The world is quickly changing and the transition away from fossil fuels is occurring at a rapid pace. The car industry has experienced a radical change in the last years replacing combustion cars with electrical ones. The infrastructure to support the new vehicles with charging facilities has not met the demand in terms of accessibility and technical performance. Neither have the chargers reached a sustainable number to support the ever-increasing number of electric cars on the road. To adapt to this need companies have started to pursue next generation chargers. This paper focused on creating the next generation of chargers with visual design, interaction, and manufacturing as the focus point. This project is a collaboration with the company Zpark to create a new visual branding for their products and improve the user experience for their user group.  The project takes a wide approach to initial research, looking at both AC and DC chargers on the market as well as the user groups' current opinions. This research was implemented to create a DC charger (fast charging unit), as the company had not yet created a product that could cover this market segment. In the design process, a visual branding was created to make Zpark a more recognizable company. Several features were distinguished that could be implemented on future products in their line-up, whilst also creating the possibility of re-branding to specific buyers. A suggested manufacturing process and material choice were made to work as a guideline to create a more sustainable product, with ecological and economic impact as factors.  Four main categories of needs for the charger were elaborated on to create a better interaction, both for users charging and owners of the chargers. These four categories were charging, payment, communication, and maintenance. All the solutions help to create a more sustainable charging solution that will aid the transition to electric with a future-proofing aspect in mind.

In the era of ever-increasing electrification, power-electronic converters play the crucial role of transforming electrical energy from one form to another. However, converters today face multiple challenges in meeting ever-growing demands for higher power density, broader operation ranges, and lower costs. The cost-benefits of economies of scale further emphasize the need for modular and scalable converters. While no single converter for high-power applications satisfies all criteria, the modular multilevel converter (MMC) emerges as the clear frontrunner. MMC is extremely modular, being developed using multiple smaller units or building blocks called power electronic building blocks (PEBBs) or submodules (SMs). The SMs are themselves developed using fast-switching low-voltage (LV) semiconductors meaningfully combined with energy storage components like capacitors or batteries. MMCs are highly modular and scalable and have a very broad operation range, making them a key solution already used today for a wide range of high-voltage applications like high-voltage direct-current (HVDC) transmission. However, the use of voluminous and heavy capacitors in SMs also makes MMCs much lower in power density compared to other similar voltage source converters (VSCs). Employing at least twice the number of devices compared to a conventional two-level VSC for the same ratings also increases the converter costs. These challenges have hindered MMC applications in medium-voltage (MV) and more power-dense HVDC systems. This research aims to overcome these limitations by enhancing MMCs in terms of power density, efficiency, and cost-effectiveness. These modifications would expand MMC's applications to much broader HV and MV markets. Three fundamental aspects are targeted to achieve such improvements: Topology, Components, and Controls. The first modification focuses on changing the topology by replacing some fast-switching LV-switch-based SMs with fewer low-frequency HV/MV switches. This greatly reduces the total number of components and, when combined with intelligent control, decreases costs and losses. The second modification focuses on components, proposing the replacement of fully controlled MV switches with more efficient and cost-effective but partially controlled ones like thyristors. Despite thyristors' historical controllability challenges, incorporating SMs can help resolve control challenges, creating a modular, scalable converter with a wide operation range, high power density, and lower costs. The third avenue explores advanced control strategies while maintaining the traditional MMC topology. By accelerating and precisely controlling the capacitor current, the SM capacitor energy, SM capacitor size can be significantly reduced. Although these control methods are