Nos últimos 20 anos, o inversor de frequência PWM passou a ser largamente utilizado. Dentre as razões principais de sua ampla difusão, cita-se a introdução do IGBT que, devido à sua capacidade de comutação rápida, possibilitou a redução de perdas, tamanho e custo dos conversores, ao mesmo tempo em que permitiu o uso do motor de indução em aplicações que demandam alto desempenho dinâmico. Porém, esta mesma característica que trouxe tais benefícios, contribuiu para acentuar os efeitos relacionados a fenômenos eletromagnéticos, devido à rápida transição que produz sinais em alta frequência, responsáveis por tornar os sistemas de acionamentos potenciais fontes de interferência eletromagnética. Os principais fenômenos desta natureza são a tensão de onda refletida, associada a ruídos de modo diferencial, e a corrente de modo comum. De maneira geral, a corrente de modo comum tem maior potencial de contribuição para a emissão radiada que a de modo diferencial e, em sistemas de acionamento, constitui a principal fonte de interferência eletromagnética. Esta não é resultado apenas da rápida comutação dos IGBTs, mas, também, da configuração do sistema, que propicia o surgimento das tensões de modo comum. Este trabalho visa estudar alternativas que minimizem, naturalmente, estas tensões através de sua configuração, reduzindo-se a necessidade de novos componentes, como filtros passivos ou circuitos ativos. Ressalta-se, assim, que o primeiro passo consistiu-se na compreensão do problema de geração da tensão de modo comum. Visando atingir os propósitos anteriormente mencionados, foi idealizado um inversor, composto de duas pontes chaveando em oposição, chamado de duplo-trifásico. A partir de simulações, avaliou-se seu potencial e definiu-se sua implementação, a partir de dois inversores idênticos. Testou-se o protótipo contra um terceiro módulo de mesmo tipo, em iguais condições. A comparação dos resultados indicou que a configuração proposta pode ser eficiente no controle do ruído de modo comum, obtendo-se valores de redução de 86%. Nota-se que o comportamento observado via o protótipo, permite um melhor entendimento dos fenômenos relativos à circulação da corrente de modo comum. Desta forma, à luz da pesquisa realizada, nota-se que, conceitualmente, a solução proposta se destaca das demais apresentadas na literatura pela sua exequibilidade e simplicidade. / Over the last 20 years, the PWM frequency inverter has become widely used. Among the main reasons for its widespread distribution is the introduction of the IGBT, due to its ability for fast switching allowing the reduction of losses, size and cost of the converters, and the use of the induction motor in applications that demand high dynamic performance. However, this same characteristic that brought such benefits, stressed the effects related to electromagnetic phenomena, due to the fast transition that produces high frequency signals, responsible for turning drive systems, potential sources of electromagnetic interference. The main phenomena of this nature are the reflected wave overvoltage, associated with differential mode noise, and the common mode current. In general, the common mode current has greater potential of contribution to the emission of radiated interference than the differential mode current and is the main source of electromagnetic interference in drive systems. The common mode current is not just the result of the fast transitions of IGBTs, but also of the system configuration, which produces common mode voltages. This work aims to study alternatives that minimize, naturally, those voltages through its configuration, reducing the need for additional components, such as passive filters or active circuits. It is pointed, that the first step consisted in the understanding of the problem of the common mode voltage generation. In order to address this objective, an inverter composed of two bridges, switching in opposition, called double-three-phase was designed. Its potential for noise mitigation, as well, its implementation, with two identical inverters was evaluated by simulations. The prototype was tested against a third module of the same type, under the same conditions. The comparison of the results indicated that the proposed configuration can be efficient in the common mode noise control, with 86% reduction. The behavior observed through the prototype allows a better understanding of the phenomena involving common mode current. Thus, in the light of the research, we note that, conceptually, the proposed solution stands out for its practicality and simplicity, from the others presented in the literature.

