Background. At the year of 2021, 770 million people worldwide were living without access to electricity. In parallel with this, electrification of vehicles and other equipment constantly increases which results in a demand for access to reliable off-grid energy to allow for operation in remote locations or places without sufficient energy infrastructure due to external factors such as natural disasters. As the use of fossil fuels is predicted to decrease, the need for sustainable energy production utilizing renewable energy sources has proved to be critical. The combination of these factors results in a need for the development of sustainable off-grid energy systems utilizing renewable energy sources.  Objectives. The objective of this thesis is to highlight needs and present a developed solution to portable off-grid energy production and distribution utilizing renewable energy sources. The goal is to highlight problems within the area of focus and present a potential solution to one, or multiple, of these problems. The presented solution shall be based on a solid engineering foundation and meet the technical requirements developed from needs that arise during the project. Methods. The work presented in this thesis was conducted with the use of DRM, Design Research Methodology, as the choice of research methodology while Design thinking was the choice of design approach. The use of DRM allowed for a structured and efficient research process that allowed for the possibility to validate result. The use of Design thinking as design approach provided methods and tools to support innovation while working with problems that were initially unknown or vaguely defined. Results. The result of the work presented in this thesis provides information regarding multiple problems and critical aspects within the area of focus. A list of requirements for a sustainable energy system to satisfy in order to enter the market is presented, where portability, reliability and redundancy are marked as key requirements. A proposed solution in the form of a portable modular sustainable energy production trailer utilizing different renewable energy sources was developed to allow for off-grid electricity generation. This combined with an energy distribution solution in the form of a energy storage module mounted on the Volvo TA15 system allows for autonomous energy transportation to the location of the energy need.  Conclusions. As the need for sustainable energy constantly increases, development of sustainable energy production and distribution systems that can operate off-grid has proven to be critical. The utilization of renewable energy sources has also been identified as a critical factor in parallel with the phasing out of fossil fuels. The proposed solution has provided evidence of the potential for a portable off-grid hybrid energy system and its potential impact on the global 2030-agenda goals for sustainability.

The mass-market adoption of electrification in the transportation sector mandates stringent and aggressive requirements in terms of cost, power rating, efficiency, power density, and specific density of power electronics. Modular packaging of power electronics is advantageous and thus ubiquitously used by the automotive industry. A trend of shrinking die sizes and increased integration is evident and will inevitably continue. The thermal management system has become ever more significant as it is one of the main obstacles to higher power densities. The cooling system must be cost-effective, simple, efficient, reliable, and compatible with system requirements. Pin fins are a reliable and effective means of augmenting heat transfer. They rely on inducing turbulence, increasing the effective wetted surface, and accelerating fluid velocity. Unavoidably the pin fin array also produces an undesirable pressure drop that is commensurate to the pumping power required for the system. In this thesis, a tool is developed for the geometry optimization of pin fin arrays to dissipate the heat at a rate large enough to ensure junction temperatures do not exceed the maximum value possible at a minimal pressure drop. It is hoped that this tool would contribute to the multi-physics optimization and integration of power electronics for electrified vehicles. This optimization is confined to equalaterally spaced short pin fins, aspect ratios less than three. The tool employs empirical correlations since flow is too complex to solve analytically and numerical solutions or CFD-simulations are too time and computationally extensive. The tool development is done in a comprehensive manner. Starting from the first principles of a two-level voltage source inverter's operation. Next, the inevitable power losses from the operation are explained and a method for their calculations is presented. Correlations in the literature related to both pressure drop and heat transfer are reviewed afterward. Then the methodology of the construction of the tool is explicated in detail. Employing a commercial power module to benchmark results; three scenarios with different flow rates and inlet temperatures are optimized for. Simulations in ANSYS Fluent are run to verify the accuracy of correlations used in the tool. Comparing the optimized geometry of pin fins to the original benchmarking geometry it is evident that employing this tool on a per-application basis provides superior performance. / Thesis / Master of Applied Science (MASc)

