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Frequency control coordination among non-synchronous AC areas connected by a multi-terminal HVDC grid. / Coordination du réglage de la fréquence entre plusieurs systèmes électriques non-synchrones reliés par un réseau à courant continu haute tensionDai, Jing 03 October 2011 (has links)
Cette thèse se focalise sur le problème du contrôle des flux de puissance entre plusieurs systèmes électriques AC non-synchrones reliés par un réseau à courant continu (DC). Elle propose trois schémas de commande afin de permettre aux sous-systèmes de partager leurs efforts de réglage de la fréquence et réduire ainsi le besoin de réserves propres et les coûts associés. A partir des mesures des fréquences de toutes les zones, le premier schéma de commande modifie les puissances injectées par chaque zone AC vers le réseau DC, de manière à faire réagir le système collectivement à des déséquilibres de charge. Cette réaction collective permet à chaque zone AC de réduire sa propre réserve primaire. Le deuxième schéma de commande a le même objectif que le premier, mais il agit sur les tensions continues des convertisseurs HVDC. En particulier, il modifie la tension continue de chaque convertisseur en fonction de la déviation de fréquence de la zone AC à laquelle il est connecté. Le dernier schéma de commande vise à rétablir les fréquences et les échanges de puissance à leurs valeurs nominales et prévues, respectivement, à la suite d'un déséquilibre. Il peut être combiné avec les deux autres schémas de commande. Des étudies théoriques démontrent les propriétés de stabilité des trois schémas de commande. Les résultats de simulation sur un réseau électrique de référence avec cinq zones AC illustrent leur bonne performance. / This thesis addresses the problem of frequency control in a power system composed of several non-synchronous AC areas connected by a multi-terminal HVDC grid. For this system, we propose three control schemes, two for primary frequency control and one for secondary frequency control. Based on remote measurements of the other areas' frequencies, the first control scheme modifies the power injections from the different AC areas into the DC grid so as to make the system collectively react to load imbalances. This collective reaction allows each individual AC area to downscale its primary reserves. The second control scheme has the same objective with the first one, but acts on the DC voltages of the HVDC converters. In particular, it modifies the DC voltage of each converter based on the frequency deviation of the AC area it is connected to. The last control scheme aims at restoring the frequencies and the power exchanges to their nominal or scheduled values in the aftermath of a power imbalance. It can be combined with the other two control schemes. Theoretical studies reveal the stability properties of the three control schemes. Simulation results on a benchmark power system with five AC areas confirm their good performance.
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Frequency control coordination among non-synchronous AC areas connected by a multi-terminal HVDC grid.Dai, Jing 03 October 2011 (has links) (PDF)
This thesis addresses the problem of frequency control in a power system composed of several non-synchronous AC areas connected by a multi-terminal HVDC grid. For this system, we propose three control schemes, two for primary frequency control and one for secondary frequency control. Based on remote measurements of the other areas' frequencies, the first control scheme modifies the power injections from the different AC areas into the DC grid so as to make the system collectively react to load imbalances. This collective reaction allows each individual AC area to downscale its primary reserves. The second control scheme has the same objective with the first one, but acts on the DC voltages of the HVDC converters. In particular, it modifies the DC voltage of each converter based on the frequency deviation of the AC area it is connected to. The last control scheme aims at restoring the frequencies and the power exchanges to their nominal or scheduled values in the aftermath of a power imbalance. It can be combined with the other two control schemes. Theoretical studies reveal the stability properties of the three control schemes. Simulation results on a benchmark power system with five AC areas confirm their good performance.
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Vertical Axis Wind Turbines : Electrical System and Experimental ResultsKjellin, Jon January 2012 (has links)
The wind power research at the division of Electricity at Uppsala University is aimed towards increased understanding of vertical axis wind turbines. The considered type of wind turbine is an H-rotor with a directly driven synchronous generator operating at variable speed. The experimental work presented in this thesis comprises investigation of three vertical axis wind turbines of different design and size. The electrical, control and measurement systems for the first 12 kW wind turbine have been designed and implemented. The second was a 10 kW wind turbine adapted to a telecom application. Both the 12 kW and the 10 kW were operated against dump loads. The third turbine was a 200 kW grid-connected wind turbine, where control and measurement systems have been implemented. Experimental results have shown that an all-electric control, substituting mechanical systems such as blade-pitch, is possible for this type of turbine. By controlling the rectified generator voltage, the rotational speed of the turbine is also controlled. An electrical start-up system has been built and verified. The power coefficient has been measured and the stall behaviour of this type of turbine has been examined. An optimum tip speed ratio control has been implemented and tested, with promising results. Use of the turbine to estimate the wind speed has been demonstrated. This has been used to get a faster regulation of the turbine compared to if an anemometer had been used.