complex, they offer potential improvements across all five criteria: modularity, scalability, power density, cost, and operational range. These innovations extend MMCs' applicability to emerging fields such as energy storage systems, electric vehicle charging stations, motor drives, and data centers. Moreover, these modifications enhance MMCs for traditional high-voltage direct-current transmission applications. The research emphasizes the advantages and addresses each modification's limitations, paving the way for a more efficient and versatile power electronics technology. / Doctor of Philosophy / In our electrically powered world, the unsung workhorse is the power(-electronic) converter. Power converters play the crucial role of transforming electrical energy from one form to another using switches that can turn on and off to accurately control the flow of electrical energy. Power converters are critical to integrating systems at different voltage, current, and power ratings. For instance, power converters enable low-power systems like cellphone chargers and high-power industrial drives to be integrated into the same interconnected power grid. However, these converters face challenges in adapting to the evolving demands of our modern world. The expectations from power converters are high – they need to be affordable, lightweight, and capable of processing large amounts of power in a compact size. Additionally, modularity and scalability are desired qualities to enable economies of scale and bring the total cost down. Yet, finding a converter that fulfills all these criteria remains a challenge. The modular multilevel converter (MMC) is a promising power converter developed to address most of these considerations. Currently employed in high-power, high-voltage applications such as transmitting energy over vast distances or linking power grids between countries, the MMC is constructed using smaller power units or building blocks called power electronic building blocks (PEBBs) or submodules (SMs). These SMs utilize fast-switching low-voltage switches along with energy storage components like capacitors or batteries. Despite its versatility, the MMC faces many limitations. The main challenge for MMCs is the inability to process more power in lower volume, commonly referred to as power density. The MMC power density is low due to the use of large capacitors or batteries. Additionally, it utilizes twice the number of switches compared to traditional non-modular power converters for the same rating, leading to higher costs. These challenges restrict its application in medium-voltage and power-dense high-voltage high-power systems. This research aims to address these challenges, focusing on enhancing the power density and cost-effectiveness of MMCs. Three key areas of MMC are targeted for improvement: topology, components, and controls. Firstly, MMC's structure is reimagined, replacing many low-voltage switches with fewer medium- or high-voltage, fully-controlled switches. Such a system is referred to as a hybrid MMC, and this reduces the converter volume and costs. This adjustment has the added benefit of making the converter more efficient. Secondly, the focus is also on the components used to develop hybrid MMCs. Instead of fully controlled medium- or high-voltage switches, partially controlled switches like thyristors provide advantages like lower losses and higher power ratings. However, these partially controlled switches have traditionally been very difficult to control. Despite historical controllability challenges, incorporating these partially controlled switches in conjunction with smart control of SMs addresses control issues, creating a modular, scalable converter with high power density and lower costs. The third enhancement involves fundamental improvements to MMC controls. By managing the energy flow to the capacitor at a much faster rate and precision than conventional methods, the size of a critical component can be significantly reduced, opening avenues for overall improvements. Furthermore, such fast control introduces additional challenges like active control in the face of non-idealities and higher losses. This dissertation further meaningfully addresses these challenges to develop a much more power-dense MMC. These improvements transform the MMC and its variants into a versatile power converter family that can extend much beyond traditional MMC applications of high-voltage transmission applications. With these modifications, the MMC can be further positioned as an excellent candidate to contribute towards energy storage systems, electric vehicle charging stations, industrial-level motor drives, dc microgrids, and data centers, meeting the diverse needs of our equally diverse and ever-more electrified world.