In this thesis, integrated active filter auxiliary power modules (AFAPMs) is presented in electrified vehicle applications. A topological evaluation is conducted particularly for the auxiliary power module (APM) applications in the electrified vehicles. Several primary and secondary base topologies are compared in terms of VA rating and performance. Multiple input/output topology configurations are compared with different connection configurations and control schemes. The MOSFET loss analysis is given. Based on the MOSFET loss analysis, the modular full bridge current doubler with input-series-output-parallel configuration presents better performance in terms of the switch efficiency and cost analysis. Bulk capacitor banks occupy large volume and impact the reliability in the traction inverter and HV battery charger in the vehicle applications. A capacitor-less design is relatively urgent for the next generation electrified vehicle. Active filter (AF) is one potential solution to reduce the corresponding dc-link capacitance. However, additional components are required which increases the system complicity and decreases its reliability. Hence, it would be great to integrate the AF into the LV battery charger for the vehicle applications. Based on the power switch requirements, the AFAPM is evaluated for traction inverter and HV battery charger, respectively. The evaluation result shows that the AFAPM for the HV battery charger system is a feasible and attractive solution. Furthermore, a simple and effective dual-mode dual-voltage charging system operating principle is proposed. The integrated AFAPM converter charges the LV battery when the vehicle is running and operates as an AF when the vehicle is connected to the grid and the HV battery is charging. Hence, the low-frequency second-order harmonic current is alleviated without a bulk capacitor bank or an extra AF circuit in the HV battery charger. For magnetic design, there is a trend toward integration and planarization. Two planar transformers are built for two different AFAPM prototypes. A minimized leakage inductance method is presented and implemented on a 20:1 center-tapped planar transformer. Three different integrated AFAPM converters are proposed. By applying these AFAPM converters, the required extra components to form the AF for the HV battery charger are reduced and thus the cost, size and weight for the dual-voltage charging system in the electrified vehicle applications can be reduced. Two prototypes are built. The experiments show promising results confirming the effectiveness of the proposed converters. / Dissertation / Doctor of Philosophy (PhD)

Over the past few years, electric propulsion systems have been widely used in automotive applications. The next decade is likely to see the electrification of aerial vehicles. In the past 20 years, the passengers demand in the aviation industry has increased by roughly 5% annually. Drastic increment in the passengers demand leads to many problems such as emission, noise pollution, airports capacity shortage, and high fuel consumption. An electric airplane that can take off and land in an extremely short runway can solve all the mentioned problems. Also, an airplane that is smaller and lighter with the ability to take off and land from an extremely short runway can be used as a new transportation system in congested cities and solve the urban road traffic and compensate for people’s time wasted in traffic. With this in mind, in this thesis, the feasibility of converting a conventional fixed-wing direct-drive propeller airplane to an electric extremely short takeoff and landing airplane has been examined. An overview of the history of electric aerial vehicles and flying cars is conducted where some of these vehicles are still under development phase. The main aim of this thesis is to address the effect of takeoff and landing runway length on the electric motor main specifications, including power, torque, and speed. Also, the effect of cruising speed on the motor specifications are investigated, and it is observed that there is a considerable difference between the amount of required power for the cruising mode and takeoff mode. In the end, the impact of the braking system and airplane weight on the landing distance are examined, and It is found that for an airplane with a cruise-efficient propeller, usage of thrust reverser is not practical and hence it is not recommended. Although if the propeller is designed to have high efficiency at takeoff and landing, the thrust reverser can be a good solution to make the landing runway shorter. / Thesis / Master of Applied Science (MASc)