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Critical evaluation of the battery electric vehicle for sustainable mobilityMilligan, Ross January 2017 (has links)
Can Battery Electric Vehicles replace conventional internal combustion engine vehicles for commuting purposes when exposed to a busy corporate activity within the city of Edinburgh? This thesis investigates the application of Battery Electric Vehicles (BEV) use in a commercial business environment in the city of Edinburgh, Scotland UK. The motivation behind this work is to determine if the Battery Electric Vehicle can replace conventional fossil fuel vehicles under real world drive cycles and the desire by many to combat the causes of climate change. Due to the nature of this work a significant part of the work will be underpinned by the quantitative methodology approach to the research. As the question indicates the research is supported by real live data coming from the vehicle both in proprietary data logging as well as reading and analysing the data coming from the vehicles own Electronic Control Unit (ECU).There will be mixed research methodology encompassing quantitative and qualitative research to obtain a complete response in respect to the management of the vehicle these methodologies will be the analysis of the measurable data as well as explorative, to gain the underlying reasons and motivations for choosing a battery electric vehicle as an option to the conventional vehicle for this type of application use.
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Um estudo da adaptabilidade dos sistemas eletrônicos de controle de malha fechada pelo sensor de oxigênio de motores ciclo Otto à gasolina ao receber álcool etílico hidratado como combustível alternativo / not availableArmando José Dal Bem 19 September 2003 (has links)
Traz um histórico da utilização do álcool como combustível no Brasil, mostrando suas vantagens ambientais, sociais e econômicas. Apresenta as propriedades físico-químicas do álcool etílico anidro e hidratado e suas reações de combustão, enfatizando a razão ar/combustível e comparando-o com a gasolina pura e a gasolina comercial brasileira. Utiliza as teorias existentes sobre motores de combustão interna quatro tempos, para demonstrar a influência da adição progressiva de álcool etílico hidratado na gasolina sobre o rendimento, torque, potência e consumo em um motor a gasolina. Utiliza o mesmo procedimento de análise para determinar a influência sobre os itens citados anteriormente, em um motor a gasolina operando com álcool etílico hidratado, sem sofrer alteração da taxa de compressão. Analisa a miscibilidade de misturas álcool etílico hidratado e gasolina. Descreve e analisa os resultados experimentais de rendimento, torque, potência e consumo de um motor a gasolina com sistema eletrônico de controle digital, operando com variadas proporções de mistura álcool etílico hidratado e gasolina, sem alteração de suas características originais. Repete o experimento anterior para o motor operando com álcool etílico hidratado com alteração das características originais da EPROM do sistema de controle eletrônico. / A historical approach to alcohol application as a fuel in Brazil is given, showing its environmental advantages and disadvantages. Physic-chemical properties of hydrous and anhydrous ethylic alcohol are presented, as well as its combustion reactions, emphasizing the ratio air/fuel and comparing it to pure gasoline and Brazilian commercial gasoline. Utilizes the existing theories about internal combustion motors in four times, to demonstrate the influence of progressive addition of hydrous ethylic alcohol in gasoline upon efficiency, torque, potency and consumption in a gasoline motor. Utilizes the same analysis procedure to determine the influence upon the previously cited items, in a gasoline motor, operating with hydrated ethylic alcohol, without suffering a compression rate alteration. Analyzes the miscibility of hydrous ethylic alcohol and gasoline mixture. Describes and analyzes experimental results of efficiency, torque, potency and consumption of a gasoline motor with a digitally controlled electric system, operating with varied proportions of hydrous ethylic alcohol and gasoline mixture, with no alteration in its original characteristics. Repeats the previous experiment with a motor operating with hydrous ethylic alcohol with alterations of the original characteristics in the electric control system EPROM.