De l’avion plus électrique, en passant par l’hybridation de véhicules automobiles et jusqu’aux implants cardiaques d’assistance circulatoire, la compacité est devenue le graal de l’électrotechnique embarquée moderne. En effet, la densité de puissance des systèmes électromécaniques ne cesse de s’accroitre. Ainsi, pour répondre aux besoins de forte intégration, les convertisseurs en électronique de puissance trouvent un vecteur de développement dans l’augmentation de leur température et des fréquences de fonctionnement mais aussi dans la réduction des temps de commutation des interrupteurs, leur permettant de réduire leurs pertes thermiques et ainsi, de réduire leurs besoins en refroidissement. Les moteurs et générateurs électriques évoluent avec des topologies aussi diverses qu’innovantes pour répondre aux besoins d’intégration, robustesse et sureté de fonctionnement. Particulièrement, les bobinages des moteurs sont les premiers éléments sur le front de bataille. Au sein du bobinage s’effectuent les échanges entre moteur et convertisseur. L’augmentation des contraintes fréquentielles et transitoires sous forme de fronts de courant et tension issus des ensembles d’électronique de puissance constituent des défis en termes de compatibilité électromagnétique (CEM) pour les systèmes embarqués. Le travail présenté ici est le fruit d’une étroite collaboration entre la société NOVATEM et le laboratoire Génie de Production de l’ENIT de Tarbes au travers d’un financement CIFRE, en association avec la plateforme Labceem de l’IUT de Tarbes. Il propose d’apporter des modèles prédictifs permettant de déterminer les conséquences de ces contraintes d’intégration dans les systèmes mécatroniques de puissance dès les premières étapes de leur conception. Les perturbations conduites dont la source HF est au sein des interrupteurs de puissance du convertisseur, sont façonnées par les impédances caractérisant le chemin de couplage dont le moteur fait partie intégrante. Ce travail vise à élaborer des méthodes et outils pour contribuer à l’étude prédictive de la compatibilité électromagnétique (CEM) des ensembles mécatroniques en essayant de couvrir une plage de fréquence allant de 0 à 300 MHz. Dans une première partie, un état de l’art est détaillé afin de délimiter le contexte et les frontières de l’étude. Puis, un deuxième chapitre porte sur la modélisation analytique de bobinages concentrés de moteurs électriques. Les modèles analytiques établis permettent de déterminer les paramètres de réseaux de circuits pour effectuer des simulations dans le domaine temporel et harmonique. Contrairement aux modèles comportementaux de moteurs répandus dans la littérature, les modèles ici synthétisés prennent en compte les paramètres physiques des bobinages. Ils donnent la possibilité à l’utilisateur de paramétrer les architectures de bobinages concentrés en changeant des paramètres tels que la géométrie des bobines, les matériaux d’isolation ou encore la perméabilité des culasses. Un troisième chapitre, détaille l’établissement d’une méthode rationnelle d’extraction numérique de paramètres fonctionnels et parasites des PCB multicouches de puissance. Cette méthode, de par la prise en compte de paramètres physiques, s’inscrit dans une logique générique et prédictive. Finalement, dans le dernier chapitre, les outils et méthodes précédemment établis sont appliqués à l’étude d’un système réel de motorisation de véhicule électrique développé par la société partenaire Novatem. Le caractère physique et prédictif de ces outils vise à permettre l’expérimentation virtuelle sur l’ensemble moteur-convertisseur sans la nécessité de prototypes. Ce dernier chapitre illustre l’intérêt d’une approche physique en modélisation pour la compatibilité électromagnétique de systèmes mécatroniques. / From the more electrically operated aircraft, to the hybridization of motor vehicles, all the way to electromechanic cardiac implants, compactness has become the holy grail of modern embedded electrical engineering. Indeed, the power-to-weight ratio demands for electromechanical systems has greatly increased. To meet these high integration needs, power electronic converters find a vector of development by increasing their temperature and operating frequencies but also by reducing the switching time of power switches, thus enabling them to reduce their power losses and thereby reducing their cooling requirements. Electric motors and generators operate with various innovative topologies that meet integration, robustness and reliability needs. Motor windings, particularly, are the first motor components on the battle front. It is at the heart of the