Given the promise of the Inductive Power Transfer (IPT) technology for eRoad applications, the potential challenges for a successful integration of dynamic IPT technology into the physical road structure are explored extensively in this research work. The Finite Element Method (FEM) is selected for studying the structural performance of an eRoad under operational conditions. In this, an energy-based finite strain constitutive model for asphalt materials is developed and calibrated, to enable the detailed investigation of the structural response and optimization of the considered eRoad. In the context of enabling both dynamic charging and autonomous driving for future electric vehicles, the influences to the pavement (rutting) performance by the changed vehicle behaviour are investigated as well. Moreover, to study the effect on the IPT system by the integration, the potential power loss caused within eRoad pavement materials is further examined by a combined analytic and experimental analysis. The direct research goal of this Thesis is therefore to enhance the possibility of a sustainable implementation of the eRoad solutions into the real society. At the same time, it aims to demonstrate that the road structure itself is an important part of smart infrastructure systems that can either become a bottleneck or a vessel of opportunities, supporting the successful integration of these complex systems. / Givet de förutsättningar som induktiv energiöverföring (IPT Inductive Power Transfer) har för eRoad applikationerna, utforskas möjligheterna för en framgångsrik integration av dynamisk IPT i den fysiska vägkonstruktionen på en djupgående nivå i detta forskningsarbete. Speciellt har finita elementmetoden använts för att studera det strukturella beteendet hos en e-väg under driftsmässiga förhållanden. Inom detta har en energibaserad konstitutiv model för stora töjningar utvecklats och kalibrerats för att möjliggöra detaljerade undersökningar av strukturell respons och optimering av de föreslagna e-vägarna. I samband med att möjliggöra både dynamisk laddning och autonom körning för framtida elektriska fordon, har beläggningars (spårbildnings)egenskaper studerats utifrån de laddande fordonen beteende. Dessutom för att studera effekten av IPT-systemet har den potentiella energiförlusten inom e-vägars beläggningsmaterial undersökts genom en kombinerad analytisk och experimentell undersökning. Som sådant är det direkta forskningsmålet med denna avhandling att utöka möjligheterna för en hållbar implementering av eRoad systemet inom det verkliga samhället. Samtidigt är målet att visa att vägkonstruktionen i sig själv är en viktig del av det smarta infrastruktursystemet som antingen kan bli en flaskhals eller en bärare av möjligheter, stödjande en framgångsrik implementering av dessa komplexa system. / <p>QC 20161108</p>

Global sustainability awareness and governmental regulations are pushing the automotive industry into finding alternatives to carbon dioxide emitting products. Solutions utilizing electricity in the vehicle powertrain is overtaking market share from internal combustion engines (ICE). This tendency has spread into the heavy-duty truck segment which poses questions regarding the future of the ICE. An alternative, electric motors, powered with batteries, fuel cells of even ICE’s, is thought to become a core part of future mobility. To mitigate discontinuities during a shift from ICE to electric motors, a study of possible factors affecting such transition has been performed. The result indicates 14 main factors which are thought to have a definite role in a major technology paradigm shift. These factors are: Supplier relations, Material management, Material availability, Available space, Scalability, Product flexibility, Risk management, External resource utilization, Internal relations, Demand estimation, Management endorsement, Appropriate methodology, Employee engagement, and Competence renewal. A structure using ISM methodology is established highlighting the factors’ influencing relation to each other. Anchored in the theory regarding paradigmatic shifts within industry, a tendency of technological, managerial, and institutional influence on organizational change can be discerned where the institutional level poses as the fundamental dimension of derived quality. The factors are identified from a Scania specific case but are broad enough to apply to similar situations facing challenges of a technological paradigm shift.