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Um estudo da adaptabilidade dos sistemas eletrônicos de controle de malha fechada pelo sensor de oxigênio de motores ciclo Otto à gasolina ao receber álcool etílico hidratado como combustível alternativo / not availableDal Bem, Armando José 19 September 2003 (has links)
Traz um histórico da utilização do álcool como combustível no Brasil, mostrando suas vantagens ambientais, sociais e econômicas. Apresenta as propriedades físico-químicas do álcool etílico anidro e hidratado e suas reações de combustão, enfatizando a razão ar/combustível e comparando-o com a gasolina pura e a gasolina comercial brasileira. Utiliza as teorias existentes sobre motores de combustão interna quatro tempos, para demonstrar a influência da adição progressiva de álcool etílico hidratado na gasolina sobre o rendimento, torque, potência e consumo em um motor a gasolina. Utiliza o mesmo procedimento de análise para determinar a influência sobre os itens citados anteriormente, em um motor a gasolina operando com álcool etílico hidratado, sem sofrer alteração da taxa de compressão. Analisa a miscibilidade de misturas álcool etílico hidratado e gasolina. Descreve e analisa os resultados experimentais de rendimento, torque, potência e consumo de um motor a gasolina com sistema eletrônico de controle digital, operando com variadas proporções de mistura álcool etílico hidratado e gasolina, sem alteração de suas características originais. Repete o experimento anterior para o motor operando com álcool etílico hidratado com alteração das características originais da EPROM do sistema de controle eletrônico. / A historical approach to alcohol application as a fuel in Brazil is given, showing its environmental advantages and disadvantages. Physic-chemical properties of hydrous and anhydrous ethylic alcohol are presented, as well as its combustion reactions, emphasizing the ratio air/fuel and comparing it to pure gasoline and Brazilian commercial gasoline. Utilizes the existing theories about internal combustion motors in four times, to demonstrate the influence of progressive addition of hydrous ethylic alcohol in gasoline upon efficiency, torque, potency and consumption in a gasoline motor. Utilizes the same analysis procedure to determine the influence upon the previously cited items, in a gasoline motor, operating with hydrated ethylic alcohol, without suffering a compression rate alteration. Analyzes the miscibility of hydrous ethylic alcohol and gasoline mixture. Describes and analyzes experimental results of efficiency, torque, potency and consumption of a gasoline motor with a digitally controlled electric system, operating with varied proportions of hydrous ethylic alcohol and gasoline mixture, with no alteration in its original characteristics. Repeats the previous experiment with a motor operating with hydrous ethylic alcohol with alterations of the original characteristics in the electric control system EPROM.
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Investigation for the development of a new electric control unit for customized trucksLiu, Yusen January 2019 (has links)
Customized truck is a relevant and high-profit part of Scania’s market. Nowadaysdesigners do not have a self-developed electric control unit for introducing non-standardfunctionality. This thesis is intended to investigate the specification of a new system andan approach to implement it in current truck’s electrical system. The adopted methodsin this research are systems analysis, functional specification, HW & SW research andcomparison and validation test of prototype system. The results obtained in this researchinclude the potential functions and corresponding requirement specification, 5 types ofhardware alternatives and 2 recommended software platform. Their feasibility is verifiedby a prototype system with 2 typical functions, control the motor of inward sliding doorand combine the communication of different system. 3 recommended schemes and 2 directionsfor future research are given in the end. Based on investigation results, developersare able to know new system’s specification preliminarily, understand the architectural requirementsand suitable tools and materials for implementation. This research will helpto improve Scania’s truck’s electrical system and product manufacturing in the future. / Specialfordon utgör en viktig och betydande del av Scanias produkter. Dagens de-signer har inte tillgång till en egenutvecklad styrenhet för att introducera icke standardiserade funktioner. Detta examensarbete fokuserar på att undersöka ett nytt system och hur det skulle implementeras i den redan existerande lastbilens elektriska system. De behandlade ämnena i arbetet är systemanalys, funktionsanalys, hårdvaruspecifikation, mjukvara samt validering och utvärdering i form av byggnation och testning av en prototyp. Resultatet som erhållits i denna rapport inkluderar potentiella funktioner och motsvarande kravspecifikation, fem typer av hårdvara och tvårekommenderade mjukvaruplattformar. Reliabiliteten av dessa valideras med en prototyp med två typiska funktioner, kontrolleraen motor på en elektrisk dörr samt kombinera kommunikationen av olika system. Trealternativa lösningar samt två alternativ till framtida studier rekommenderas i slutet av rapporten. Baserat på resultaten har utvecklare möjlighet till en preliminär specifikation,förståkrav påarkitektur, användbara verktyg och material för implementation. Dennarapport kommer att underlätta förbättring av Scanias elektriska system och utveckling iframtiden.