winding that occur the exchanges between motor and converter. In terms of electromagnetic compatibility (EMC) for embedded systems, the increased frequency and transient stresses in the form of current and voltage edges from the power electronic assemblies are considered steep challenges. The work presented herein is the result of a close cooperation between the company Novatem and the laboratory Génie de Production of ENIT de Tarbes, through CIFRE funding, in combination with the Labceem platform of IUT of Tarbes. Its aim is to develop predictive models that will serve to determine the consequences of such integration constraints in power mechatronic systems that are in the early stages of design. Conducted disturbances whose HF source is located at the inverter power switches are shaped by the impedances characterizing the coupling path of which the electrical machine is an integral part. This work proposes to develop methods and tools to support the predictive study of electromagnetic compatibility (EMC) of mechatronic assemblies, by attempting to cover a modeling frequency range that goes from 0 to 300 MHz’s. In the first chapter of this work, a literature review is detailed for the definition of the context and boundaries of the study. A second chapter focuses on the analytical modeling of concentrated windings in electric motors. The analytical models that are established allow determination of circuit networks settings to perform time- and frequency- domain simulations. Unlike the widespread behavioral models of electrical machine in the literature, the models that are synthesized here take into account the physical parameters of the coils. The user of such models is offered the opportunity to account for the different winding architectures, by changing core parameters such as geometry, insulation materials or permeability. A third chapter describes the establishment of a rational method for extraction of functional and parasitic parameters in multilayer Power PCBs. This method being of a generic and predictive logic aims to account for physical parameters. Finally, in the last chapter, the previously established tools and methods are applied to the study of a real electric vehicle drive system developed by the company Novatem. The physical and predictive value of these tools allows for execution of virtual experimentations on the motorconverter assembly without the need for prototypes. This chapter illustrates the value of a physical approach to modeling the electromagnetic compatibility of mechatronic systems.

Nos últimos 20 anos, o inversor de frequência PWM passou a ser largamente utilizado. Dentre as razões principais de sua ampla difusão, cita-se a introdução do IGBT que, devido à sua capacidade de comutação rápida, possibilitou a redução de perdas, tamanho e custo dos conversores, ao mesmo tempo em que permitiu o uso do motor de indução em aplicações que demandam alto desempenho dinâmico. Porém, esta mesma característica que trouxe tais benefícios, contribuiu para acentuar os efeitos relacionados a fenômenos eletromagnéticos, devido à rápida transição que produz sinais em alta frequência, responsáveis por tornar os sistemas de acionamentos potenciais fontes de interferência eletromagnética. Os principais fenômenos desta natureza são a tensão de onda refletida, associada a ruídos de modo diferencial, e a corrente de modo comum. De maneira geral, a corrente de modo comum tem maior potencial de contribuição para a emissão radiada que a de modo diferencial e, em sistemas de acionamento, constitui a principal fonte de interferência eletromagnética. Esta não é resultado apenas da rápida comutação dos IGBTs, mas, também, da configuração do sistema, que propicia o surgimento das tensões de modo comum. Este trabalho visa estudar alternativas que minimizem, naturalmente, estas tensões através de sua configuração, reduzindo-se a necessidade de novos componentes, como filtros passivos ou circuitos ativos. Ressalta-se, assim, que o primeiro passo consistiu-se na compreensão do problema de geração da tensão de modo comum. Visando atingir os propósitos anteriormente mencionados, foi idealizado um inversor, composto de duas pontes chaveando em oposição, chamado de duplo-trifásico. A partir de simulações, avaliou-se seu potencial e definiu-se sua implementação, a partir de dois inversores idênticos. Testou-se o protótipo contra um terceiro módulo de mesmo tipo, em iguais condições. A comparação dos resultados indicou que a configuração proposta pode ser eficiente no controle do ruído de modo comum, obtendo-se valores de redução de 86%. Nota-se que o comportamento observado via o protótipo, permite