Electrified vehicles (EVs) with a large electric energy storage system (ESS), including Plug-in Hybrid Electric Vehicles (PHEVs) and Pure Electric Vehicles (PEVs), provide a promising solution to utilize clean grid energy that can be generated from renewable sources and to address the increasing environmental concerns. Effectively extending the operation life of the large and costly ESS, thus lowering the lifecycle cost of EVs presents a major technical challenge at present. A hybrid energy storage system (HESS) that combines batteries and ultracapacitors (UCs) presents unique energy storage capability over traditional ESS made of pure batteries or UCs. With optimal energy management system (EMS) techniques, the HESS can considerably reduce the frequent charges and discharges on the batteries, extending their life, and fully utilizing their high energy density advantage. In this work, an intelligent energy allocation (IEA) algorithm that is based on Q-learning has been introduced. The new IEA method dynamically generate sub-optimal energy allocation strategy for the HESS based on each recognized trip of the EV. In each repeated trip, the self-learning IEA algorithm generates the optimal control schemes to distribute required current between the batteries and UCs according to the learned Q values. A RBF neural networks is trained and updated to approximate the Q values during the trip. This new method provides continuously improved energy sharing solutions better suited to each trip made by the EV, outperforming the present passive HESS and fixed-cutoff-frequency method. To efficiently recognize the repeated trips, an extended Support Vector Machine (e-SVM) method has been developed to extract significant features for classification. Comparing with the standard 2-norm SVM and linear 1-norm SVM, the new e-SVM provides a better balance between quality of classification and feature numbers, and measures feature observability. The e-SVM method is thus able to replace features with bad observability with other more observable features. Moreover, a novel pattern classification algorithm, Inertial Matching Pursuit Classification (IMPC), has been introduced for recognizing vehicle driving patterns within a shorter period of time, allowing timely update of energy management strategies, leading to improved Driver Performance Record (DPR) system resolution and accuracy. Simulation results proved that the new IMPC method is able to correctly recognize driving patterns with incomplete and inaccurate vehicle signal sample data. The combination of intelligent energy allocation (IEA) with improved e-SVM feature extraction and IMPC pattern classification techniques allowed the best characteristics of batteries and UCs in the integrated HESS to be fully utilized, while overcoming their inherent drawbacks, leading to optimal EMS for EVs with improved energy efficiency, performance, battery life, and lifecycle cost. / Graduate

Municipal energy systems in Nordic environments face multiple challenges: the cold climate, large-scale industries, a high share of electric heating and long distances drive energy consumption. While actions on the demand side minimize energy use, decarbonization efforts in mining, industries, the heating and the transport sector can increase the consumption of electricity and biofuels. Continued growth of intermittent wind and solar power increases supply, but the planned phase out of Swedish nuclear power will pose challenges to the reliability of the electricity system in the Nordic countries. Bottlenecks in the transmission and distribution grids may restrict a potential growth of electricity use in urban areas, limit new intermittent supply, peak electricity import and export. Environmental concerns may limit growth of biomass use. Local authorities are committed in contributing to national goals on mitigating climate change, while considering their own objectives for economic development, increased energy self-sufficiency and affordable energy costs. Given these circumstances, this thesis investigates existing technical and economic potentials of renewable energy (RE) resources in the Nordic countries with a focus on the northern counties of Finland, Norway and Sweden. The research further aims to provide sets of optimal solutions for sustainable Nordic municipal energy systems, where the interaction between major energy sectors are studied, considering multiple objectives of minimizing annual energy system costs and reducing carbon emissions as well as analyzing impacts on peak electricity import and export. This research formulates an integrated municipal energy system as a multi-objective optimization problem (MOOP), which is solved by interfacing the energy system simulation tool EnergyPLAN with a