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Electrical energy management of the vehicle network including electrified auxiliaries in HEV/PHEVs / Gestion d'énergie du réseau de puissance recevant les auxiliaires électrifiées dans les véhicules hybrides électriques et rechargeablesNguyen, Khoa Duc 08 January 2016 (has links)
Face à l'augmentation du prix du carburant et des exigences légales rigoureuses sur les émissions de gaz à effet de serre ces dernières années, les fabricants de camions doivent s'interroger davantage sur les nouvelles mesures techniques pour être plus compétitifs sur le marché. Dans ce contexte, l'électromobilité est l'une des approches les plus prometteuses pour répondre aux exigences ci-dessus, où sa solution principale est l'hybridation électrique du groupe motopropulseur. Parallèlement à cette solution, une autre solution technique de l'électromobilité, l'électrification auxiliaire qui apparaît récemment, devient aussi une solution attrayante non seulement pour le milieu universitaire, mais aussi pour les entreprises de l'automobile. Cependant, l'intégration de ces deux solutions dans un véhicule peut donner lieu à un problème de commande du système beaucoup plus compliqué, notamment en terme de gestion de l'énergie. L'objectif de ce travail est de concevoir une approche appropriée pour la conception de la commande auxiliaire électrifiée, qui peut gérer d'une part la stratégie de commande du groupe motopropulseur hybride électrique et, d'autre part, améliorer l'efficacité énergétique globale du véhicule. Tout d'abord, le travail se concentre sur un seul auxiliaire électrifié typique - le système d'alimentation en air. Pour ce cas simple, la modélisation et le contrôle à base d'énergie basés sur le contrôle prédictif (MPC) sont développés afin de minimiser la consommation d'énergie / l'efficacité de cet auxiliaire le long d'un cycle de conduite. En soulignant les difficultés à atteindre l'objectif en matière d'efficacité énergétique en considérant uniquement des unités auxiliaires, l'approche se concentre ensuite sur l'analyse d'impact du système auxiliaire sur l'efficacité énergétique globale du véhicule. La première étape de cette analyse propose une méthode générale pour simplifier le contrôleur de groupe motopropulseur de HEV / PHEVs. Ensuite, une méthode basée sur l'optimisation est présentée et appliquée sur un modèle de véhicule simplifié, qui contient le contrôleur de groupe motopropulseur simple obtenu à partir de l'étape ci-dessus. Cette méthode d'optimisation, qui est un contrôle en mode hors connexion et basée sur la méthode de programmation dynamique, permet de déterminer l'économie d'énergie maximale réalisable du véhicule lors de l'application d'une stratégie de contrôle avancée sur le système auxiliaire électrifié. De plus, certaines idées / règles pour concevoir le contrôle auxiliaire sont également tirées des résultats obtenus avec la méthode ci-dessus. Pour une mise en oeuvre en ligne de ces concepts, un contrôle multi-agent est finalement adopté pour la commande du système auxiliaire électrifié (EAS). Sur la base des résultats de l'étape d'analyse d'impact et d'un modèle simple de l'EAS, trois paramètres de contrôle pour l'EAS (centralisé, hiérarchisé et distribué) sont étudiés et discutés. Enfin, différents algorithmes pour ces paramètres de contrôle sont fournis, puis comparés pour indiquer les avantages et les limites de chaque algorithme. / Facing to the increase of fuel price and stringent legal requirements on the greenhouse gas emission in recent years, truck manufacturers have to investi-gate more on new technical measures to be more competitive on the market. Within this context, electromobility rises as one of the most promising approaches to answer to above requirements, where its principle solution is the electric hybridization of powertrain. In parallel with this solution, another technical solution of electromobility- the auxiliary electrification that appears recently becomes also an attractive solution for not only the academic community