um melhor entendimento dos fenômenos relativos à circulação da corrente de modo comum. Desta forma, à luz da pesquisa realizada, nota-se que, conceitualmente, a solução proposta se destaca das demais apresentadas na literatura pela sua exequibilidade e simplicidade. / Over the last 20 years, the PWM frequency inverter has become widely used. Among the main reasons for its widespread distribution is the introduction of the IGBT, due to its ability for fast switching allowing the reduction of losses, size and cost of the converters, and the use of the induction motor in applications that demand high dynamic performance. However, this same characteristic that brought such benefits, stressed the effects related to electromagnetic phenomena, due to the fast transition that produces high frequency signals, responsible for turning drive systems, potential sources of electromagnetic interference. The main phenomena of this nature are the reflected wave overvoltage, associated with differential mode noise, and the common mode current. In general, the common mode current has greater potential of contribution to the emission of radiated interference than the differential mode current and is the main source of electromagnetic interference in drive systems. The common mode current is not just the result of the fast transitions of IGBTs, but also of the system configuration, which produces common mode voltages. This work aims to study alternatives that minimize, naturally, those voltages through its configuration, reducing the need for additional components, such as passive filters or active circuits. It is pointed, that the first step consisted in the understanding of the problem of the common mode voltage generation. In order to address this objective, an inverter composed of two bridges, switching in opposition, called double-three-phase was designed. Its potential for noise mitigation, as well, its implementation, with two identical inverters was evaluated by simulations. The prototype was tested against a third module of the same type, under the same conditions. The comparison of the results indicated that the proposed configuration can be efficient in the common mode noise control, with 86% reduction. The behavior observed through the prototype allows a better understanding of the phenomena involving common mode current. Thus, in the light of the research, we note that, conceptually, the proposed solution stands out for its practicality and simplicity, from the others presented in the literature.

Police officers continue to sustain injuries during close proximity encounters with non-compliant and combative suspects. The purpose of this quasi-experimental study was to examine whether the use of less-lethal instruments, such as conducted energy devices, oleoresin capsicum, impact batons, and hands/feet defensive tactic reduced police officer injury during confrontations with uncooperative suspects at a medium-sized police department in a southern state. Fichtelberg's democratic policing was used as the theoretical framework for this study. Data were acquired from Suspect Resistant Reports (n = 409) written by police officers over a 10-year period (1/05 - 12/14). The dependent variable was police officer injury and the categorically ranked independent variable was the less-lethal instrument. A significant association was found between officer injuries and less-lethal instruments using chi-square analysis (p

Depuis de nombreuses années, la prise en compte des critères de compatibilité électromagnétique (CEM) constitue une étape capitale dans la conception des systèmes électroniques. Or, l'augmentation de la complexité des circuits intégrés rend indispensable l'étude du comportement électromagnétique directement au niveau du silicium. L'objectif de ces travaux est la définition d'une méthodologie de prédiction, avant fonderie, de l'émission conduite des circuits intégrés. Celle-ci s'appuie sur le langage VHDL-AMS et le modèle ICEM (Integrated Circuit Electromagnetic Model), et peut s'intégrer dans un flot de conception industriel. / For many years, taking into account electromagnetic compatibility (EMC) constraints has been a fundamental requirement in electronic system design. However, the increase in complexity of integrated circuits now demands the study of their electromagnetic behavior at chip level. The objective of this work is the definition of a methodology aimed at predicting conducted emission in integrated circuits. This methodology is based on the VHDL-AMS language and the ICEM (Integrated Circuit Electromagnetic Model) model, and can be integrated into an industrial design flow.

Aujourd'hui CEM normative sur RSIL ne permet pas de garantir le bon fonctionnement de façon systématique. La sûreté est assurée au moyen de marges CEM, souvent excessives. Le système est donc sous optimal Par ailleurs, le fonctionnement des convertisseurs sur RSIL n'est pas forcément représentatif du fonctionnement réel: le RSIL n'est pas forcément représentatif des impédances des réseaux embarqués. De ce fait, le filtrage d'un convertisseur peut être optimisé sur RSIL mais n'est plus forcément optimal dès qu'on est sur un réseau réel. L'objectif de cette thèse est de progresser dans la modélisation CEM des réseaux embarqués, en vue de pouvoir prédire le comportement, et d'optimiser les moyens de filtrage. / Today normative LISN EMC does not guarantee the proper functioning systematically. Safety is ensured by EMC margins often excessive. The system is therefore suboptimal Furthermore, the operation of the converters on the AN is not necessarily representative of the actual operation : the AN is not necessarily representative of the impedances of embedded networks . Thus , filtering of a converter can be optimized but on the AN is not necessarily optimal since it is a real network . The objective of this thesis is to advance the EMC modeling of embedded systems in order to predict behavior, and optimize the filter means.

Five chapters of this dissertation concentrate on the characterization and cancellation of high frequency parasitic parameters in EMI filters. One chapter addresses the interaction between the power interconnects and the parasitic parameters in EMI filters. The last chapter addresses the characterization, evaluation and design of noise separators. Both theoretical and experimental analyses are applied to each topic. This dissertation tries to explore several important issues related to EMI filters and noise separators. The author wishes to find some helpful approaches to benefit the understanding and design of EMI filters. The contributions of the dissertation can be summarized below: 1) Identification of mutual couplings and their effects on EMI filter performance 2) Extraction of mutual couplings using scattering parameters 3) Cancellation of mutual couplings to improve EMI filter performance 4) Cancellation of equivalent series inductance to improve capacitor performance 5) Analysis of mode transformations due to the imperfectly balanced parameters in EMI filters 6) Analysis of interaction between power interconnects and EMI filters on filter high-frequency performance 7) Modeling and design of high-performance noise separator for EMI diagnosis 8) Identification of the effects of parasitics in boost PFC inductor on DM noise Although all topics are supported by both theory and experiments, there may still be some mistakes in the dissertation. The author welcomes any advice and comments. Please send them via email to shuowang@ieee.org. Thanks / Ph. D.

With the development of power electronics, electromagnetic interference (EMI) and electromagnetic compatibility (EMC) issues have become more and more important for both power converter designers and customers. This dissertation studies EMI noise emission characterization and modeling in power converters. A modular-terminal-behavioral (MTB) equivalent EMI noise source modeling approach is proposed. This work is the first to systematically develop a 3-terminal EMI noise source model for a switching phase-leg device module. Each module is modeled as pairs of equivalent noise current sources and source impedances. Although the proposed MTB modeling approach applies the linear circuit theory to a semiconductor switching device, which exhibits nonlinear behavior during switching transients, the analysis and experiments show that the nonlinearity has negligible practical effect on the modeling methodology. The validation range of the modeling methodology has been analyzed. One of the differences between the proposed MTB model and the other state-of-the-art models is that the MTB model characterizes and predicts the CM and DM noise simultaneously. The inseparable high-frequency CM and DM noise characteristics contributed by the source impedance and propagation path are analyzed. A comprehensive evaluation of different EMI noise source modeling approaches according to the criteria of accuracy, feasibility and generality has been presented. Results show that the MTB modeling approach is more accurate, feasible and general than other approaches. The modular and terminal characteristics of the MTB noise source model are verified in two more complicated cases. One example is the application of the MTB equivalent source model in a half-bridge AC converter with variable switching conditions. Although the MTB model is derived under a certain operating condition, the models under different conditions can be combined together to predict the EMI noise for the converter with variable switching conditions. Another example is the application of the MTB equivalent source model in multi-phase-leg converters. The EMI noise of a full-bridge converter is predicted based on the MTB equivalent source model of one phase-leg module. The implementation procedures and results for both applications are verified by the experiment. The applicability of the MTB model in different type of converters is discussed. Based on the MTB model, EMI noise management is explored. The parametric study based on the MTB model is demonstrated by selecting DC-link decoupling capacitors for voltage source converter (VSC). The EMI effect of a decoupling capacitor for a device s safe operation is analyzed, and this analysis shows the terminal characteristics of the MTB model. Both the EMI and voltage overshoot are predicted by the MTB model. A completed converter-level EMI model can be derived based on the noise source model and propagation path model. This model makes it possible to optimize the EMI filter design and study the EMI noise interactions between converters in a power conversion system. / Ph. D.

The purpose of this study is to contribute knowledge about how a few pedagogues apprehend playing’s opportunities to create social relationships between children. The purpose is also to contribute knowledge about how a few pedagogues apprehend their role in children’s relationship work in playing. To obtain empirical material to our study we have completed qualitative interviews with eight pedagogues who work in extended school in four different schools. The theoretical framework we have used to analyze the empirical data is symbolic interactionism, in particular concepts from Erving Goffman’s The Presentation of Self in Everyday Life (1959). According to the pedagogues, playing create social relationships between children by their fantasy, creativity and by their own initiative. According to the pedagogues, playing clarifies children how to work together and how to behave towards other children. To include and prevent children from being excluded the pedagogues use different tools to support them in entering social relationships with other children. The pedagogues use free play to get children to learn how to take responsibility and in an independently way create new social relationships with other children. The pedagogues use adult- conducted play to get children to interact in play, to enter community and create social relationships. The pedagogues feel they are in children´s free play depending on how the children act for example if there is a problem regarding children´s language or behavior in playing. In adult-conducted play the pedagogues apprehend their role to be an explicit and determined leader and be the one who always controls children’s play. The pedagogues also apprehend their role in adult-conducted play to break up subgroups and lead the children away from evil playing. / Syftet med studien är att bidra med kunskap om hur ett antal pedagoger uppfattar lekens möjligheter för barn att skapa sociala relationer. Syftet är även att bidra med kunskap om hur ett antal pedagoger uppfattar sin roll i barns relationsarbete i leken. För att samla in empiriskt material till vår studie har vi genomfört kvalitativa intervjuer med åtta pedagoger som arbetar på fritidshem på fyra olika skolor. För att analysera det empiriska materialet använder vi oss av symbolisk interaktionism i form av ett antal begrepp från Erving Goffmans Jaget och maskerna: En studie i vardagslivets dramatik (1959). Pedagogerna uppfattar att leken skapar sociala relationer mellan barnen via deras fantasi, kreativitet, egna initiativ. Pedagogerna uppfattar att i leken får barnen lära sig att samarbeta och hur man ske bete sig mot andra barn. För att inkludera och motverka att barn är exkluderade uppfattar pedagogerna att de använder sig av olika verktyg för att stötta dem att ingå i sociala relationer med andra barn. Pedagogerna uppfattar att fri lek används för att barnen ska lära sig att ta ansvar och på ett självständigt sätt skapa nya sociala relationer med andra barn. Pedagogerna uppfattar att de använder styrd lek för att barnen ska få interagera i lek, ingå i gemenskap och skapa sociala relationer. Pedagogerna uppfattar att de intar olika roller i barnens fria lek beroende på hur barnen agerar i leken. Bland annat om det är problem angående barnens språkbruk eller beteende i leken. I den styrda leken uppfattar pedagogerna att sin roll är att vara en tydlig och bestämd ledare och hela tiden vara den som styr barnens lek. Pedagogerna uppfattar även att sin roll i den styrda leken är att bryta upp subgrupper och leda barnen bort från ondskefulla lekar.

In a short time touchscreens has become one of the most used methods for input to smartphones and other machines such as cash registers, card terminals and ATMs. While the technology change was quick it introduces the possibility of new security holes. Compromising emanations is a possible security hole in almost all electronic equipment. These emanations can be used in a side-channel attack if they leak information that compromise the security of the device. This thesis studies a single-board computer (SBC) with a touchscreen and a smartphone in order to evaluate if any usable information leaks regarding what is done on the touchscreen i.e. where on the screen a user touches. It is shown that the location of a touch can be read out from information leaking through the power cable and wirelessly from the single-board computer. It is also shown that basic information can be read out wirelessly from the smartphone but further testing is required to evaluate the possibility to extract usable information from the device.