La charge d’un véhicule électrique constitue un enjeu stratégique pour les constructeurs automobile et forme un réel défi à relever avant de pouvoir comparer ces véhicules à la simplicité d'usage du véhicule thermique. En effet, l’autonomie limitée, la durée de recharge de la batterie, le coût du déploiement d’une infrastructure de charge rapide, l'impact significatif sur les réseaux électriques et le coût élevé de la batterie sont à l’origine de plusieurs projets de recherche axés sur l’optimisation de la chaîne de recharge du véhicule électrique. Afin d’améliorer l'autonomie d'un véhicule électrique, une solution contraignante mais stratégique consiste à embarquer le chargeur dans le véhicule afin d’assurer la conversion ac-dc de l’énergie à partir des prises de courant. Cette solution permet d’augmenter la disponibilité de la charge pour les utilisateurs. En outre, le chargeur embarqué peut réutiliser tout, ou une partie des éléments déjà existants et nécessaires à la propulsion du véhicule. L'idée étant de pouvoir employer certains éléments de la chaîne de traction électrique, déjà embarqués dans le VE (moteur électrique et onduleur de tension), et d’ajouter un filtre d'entrée et un redresseur afin de concevoir le chargeur. Cette solution permet de réduire le coût du chargeur, sa taille ainsi que le volume nécessaire à l'intégration de ses constituants électriques, on parle alors de chargeur intégré à la chaîne de traction. Cependant, la réutilisation de l’électronique de puissance embarquée engendre des problèmes de compatibilité électromagnétique avec d’autres équipements connectés sur le réseau électrique et aussi avec les dispositifs de protection domestique.Le problème majeur à lever est donc, la limitation des émissions conduites et plus particulièrement des courants de mode commun dans une gamme de fréquence importante. Ce projet de thèse a donc, pour objectif, l’amélioration de la disponibilité de la charge actuelle tout en réduisant le volume du filtre CEM passif. Nous cherchons, à travers ces travaux, à identifier des domaines d'améliorations possibles, à proposer des solutions à bas coûts et à intégrer des modifications au niveau de la commande et de la topologie afin d'optimiser le comportement CEM, tant en basses fréquences (0 - 2 kHz) qu’en hautes fréquences (150 Hz- 30 MHz), de ce chargeur embarqué intégré sans isolation galvanique. Les propositions doivent répondre simultanément aux besoins de recharge domestique en monophasé (à 3.7 kW et à 7.4 kW) et rapide en triphasé (à 22 kW et à 43 kW) sans pour autant augmenter le volume ni les coûts engendrés. Ainsi, cinq axes de travail sont étudiés: l’optimisation du comportement CEM (0-2 kHz) du chargeur en monophasé ; l’optimisation du comportement CEM (0-2 kHz) du chargeur en triphasé ; le développement, la mise en œuvre et l’instrumentation de deux bancs expérimentaux exploités pour l’obtention de résultats; la proposition d’une approche de modélisation CEM de la structure qui tient compte du mode commun et du mode différentiel ; et la proposition de solutions pour la réduction des émissions conduites (150 kHz – 30 MHz). / Battery chargers for electric vehicles are classified as on-board or off-board chargers. Off-board chargers are not constrained by size or weight but introduce additional cost to the infrastructure through the deployment of a high number of charging stations. In order to meet the needs of electric vehicle users in terms of charging availability, on-board chargers that achieve ac/dc conversion are retained. Furthermore, on-board chargers are classified as standalone or integrated systems. By reusing parts of the traction power train for charging, the latter reduces the cost of the charger. Disadvantages of integrated systems include electromagnetic compatibility issues and complex control schemes.This work presents the power quality performance analysis and control optimization of an on-board non-galvanically isolated electric vehicle charger integrated to the traction’s power train. In order to be able to evaluate the high frequency conducted common mode emissions (150 kHz - 30MHz) of a power conversion structure, one needs to develop a good current control scheme that establishes a high-quality low frequency behavior (0 - 2 kHz). Therefore, different aspects related to the power factor correction of the single-phase as well as the three-phase charging configurations are studied: the control scheme for the regulation of the charging power, the displacement power factor correction, the suppression of the grid current harmonics and the active damping of the input filter’s resonance. Two experimental test benches are developed using two different technologies (Silicon IGBTs vs. Silicon Carbide Mosfets). Experimental results are provided.This work also presents a comprehensive approach to modeling the CM and the DM EMI behavior of a power electronics structure. This method is applied to the charger in its single-phase and three-phase configurations. The models allow to evaluate the fluctuating internal nodes and to study the effect of various proposed mitigation solutions on the CM emissions. The models are also developed in the intent of being injected into optimization algorithms for the future design of an optimal EMI filter.