but also the automotive companies. However, the integration of these two solutions together in a vehicle can give rise to a much more complicated system control problem, especially in term of energy management. The objective of this work is to figure out an appropriate approach for designing the electrified auxiliary control, which can cope with the control strategy of the electric hybrid powertrain on one hand, and can improve the overall energy efficiency of the vehicle on the other hand. Firstly, the work focuses on only one typical electrified auxiliary- the air supply system. For this simple case, energy-based modeling and control based on predictive control (MPC) are developed in order to minimize the energy consumption/efficiency of this auxiliary along a driving cycle. By pointing out the difficulties for reaching the target on the energy efficiency when considering only auxiliary units, the approach focuses then on the impact analysis of the auxiliary system on the overall vehicle‘s energy efficiency. The first step of this analysis proposes a general method to simplify the powertrain controller of HEV/PHEVs. Then, an optimization-based method is presented and applied on a simplified vehicle model, which contains the simple powertrain controller obtained from the above step. This optimization method, which is an offline con-trol and based on the dynamic programming method, allows us to determine the maximal achievable energy saving of the vehicle when applying an advanced control strategy on the electrified auxiliary system. Additionally, some ideas/rules for designing the auxiliary control are drawn as well from the results obtained with the above method. Toward an online implementation of these concepts, a multi-agent based control is finally adopted for controlling the electrified auxiliary system (EAS). Based on the results of the impact analysis step and a simple model of the EAS, three control settings for the EAS (centralized, hierarchical, and distributed) are studied and discussed. Finally, different algorithms for these control settings are provided, and then compared to point out the advantages and limitations of each algorithm.
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Έλεγχος ισχύος και μοντελοποίηση αιολικού συστήματος με ασύγχρονη μηχανή διπλής τροφοδοσίας (DFIG)Κόρκα, Στυλιανή, Σιμώνη, Βασιλική 10 March 2014 (has links)
Η παρούσα διπλωματική εργασία πραγματεύεται την μελέτη και ανάλυση ενός αιολικού συστήματος με ασύγχρονη μηχανή διπλής τροφοδοσίας. Αρχικά, γίνεται μία εισαγωγή στις ανανεώσιμες πηγές ενέργειας, με ιδιαίτερη αναφορά στην αιολική ενέργεια. Κατόπιν, περιγράφονται τα κυριότερα ανεμολογικά χαρακτηριστικά οι διάφοροι τρόποι ταξινόμησης των ανεμογεννητριών που υπάρχουν σήμερα, τα δομικά στοιχεία αυτών, καθώς και οι βασικές τεχνικές ελέγχου που εφαρμόζονται σ’ αυτές. Ακολουθεί η γενική παρουσίαση μίας διπλά τροφοδοτούμενης επαγωγικής γεννήτριας. Προκειμένου να γίνει μελέτη των μεταβατικών καταστάσεων, παρουσιάζεται το δυναμικό μοντέλο και ο διανυσματικός έλεγχος μίας διπλά τροφοδοτούμενης επαγωγικής γεννήτριας διπλής τροφοδοσίας. Τέλος, γίνεται η προσομοίωση ενός αιολικού πάρκου, που περιλαμβάνει ανεμογεννήτριες αυτού του τύπου και μελετώνται τα δεδομένα που προκύπτουν για τυχαίες μεταβολές του ανέμου. / The subject of this thesis is the study and analysis of a variable speed wind turbine equipped with a doubly-fed induction generator (DFIG). At first, an introduction is made of the renewable energy sources, with special mention of the wind energy. Then, there is the description of the different types of wind turbines than exist nowadays, their components and their aerodynamic conversion. A general presentation of a doubly-fed induction generator (DFIG) is made. After that, the dynamic model and the vector control doubly-fed induction generator are presented in order to study various transition phenomena. Finally, the simulation of a wind farm that includes wind turbines of this type, is made and we study the effects of sudden changes of the wind speed.
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Contribution à la conception de driver en technologie CMOS SOI pour la commande de transistors JFET SiC pour un environnement de haute température / High temperature CMOS SOI driver for JFET SiC transistorsFalahi, Khalil El 25 July 2012 (has links)
Dans le domaine aéronautique, les systèmes électriques remplacement progressivement les systèmes de contrôle mécaniques ou hydrauliques. Les bénéfices immédiats sont la réduction de la masse embarquée et des performances accrues à condition que l’électronique supporte l’absence de système de refroidissement. Si la haute température de fonctionnement n’empêche pas d’atteindre une fiabilité suffisante, il y aura réduction des coûts opérationnels. Des étapes clefs ont été franchies en introduisant des systèmes à commande électriques dans les aéronefs en lieu et place de systèmes conventionnels : freins électriques, inverseur de poussée, vérins électriques de commandes de vol… Toutes ces avancées se sont accélérées ces dernières années grâce entre autre à l’utilisation de nouveaux matériaux semiconducteurs, dit à grand gap (SiC, GaN…), opérant à haute température et palliant ainsi une faiblesse des dispositifs classiques en silicium (Si). Des composants de puissance haute température, diode Schottky ou transistor JFET SiC, sont ainsi disponibles commercialement et peuvent supporter des ambiantes de plus de 220°C. Des modules de puissances (onduleur) à base de transistor JFET SiC ont été réalisés et validés à haute température. Finalement la partie « commande » de ces modules de puissance reste à concevoir pour les environnements sévères pour permettre leur introduction dans le module de puissance. C’est dans ce contexte de faiblesse concernant l’étage de commande rapprochée qu’a été construit le projet FNRAE COTECH, et où s’inscrivent les travaux de cette thèse, Dans un premier temps, un état de l’art sur les drivers et leurs technologies nous a permis de souligner le lien complexe entre électronique et température ainsi que le potentiel de la technologie CMOS sur Silicium sur Isolant (SOI) pour des applications hautes températures. La caractérisation en température de drivers SOI disponibles dans le commerce nous a fourni des données d’entrée sur le comportement de tels dispositifs. Ces caractérisations sont essentielles pour visualiser et interpréter l’effet de la température sur les caractéristiques du dispositif. Ces mesures mettent aussi en avant les limites pratiques des technologies employées. La partie principale de cette thèse concerne la conception et la caractérisation de blocs ou IPs pour le cœur d’un driver haute température de JFET SiC. Elle est articulée autour de deux runs SOI (TFSmart1). Les blocs développés incluent entre autres des étages de sortie et leurs buffers associés et des fonctions de protection. Les drivers ainsi constitués ont été testés sur un intervalle de température allant de -50°C à plus de 250°C sans défaillance constatée. Une fonction originale de protection des JFETs contre les courts-circuits a été démontrée. Cette fonction permet de surmonter la principale limitation de ces transistors normalement passant (Normaly-ON). Finalement, un module de bras d’onduleur a été conçu pour tester ces driver in-situ. / In aeronautics, electrical systems progressively replace mechanical and hydraulic control systems. If the electronics can stand the absence of cooling, the immediate advantages will be the reduction of mass, increased performances, admissible reliability and thus reduction of costs. In aircraft, some important steps have already been performed successfully when substituting standard systems by electrical control system such as electrical brakes, thrust reverser, electrical actuators for flight control… Large band gap semiconductors (SiC, GaN…) have eased the operation in high temperature over the last decade and let overcome a weakness of conventional silicon systems (Si). High temperature power components such as Schottky diodes or JFET transistors, are already commercially available for a use up to 220°C, limited by package. Moreover inverters based on SiC JFET transistors have been realized and characterized at high temperature. Finally the control part of these power systems needs to be designed for harsh environment. It is in this context of lack of integrated control part that the FNRAE COTECH project and my doctoral research have been built. Based on a state of the art about drivers, the complex link between electronic and temperature and the potentialities of CMOS Silicon-On-Insulator technology (SOI) for high temperature applications have been underlined. The characterization of commercial SOI drivers gives essential data on these systems and their behavior at high temperature. These measurements also highlight the practical limitations of SOI technologies. The main part of this manuscript concerns the design and characterization of functions or IPs for high temperature JFET SiC driver. Two SOI runs in TFSmart1 have been realized. The developed functions include the driver output stage, associated buffers and protection functions. The drivers have been tested from -50°C up to 250°C without failure under short time-range. Moreover, an original protection function has been demonstrated against the short-circuit of an inverter leg. This function allows overcoming the main limitation of the normally on JFET transistor. Finally, an inverter module has been built for in-situ test of these new drivers.
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