multi-objective evolutionary algorithm (MOEA) implemented in Matlab. In a first step, the integration or coupling of electricity and heating sectors is studied, and in a second step, the study inquires the impacts of an increasingly decarbonized transport sector on the energy system. Sensitivity analysis on key economic parameters and on different grid emission factors is performed. Piteå (Norrbotten County, Sweden) is a typical Nordic municipality, which serves as a case study for this research. The research concludes that significant techno-economic potentials exist for the investigated resources. Optimization results show that CO2 emissions of a Nordic municipal energy system can be reduced by about 60% without a considerable increase in total energy system costs and that peak electricity import can be reduced by up to 38%. The outlook onto 2030 shows that the transport sector could be composed of high electrification shares and biofuels. Technology choices for optimal solutions are highly sensitive to electricity prices, discount rates and grid emission factors. The inquiries of this research provide important insights about carbon mitigation strategies for integrated energy sectors within a perspective on Nordic municipalities. Future work will refine the transport model, develop and apply a framework for multi-criteria decision analysis (MCDA) enabling local decision makers to determine a technically and economically sound pathway based on the optimal alternatives provided, and analyze the existing policy framework affecting energy planning of local authorities. / Kommunala energisystem i nordiska miljöer möter flera utmaningar: det kalla klimatet, storskaliga industrier, en stor andel elvärme och långa distanser driver energiförbrukningen. Medan åtgärder vidtas på efterfrågesidan för att minimera energianvändningen, kan utsläppsminskande åtgärder inom gruvdrift, industrier, uppvärmningen och transportsektorn öka förbrukningen av el och biobränslen. Fortsatt tillväxt av intermittent vind- och solkraft ökar elproduktion, men den planerade avvecklingen av svensk kärnkraft kommer att utmana tillförlitligheten i elsystemet i de nordiska länderna. Flaskhalsar i överförings- och distributionsnäten kan begränsa en potentiell tillväxt av elanvändningen i stadsområden, begränsa ny intermittent utbud, och påverka elutbyte mellan länderna. Miljöhänsyn kan begränsa ökad användning av biomassa. Lokala myndigheter är engagerade i att bidra till nationella klimatmål, samtidigt som de följer sina egna mål för ekonomisk utveckling, ökad självförsörjning av energi och överkomliga energikostnader. Mot bakgrund av dessa omständigheter undersöker denna avhandling befintliga tekniska och ekonomiska potentialer för förnybar energi i Norden med fokus på de nordliga länen i Finland, Norge och Sverige. Forskningen syftar vidare till att utveckla optimala lösningar för hållbara nordiska kommunala energisystem, där samspelet mellan stora energisektorer studeras, med tanke på att minimera årliga energisystemkostnader och samtidigt minska koldioxidutsläppen samt analysera påverkan på elimport till och export från kommunen. Denna forskning formulerar ett integrerad kommunalt energisystem som multimåloptimeringsproblem (multi-objective optimisation problem - MOOP), som löses genom att kombinera simuleringsverktyget EnergyPLAN med en evolutionär algoritm implementerad i Matlab. I ett första steg studeras kopplingen av el- och värmesektorerna, och i ett andra steg effekterna av en integrerad och alltmer förnybar transportsektor på energisystemet. Känslighetsanalys på viktiga ekonomiska parametrar och på olika utsläppsfaktorer utförs. Piteå (Norrbottens län, Sverige) är en typisk nordisk kommun som fungerar som en fallstudie för detta arbete. Forskningens slutsatser innebär att det finns betydande teknisk-ekonomiska potentialer för de undersökta förnybara resurserna. Optimeringsresultaten visar att koldioxidutsläppen från ett nordiskt kommunalt energisystem kan minskas med cirka 60% utan en avsevärd ökning av de totala energisystemkostnaderna och att den högsta elimporten kan minskas med upp till 38%. Resultat för år 2030 visar att transportsektorn kan ha en mycket hög elektrifieringsgrad och samtidigt används biobränslen i tunga fordon. Optimala lösningar är mycket känsliga för elpriser, räntor och utsläppsfaktorer. Detta arbete ger viktiga insikter om strategier för koldioxidminskning för integrerade energisektorer i ett perspektiv på nordiska kommuner. Min framtida forskning kommer att förfina transportmodellen, utveckla och tillämpa ett ramverk för beslutsanalys med flera kriterier (multi-criteria decision analysis - MCDA) som ska stödja lokala myndigheter att fastställa tekniskt och ekonomiskt hållbara lösningar i deras energiplanering.

In an age where sustainability and reduced carbon dioxide emissions are highly prioritized, the transport sector faces one of its biggest challenges. Namely, reducing the environmental impact of heavy transport. In the search for solutions to make heavy transport more sustainable, electric roads and stationary charged trucks have emerged as promising alternatives. By replacing diesel trucks with electric alternatives, the solutions offer environmental benefits and contribute to Sweden's longer-term ability to achieve its climate goals. Increasing the speed of change is critical to accelerating the implementation of electrification and maximizing its positive effects on the environment and society. Therefore, it is of great interest to investigate the factors that influence the conversion process, as well as identify strategies and measures to promote a faster transition to electrified heavy transports.With this background, this study aims to investigate conditions and challenges for increasing the conversion rate of heavy transports. The study aims to gain a better understanding of the haulage companies' needs and preferences regarding the transition. Through semi-structured interviews with respondents from ten companies with varying needs, the results could be obtained, and several insights into the research question could be obtained. The analysis of the interviews, using Rogers' theory regarding the diffusion of innovation, gave rise to several barriers and driving forces for the change. The conditions that need to be created to increase the speed of the transition have then been based on the barriers and the respondents' answers. The results indicate that the speed of conversion to the electrification solutions in Sweden is controlled by the speed of adoption of the newly introduced technologies. Adoption, in turn, is affected by a series of driving forces and barriers. It is the barriers that prevent haulers from adopting the solutions. For electric roads, it has been established that the solution may be less interesting depending on the type of traffic that a company conducts. There is also uncertainty about whether electric roads will be built. Increased communication efforts by the authorities are required to spread knowledge about electric roads and address the uncertainty of potential users. When it comes to stationary charging, an electrified truck needs to achieve cost neutrality compared to a diesel truck. This can be achieved through financial support for the expansion of the charging infrastructure, subsidies, and financing services such as leasing. An additional prerequisite for increasing the adoption rate is forecasts and guarantees regarding electricity supply and electricity prices in the future. The technology for stationary charging needs to be developed further to meet the varying needs of companies in the market. The needs regarding the technology may differ from one company to another depending on the type of traffic and the goods being delivered. In order to speed up the conversion of the heaviest transports over 60 tons, the vehicles need to have reliable battery capacity. It is also necessary to offer a well-developed charging infrastructure to facilitate the electrification of all three types of transports, namely local, regional, and long-distance transport. Furthermore, knowledge-raising efforts by the authorities are required to counteract uncertainties regarding policies and future solutions. This study suggests initiatives such as the “effektkommissionen” of Region Skåne as a suitable communication channel between the actors involved. The initiative has the potential to address various uncertainties and make the solution more visible to potential users. By creating the proposed conditions, an increased rate of adoption can be achieved, which in turn, leads to Sweden fulfilling its climate goals. / I en tid där hållbarheten och minskade koldioxidutsläpp är högt prioriterade står transportsektorn inför en av sina största utmaningar, nämligen att minska miljöpåverkan från tunga transporter. I jakten på lösningar för att göra tunga transporter mer hållbara, har elvägar och stationärt laddade lastbilar framträtt som ett lovande alternativ. Genom att ersätta diesellastbilar med eldrivna alternativ erbjuder elektrifieringslösningarna betydande miljöfördelar, samt bidrar till att Sverige på längre sikt kan uppnå sina klimatmål. Att öka omställningshastigheten är avgörande för att påskynda implementeringen av elektrifieringen, samt maximera dess positiva effekter på miljön och samhället. Därför är det av stort intresse att undersöka faktorerna som påverkar omställningsprocessen, samt identifiera strategier och åtgärder för att främja en snabbare övergång till elektrifierade tunga transporter. Mot bakgrund av detta syftar denna studie till att undersöka möjliga förutsättningar och utmaningar för att öka omställningshastigheten för tunga transporter. Denna studie ämnar till att få bättre förståelse för åkeriföretagens behov och preferenser kring omställningen. Genom semistrukturerade intervjuer med respondenter från tio företag av varierande behov kunde resultaten erhållas och flera insikter på forskningsfrågan kunde fås. Analysen av intervjuerna med hjälp av Rogers teori kring diffusion av innovation gav upphov till flera barriärer och drivkrafter för omställningen. Förutsättningarna som behöver skapas för att öka omställningshastigheten har sedan baserats på barriärerna och respondenternas svar. Resultaten tyder på att omställningshastigheten till elektrifieringslösningarna i Sverige styrs utav adoptionshastigheten av dem nyintroducerade teknologierna. Adoptionen i sin tur påverkas av en rad drivkrafter och barriär. Det är framför allt barriärerna som utgör hindren för åkeriernas adoption av lösningarna. För elvägar har det konstaterats att lösningen kan vara en mindre intressant lösning beroende på typen av trafik som ett företag utför. Det råder dessutom en osäkerhet kring huruvida elvägar kommer att byggas. Det krävs ökade kommunikations insatser av myndigheterna för att sprida kunskaperna om elvägar och adressera osäkerheten hos potentiella användare. När det gäller stationär laddning behöver en elektrifierade lastbil uppnå kostnadsneutralitet jämför med en diesellastbil. Detta kan uppnås genom ekonomiskt stöd till utbyggnaden av laddinfrastrukturen, subventioner samt finansieringstjänster som leasing. En ytterligare förutsättning för att öka adoptionen är prognoser och garantier gällande elförsörjningen samt elpriserna i framtiden. Teknologin för stationär laddning behöver utvecklas vidare för att möta företagens varierande behov i marknaden. Behoven när det gäller teknologin kan skilja sig från ett företag till ett annat beroende på typen av trafik samt godsen som levereras. För att påskynda omställningen av de tyngsta transporterna över 60 ton behöver fordonen ha en tillförlitlig batterikapacitet. Det är dessutom nödvändigt att erbjuda en väl utbyggd laddinfrastruktur för att möjliggöra elektrifieringen av samtliga tre typer av transporter, nämligen lokal, regional, och fjärrtransporter. Vidare krävs kunskapshöjande insatser av myndigheterna för att motverka osäkerheter gällande styrmedel och framtida lösningar. Denna studie föreslår initiativ såsom effektkommissionen av Skåne Region som en lämplig kommunikationskanal mellan de involverade aktörerna. Initiativet har potentialen att adressera olika osäkerheter och göra lösningen mer synlig. Genom att skapa de föreslagna förutsättningarna kan en ökad omställningshastighet uppnås vilket i sin tur leder till att Sverige uppfyller sina klimatmål och ambitionen om att vara ett föregångsland.

Technology advancements enable and encourage higher system electrifications in various applications. More electrified applications need more capable and higher performing sources of energy in terms of power delivery, power regeneration, and energy capacity. For example, in electric, hybrid electric, and plug-in hybrid electric vehicle applications (EVs, HEVs, and PHEVs), the power and energy ratings of the vehicle energy storage system (ESS) have a direct impact on the vehicle performance. Many researchers investigated and studied various aspects of hybrid energy storage systems (HESS) wherein multiple ESSs are combined together to share system loads, increase ESS capabilities, and cycle life. Various configurations and their application specific topologies were also proposed by other researchers; the potential of HESS has been proven to be very promising. In this research, the goal is to present the theory of a HESS configuration that has not been discovered thus far. This HESS configuration is called a series-parallel reconfigurable HESS (SPR-HESS) since it is capable of recombining multiple storage systems into different series, parallel, or series-parallel configurations, via power electronic converters, to accommodate different operation modes and load requirements. Simulations, as well as experimental verifications, are presented in this thesis. / Thesis / Doctor of Philosophy (PhD)