroplane.