Dissertations / Theses on the topic 'EMI/EMC'

This report presents a theoretical background to electromagnetic interference from photovoltaic systems that use power optimizers. The purpose is to carry out measurements at an existing facility to analyze and discuss appropriate measures to minimize disturbance levels. The work is designed by Glava Energy Center (GEC) and measurements are carried out together with the Swedish Electrical Safety Agency (Elsäkerhetsverket) and Rencke's El & Mätteknik. The report concludes with the results of measurement and a discussion of appropriate measures to achieve electromagnetic compatibility (EMC), designed for the specific facility. Finally, a brief discussion is given about future work in this area.

Electromagnetic compatibility and compliance with relevant standards is imperative for commercial success for any type of electronic equipment. Since more and more electronics are constantly added into today’s vehicles, this is a highly significant matter in the automotive business. The primary source of electric energy in an on-road vehicle is typically a 12 or 24 volt battery; this makes voltage step down converters ubiquitous in virtually any automotive electronic system. In strive for ever more environmental friendly and energy efficient solutions a switch mode power supply is most often the given choice when it comes to the task of voltage conversion. However, the use of switch mode power supplies presents a new set of challenges when it comes to successfully comply with the electromagnetic emission standards. Knowledge and understanding about how different design parameters impact on EMC performance is key when few prototype runs and short time to market lies in focus. This text will investigate just how different layout design parameters affect the radiated emissions from a buck converter. Emphasis lies on radiated emissions in the lower frequency range up to a few MHz. Both computer simulations and practical measurements indicate the same thing; in the lower part of the frequency spectrum, when measured according to CISPR 25, radiated emissions from buck converters are dominated by voltage driven mechanisms. Along the way we will see how PCB layout alone can be responsible for differences in measured radiated emission levels of well over 20 dB.

International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California
The UMR Solar Car uses a telemetry processor to collect, compute, and transmit data to the driver of the car and a nearby chase vehicle. The original processor had deteriorated from environmental extremes and vibration. There were also problems with electromagnetic interference from the high efficiency electric motor switching electronics, difficulties with the many unplanned additions made to the processor in the field, and the unstructured software that was becoming difficult to maintain. This project consists of creating a replacement telemetry system that is more robust mechanically, and electrically, substantially improving the EMI performance of the device, and reworking the hardware and software to make it easier to maintain and upgrade.

Les convertisseurs de puissance sont largement utilisés de nos jours dans des applications qui demandent une grande autonomie énergétique, comme par exemple ceux qui sont alimentés par des batteries. En particulier, les amplificateurs de type Class-D sont fréquemment utilisés dans les applications audio. Ces amplificateurs commutés ont une architecture ressemblante à celle d'un convertisseur DC-DC, ce qui les permet d'avoir une efficacité énergétique élevée. Cependant, leur inconvénient majeur est la forte émission en perturbations électromagnétiques (EM). Cela peut causer des problèmes de conformité avec les normes de compatibilité électromagnétique (CEM), ou bien perturbé le bon fonctionnement des applications électroniques qui l'entour. Pour cela, ils existent de nombreuses études qui permettent de réduire les émissions d'un amplificateur de Class D. Cependant, cela n'est pas suffisant pour retirer le filtre de CEM. Il est donc nécessaire d'optimiser ces filtres et de faciliter leurs conceptions. Ceci est le but de la présente thèse et il est divisé en quatre grandes parties. La première partie commence par développer une technique de modélisation dans le domaine fréquentiel. Cette technique qui est basée sur la détermination et la manipulation des matrices d'impédances a comme but de simuler et prédire les perturbations EM générées par un amplificateur de Class D. Tous les aspects théoriques de la méthode ont été développés. Ensuite, une application pratique sur un système de Class D dédié à la téléphonie mobile nous a permis de valider la méthode jusqu'à une fréquence de 100 MHz. Un amplificateur de Class D est une source de perturbation aussi bien sur les rails d'alimentation que sur les rails de sortie. Pour cela, le filtre de CEM est nécessaire sur les rails de l'alimentation comme il y est en sortie. Néanmoins, un filtre correctement construit doit être conçu en prenant en compte l'impédance de la charge qui est la batterie dans ce cas. Pour cela, la deuxième partie a pour objectif la mesure de l'impédance de la batterie sur la gamme de fréquence considérée. Ainsi, une technique de mesure d'impédance de batterie en utilisant un impédance mètre est développée. Ensuite, une application expérimentale sur un convertisseur DC-DC et une batterie nous a permis de valider la procédure de mesure. La troisième partie s'est focalisée sur l'optimisation du filtre de CEM. Le modèle fréquentiel développé dans la première partie est intégré dans une boucle d'optimisation basée sur un algorithme génétique. L'optimisation inclus plusieurs critères dans sa fonction objective qui sont l'augmentation de la capacité du filtre à réduire les émissions EM, la diminution des pertes supplémentaires due à l'utilisation du filtre et finalement le gain du filtre dans la bande de fréquence du signal audio. Cette étude est poursuivie par une validation expérimentale. La quatrième et la dernière partie étudie et quantifie les impacts du filtre de CEM sur la qualité audio de l'amplificateur. En effet, le filtre de CEM est l'un des chemins propagation du signal audio. Par suite, tout comportement non linéaire du filtre conduit à la distorsion du signal audio. Pour cela, cette partie est dédiée à la modélisation et la simulation des composants passifs contenant un matériau magnétique. En particulier, l'étude s'est focalisée sur la modélisation des perles de ferrite en utilisant le modèle de matériaux magnétiques Jiles-Aterthon. Les résultats de simulations sont comparés avec la mesure dans le domaine temporel et fréquentiel. En plus, le calcul du taux de distorsion harmonique nous a permis de valider le modèle sur une large plage d'amplitude
Switching power management circuits are widely used in battery powered embedded applications in order to increase their autonomy. In particular, for audio applications, Class-D amplifiers are a widespread industrial solution. These, have a similar architecture of a buck converter but having the audio signal as reference. The switching nature of these devices allows us to increase significantly the power efficiency compared to linear audio amplifiers without reducing the audio quality. However, because of the switching behavior, Class-D amplifiers have high levels of electromagnetic (EM) emissions which can disturb the surrounding electronics or might not comply with electromagnetic compatibility (EMC) standards. To overcome this problem much architecture appeared in the state of the art that reduces the emissions, however, this has never been enough to remove electromagnetic interference (EMI) filters. It is then useful to optimize these filters, thus, it has been set as the goal of this PhD thesis. The latter has been divided to four main axes which can be resumed by the following. First, this work started by developing a frequency domain modeling method in order to simulate and predict the EMI of Class-D amplifiers in the final application. The method is based on system to block decomposition and impedance matrix modeling and manipulation. After providing all the theoretical background, the method has been validated on integrated differential Class-D amplifier. The experimental measurements have permitted to validate the method only up to 100MHz. However, this is sufficient to cover the conducted EMC frequency band. Second, the EMI at the supply rails of Class-D amplifiers has been treated. As the battery is often the same power supply for all applications in an embedded system, an EMI filter or a decoupling capacitor is needed to prevent the noise coupling by common impedance. Designing this filter needs the knowledge of the battery impedance at the desired frequencies. Therefore the present work dealt also with measuring the high frequency impedance of a battery. Afterwards, an experimental validation has been carried on with a DC-DC converter and a Class-D amplifier. The developed model allows a virtual test of the switching device in the final application. However, it is more useful if the model is able to help the system integrator in designing filters. Thus, third, the model has been implemented in an optimization loop based on a genetic algorithm in order to optimize the filter response, and also, reduce the additional power losses introduced by an EMI filter. The optimization search space has been limited to the components available on the market and the optimization result is given as component references of the optimal filter referring to the optimal solution found. This procedure has been validated experimentally. Finally, EMI filters often are constituted by magnetic components such as ferrite beads or inductors with magnetic cores. Thus, introducing the EMI filter in the audio path, adds a nonlinear behavior in the audio frequency band. Designing a high quality EMI filter require taking into account this phenomenon and studying its impact of the original amplifier audio performance. Therefore, the Jiles-Atherton model for magnetic materials has been used for ferrite bead modeling. Hereafter, the impact on the time and frequency domain signals has been simulated and compared to measurements. Finally, the total harmonic distortion (THD) has been computed for different signal amplitudes and compared to the THD measured using an audio analyzer. Accurate results have been obtained on a wide range of signal amplitudes. As a conclusion, this work aimed to design optimal EMI filters for Class-D amplifiers. Thus, we dealt with improving their EMI response, reducing their additional power losses and evaluating their impact on the audio quality

Measurement-based behavioral electromagnetic interference (EMI) models have been shown earlier to accurately capture the EMI behavior of switched power converters. These models are compact, linear, and run in frequency domain, enabling faster and more stable simulations compared to the detailed lumped circuit models. So far, the behavioral EMI modeling techniques are developed and applied to the converter's input side only. The resulting models are therefore referred to as "terminated EMI models". Under the condition that the output side of the converter remains fixed, these models can predict the input side EMI for any change in the impedance of the input side network. However, any change at the output side would require re-extraction of the behavioral model. Thus the terminated EMI models are incapable of predicting the change in the input side EMI due to changes at the output side of the converter or vice versa. The above mentioned limitation has been overcome by an "un-terminated EMI model" proposed in this dissertation. Un-terminated EMI models are developed here to predict both the common-mode (CM) and the differential (DM) noise currents at the input and the output sides of a motor-drive system. The modeling procedure itself has been simplified and now requires fewer measurements and results in less noise in the identified model parameters. Both CM and DM models are then combined to predict the total noise in the motor drive system. All models are validated by experiments and their limitations identified. A significant portion of this dissertation is then devoted to the application of behavioral EMI models in the design of EMI filters. Comprehensive design procedures are developed for both DM and CM filters in a motor-drive system. The filters designed using the proposed methods are experimentally shown to satisfy the DO-160 conducted emissions standards. The dissertation ends with a summary of contributions, limitations, and some future research directions.
Ph. D.

This dissertation discusses immunity measurement and improvement of intelligent components in the automotive field. The wide frequency band and the failure criterion to represent the behavior of components under pressure of interference are the difficulties in the immunity measurement. The other main task in this dissertation is to improve the immunity of components without adding too much cost. The dissertation is divided into three chapters. The first chapter concentrates on immunity measurement. The injection circuit is important to the in situ test bench because it limits the measurement bandwidth and the accuracy of the measurement. An on board on board bias tee extends the measurement bandwidth from 15 kHz to 1 GHz. A measurement algorithm, that avoids the non-uniform comparison between the sampling data and the reference signal, improves the accuracy of the immunity result. Two failure ceriteria can identify the linear and nonlinear distortion of an analogue digital converter (ADC). The second chapter presents interference signal detection and compensation technique. A simple technique is used to detect the continuous wave interference (CWI) on the power supply and at the analogue input port of the microcontroller without adding too many components. The simulation of the schematic circuit and the measurement can validate the effectiveness of the method. Finally, based on the detection result; a compensation technique compensates both the interference signal on the power supply and at the input port of the microcontroller. The third chapter is composed of three sections. The first section introduces the defensive software and hardware methods to protect the microcontroller. Then the second section presents the application of the interference detection technique to improve the immunity of components in the automotive field. Finally the third section shows the influence of interference signal on a proportional integral derivative (PID) control system; the proportional integral derivative control system is modelled in Matlab. The interference detection is used in the fault tolerant control field to avoid the false fault detection.

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O setor automotivo nacional, no segmento de fabricação de carrocerias para ônibus, vem buscando melhorar a qualidade de produção de seus veículos, visando atender as exigências do mercado interno e externo, por meio de especificações de projetos eletrônicos seguindo normas internacionais. Neste contexto, as normas de compatibilidade eletromagnética destacam-se, pois, possuem um papel importante para garantir que os equipamentos possam operar de forma segura, sem gerar ou sofrer interferências. Este trabalho tem como objetivo desenvolver uma metodologia para projetar produtos eletrônicos que necessitam atender normas de compatibilidade eletromagnética, por meio de estudos de técnicas de emissões radiadas e conduzidas, e uso de ferramentas computacionais para simulação da placa de circuito impresso. A partir deste estudo, pode-se diminuir investimentos com laboratórios de testes, tempo de desenvolvimento e disponibilizar produtos ao mercado de forma mais eficiente. O uso de técnicas apropriadas e boas práticas em projetos são meios adequados para atender requisitos de normas, porém a evolução das tecnologias e adição de mais circuitos em áreas menores torna necessário avançar nos conhecimentos. Assim, deve-se compreender de forma detalhada as técnicas para emissões de modo comum e diferencial, desenvolver simulações que possam prever resultados em testes de laboratórios e propor alterações em projeto mecânico ou eletrônico que atendam os limites determinados em normas.
The national automotive division, more precisely in the bus manufacturing segment, efforts are being deposited to improve the manufacturing quality of its vehicles in order to meet the requirements of the internal and external market through electronic projects based on international standards. Furthermore, the electromagnetic compatibility standards stand out because they have a major importance ensuring that electronic devices are able to provide safety to its users, without interfering or being interfered by other devices. The objective of this research is to develop a methodology to design electronic devices which must meet the standards requirements of electromagnetic compatibility. This goal is achieved through the study of radiated and conducted emissions techniques, and using computational tools for simulation of printed circuit boards. From this study it will be possible to reduce costs with laboratory tests, reduce the time required for development, and provide products to the customers in an efficient way. The use of appropriated techniques and good practices during the designs process are the proper way to meet standards and requirements. However, with the evolution of technology and addition of more electronic circuits in smaller areas requires to acquire more knowledge and go deeper in this study. Thus, it is necessary to understand in details the common mode and differential emissions technics, develop simulations which can provide a preview of what the laboratory tests may result, and propose changes in the mechanic and electronic project design in order to meet the limits of the requirements determined in the standards.

DE LA TESIS

Esta Tesis se centra en el estudio de las perturbaciones conducidas generadas por un ondulador de tensión en configuración de puente y alimentado de red a través de un rectificador no controlado. El objetivo de esta Tesis es poder identificar el origen de las perturbaciones y poder cuantificar de una forma relativamente rápida y sencilla el efecto de diversos factores (topología, lay-out, técnicas de modulación y tipo de componentes) sobre la propagación de las mismas. Para ello se ha desarrollado una metodología de estudio que es perfectamente válida y aplicable sin grandes dificultades a otro tipo de topologías, utilicen o no la conmutación dura. El método de estudio se basa en la estructura fuente-medio de propagación-perturbación y en el planteamiento de circuitos equivalentes de parámetros concentrados, cuyas ecuaciones son resueltas en el dominio frecuencial. En esta metodología, que permite discriminar la contribución de los dos modos de propagación (modo común, MC, y modo diferencial, MD) al nivel global de perturbación, se ha primado la sencillez y robustez de simulación del modelo frente a la exactitud. El método propuesto ofrece buenos resultados hasta una frecuencia de 5MHz aproximadamente.

En el Capítulo 1 se introduce el problema planteado por las perturbaciones electromagnéticas generadas por los convertidores conmutados, se describe y caracteriza todo el instrumental (analizador de espectros, red artificial, pinza amperimetrica de alta frecuencia), la planta experimental así como la herramienta matemática utilizada.

En el Capítulo 2 se aborda el tema de la caracterización del medio de propagación de las perturbaciones. En primer lugar se describe el método de medida de impedancias utilizado, que es una de las aportaciones de la Tesis, para después presentar los resultados obtenidos a la hora de caracterizar las impedancias significativas del sistema. A partir de estas medidas se obtienen circuitos equivalentes de parámetros concentrados que caracterizan el medio de propagación.

En el Capítulo 3 se estudian las perturbaciones que generan individualmente el rectificador de entrada y el ondulador. El estudio se lleva a cabo sobre una configuración monofásica para una mayor simplicidad del mismo. En este Capítulo se caracteriza la fuente de perturbación en el caso de ambos convertidores y, junto con la caracterización del camino de propagación obtenida en el Capítulo 2, se calculan las perturbaciones generadas. Gracias a los modelos obtenidos es posible calcular el efecto de diversos parámetros sobre las perturbaciones y la contribución de ambos modos de propagación (modo común y diferencial) al nivel final de perturbación.

En el Capítulo 4 se combinan los resultados obtenidos en el Capítulo 3 para obtener la perturbación que se propaga hacia la red en la asociación en cascada de ambos convertidores. Tanto en el Capítulo 3 como en el Capítulo 4 la validación del modelo se lleva a cabo por comparación de los resultados experimentales con los obtenidos por simulación.

Una vez cumplidos los objetivos de la Tesis, el Capítulo 5 ilustra la validez de la metodología desarrollada en el Capítulo 3. En el Capítulo 5 se aplica esta metodología al estudio de las perturbaciones en MC generadas por el ondulador y que se propagan hacia la carga. Este Capítulo es una extensión al caso trifásico y un ejemplo de aplicación de gran interés industrial. En este Capítulo aparece una de las aportaciones de la Tesis: una técnica de modulación orientada a la reducción del MC generado por el ondulador. Para demostrar la validez del modelo se comparan las medidas de corriente en MC en el lado carga con los valores obtenidos a partir del modelo.

Las conclusiones de la Tesis aparecen en el Capítulo 6. También se describen los trabajos futuros que se sugieren a partir de los resultados de la Tesis.
OF THE THESIS

The subject of this Thesis is to study conducted disturbances produced by a voltage source inverter supplied from the mains through a rectifier. The main goal is to identify the origin of conducted disturbances and also quantify in a quick and easy way the influence of different factors (topology and lay-out of the converter, switching patterns, components) on EMI . In order to achieve this goal, a systematic analysis approach has been developed. This new methodology can be easily applied to any converter topology, whatever the kind of switching (soft or hard) is used. The analysis is based on the source of noise-propagation path-disturbance approach and consists in the setting out of two equivalent circuits of lumped parameters, one for each mode of propagation. This separate treatment of both modes of propagation allows the calculation of their contribution to the global level of disturbance. Equations drawn from these equivalent circuits are solved in the frequency domain. This approach avoids all the problems of time-domain simulations and provides robust and quick simulations rather than very accurate results. The simulation results of this methodology show a good agreement with experimental measures up to 5MHz.

Chapter 1 describes problems caused by electromagnetic disturbances generated by switched power converters. The state of the art about this matter is presented. All instruments used to carry out measures (spectrum analyser, LISN, HF current clamp) are described and modelled. The experimental set-up is thoroughly described. Also some considerations about mathematical tools used are presented.

Chapter 2 is devoted to study the propagation path of disturbances. First of all, the impedance measuring method is described, which is one of the contributions of the Thesis. After that, main impedances of the system are identified and measured. From these results, equivalent circuits of lumped parameters that model the main impedances of the propagation path are derived.

In Chapter 3, disturbances generated in a single phase arrangement by the rectifier and the inverter working separately are studied. Source of noise in both cases are identified and modelled. Finally, disturbances are calculated taking into account results of Chapter 2.

Results obtained in Chapter 3 are combined in Chapter 4 in order to obtain the disturbance reaching the mains when both converters (rectifier and inverter) are connected in cascade. Experimental validation of the model are presented in Chapters 3 and 4, by comparing results of measures with those provided by simulation.

Once main goals of the Thesis are achieved, Chapter 5 shows the validity of the methodology developed in Chapter 3 when it is used to calculate the CM currents in the load side of a three-phase inverter. In this Chapter another contribution of the Thesis is presented: a new modulation technique for three-phase inverters specially intended to reduce CM currents in the load side. Comparison between simulation results and measurements show a good agreement.

The conclusions of the Thesis are summarised in Chapter 6. The future works suggested by the results of the Thesis are also presented.

Fast switching operations in IGBTs generate electromagnetic field disturbances, which might cause EMI and functionality issues. For higher frequency characterization, the parasitic inductances and capacitances have to be considered. The characterization of the electromagnetic field disturbances in- and around the converter module could be predicted early in the design. The study involves a high frequency characterization of electric fields (Efield), magnetic fields (H-fields) and the surface currents distribution in a converter module. The high frequency electromagnetic software (CST) was used for the analysis. A given 3D CAD model of an AC/DC converter module was analyzed in CST. The CAD contained IGBT bus-bars interconnections, converter casing, heat sink and other metallic structures. The ACside has six IGBTs and the DC-side has a chopper which has two switches. The IGBTs ONstate and OFF state was modeled with lumped elements. The DC link capacitor was just modeled as lumped elements, while the metallic capacitor casing was included in the 3D model for analyzing the field distribution inside the converter casing. To check the model accuracy, CST models were compared with PEEC (Partial Element Equivalent Circuit) models for simple antenna cases. Using the converter geometry, CST estimates the parasitics and the eventual current, voltage and electromagnetic field distributions for a given excitation signal. The DC-link was excited with a step pulse and the fields were computed. With consideration of specific design details, the modeling approach developed in this study, could be used to construct high frequency models of converter modules for different projects.

The widespread use of wired and wireless electronic systems has raised the level of electromagnetic pollution. For this reason, any electronic equipment and particularly those dealing with safety, should be conceived to work properly in harsh environments. In particular, power and analog front-end of a Smart Power integrated circuits (ICs) are directly exposed to the electromagnetic Interference (EMI) collected by cable harnesses, PCB traces, bonding wires and leadframes, which behaves like parasitic antennas. This PhD Thesis deals with the susceptibility of power and analog front-end circuits to EMI. Among the circuits for control and monitoring purpose, in this research work the current and temperature sensors are specifically addressed. An overview of the existing current sensor is provided. Two new methods for integrated current monitoring are presented in order to reduce the susceptibility to electromagnetic disturbances affecting the drain-source terminals of an integrated power MOS transistor. A new integrated solution for current monitoring based on Hall-effect is firstly proposed. This sensor exploits the magnetic sensitive properties of a split-drain transistor namely MagFET. The galvanic isolation between the sensor and the current to detect allows to increase the EMI immunity in current monitoring. Then, a further current sensor based on the mirror principle is described. Improved performance in terms of reactiveness and EMI immunity are shown. After that, the effect of EMI on integrated temperature sensors are investigated referring to a thermal shutdown circuit. The guidelines to improve to immunity to EMI of such circuits are given by means of simulations and experimental measurements that experienced the high reliability of the proposed temperature sensing in EMI polluted environment. The methods developed have been also used to design solutions to increase the immunity to EMI of readout front-end circuit for electronics employed in implanted circuit has been also presented. Bio-potential signals are usually monitored in current medical practice for diagnostics of several different disorders. Neural recording amplifiers that are usually employed to monitor such weak signals, can be can saturated by interference. Therefore, the effect of EMI received by the human body that behaves as an antenna, is a significant problem to specifically address.

Elektromagnetiska störningar kan orsaka stora och allvarliga problem både i land och ombord på fartyg. Störningar som kommer in i kontrollerade utrymmen via kablage kan förhindras genom speciellt framtagna kabelgenomföringar. Dock gäller att dessa är installerade korrekt och syftet med detta arbete är att ta fram en principmodell för ett portabelt kontrollinstrument för kontroll av elektromagnetisk kompatibilitet (EMC).   Genom att ta delar ur flertalet internationella standarder inom EMC-området togs en principmodell för kontrollinstrumentet fram. Genom simulering kunde delar av principen fastställas och sedan utfördes praktiska prover där testuppsättningen hade sitt ursprung i en vedertagen och beprövad uppsättning.   Proverna visade på att principmodellen fungerar. Dock uppnådde inte modellens mätenhet samma mätnoggranhet som referensinstrumentet och dämpningar i de framtagna kretsarna skiljde sig från de framräknade värdena.

I denna rapport presenteras en analys av solcellsoptimeraren med avseende på dess elektromagnetiska kompatibilitet. Syftet är att undersöka solcellsoptimerarens påverkan ur ett elektromagnetiskt kompatibilitets och interferensperspektiv. Analysen grundar sig på en kontrollmätning av en solcellsinstallation, genomförd i samarbete med Elsäkerhetsverket. I resultatet från kontrollmätningen presenteras störningsfenomen som går att härleda till optimeraren. Slutligen diskuteras överskridna krav utifrån svenska och europeiska bestämmelser.
This report presents an analysis of the solar power optimizer regarding its electromagnetic compatibility. The purpose is to investigate the effect of the solar power optimizer from an electromagnetic compatibility and interference perspective. The analysis is based on measurements of a photovoltaic installation, carried out in collaboration with the Swedish National Electrical Safety Board. The result from the measurements presents interference that can be derived from the optimizer. Finally, exceeded requirements are discussed based on Swedish and European regulations.

This thesis deals with electromagnetic compatibility of implantable electro-medical devices using in cardiology. The main aim of this thesis is detection of the resistance of implantable pacemakers (PM) and implantable cardioverter defibrillators (ICD) to the electromagnetic interference. In the first part of this thesis, a function of the heart, which is necessary for understanding of PM and ICD operation, is described. The function and construction of PM and ICD is detailed in the theoretical part as well. The next part is focused on the electromagnetic compatibility. The next part is description of the measurement method and the experimental arrangement used for practical experiments with electromagnetic resistance of PM and ICD.

L'augmentation du nombre de fonctions électriques disponibles dans les systèmes embarqués amène de nouvelles contraintes d'encombrement et de masse de leurs alimentations. Pour adresser ces problèmes, la miniaturisation et l'intégration des convertisseurs statiques sont donc des thématiques importantes de recherche qui aboutissent à de nombreuses évolutions technologiques et structurelles dont l'apparition de convertisseurs statiques à fréquence de fonctionnement élevée permettant la réduction des éléments passifs du convertisseurs.Ces avancées s'accompagnent cependant d'une augmentation des niveaux de perturbations électromagnétiques générés par le système. Afin de les diminuer, l'insertion de filtres CEM dans le système est nécessaire. Leurs performances sont fortement liées au contrôle de leurs éléments parasites. Les modèles développés jusqu'à présent concernent pour la plupart les effets conduits et l'évaluation de l'impact des phénomènes rayonnés est souvent ignoré ou au mieux basé sur des modèles simplistes. Un des objectifs de cette thèse est donc d'apporter un degré de complexification plus élevé des modèles de rayonnement des composants magnétiques utilisés dans les filtres CEM, tant par une approche par modélisation numérique que par la mise en oeuvre d'un modèle analytique.Dans un premier temps, une étude poussée du rayonnement magnétique de composants simples, les inductances toriques de mode différentiel, a été réalisée. Cette étude a débouché sur la mise en évidence des paramètres critiques déterminant la topologie du champ magnétique rayonné dans l'environnement proche du composant. Le résultat majeur de cette étude est l'importance de la répartition du bobinage autour du circuit magnétique sur le champ magnétique rayonné. De nouveaux modèles ont été proposés pour permettre la prédiction des champs proches rayonnés pour une gamme de fréquence inférieure à la résonance propre du composant.Par la suite, un modèle analytique fin du rayonnement magnétique des inductances de mode commun a été proposé. Ce modèle permet de déterminer \emph{a priori} le rayonnement magnétique proche du composant. Les études menées par la suite ont permis de relier les effets observés en rayonné au phénomènes conduits qui apparaissent dans ces composants notamment pour expliquer certains effets de transfert de mode (commun/différentiel).Dans une dernière partie, une étude de ces composants en susceptibilité électromagnétique (EM) a été menée. Elle a permis de rendre compte de l'influence d'une onde incidente de champ magnétique sur les composants étudiés et de valider les modèles proposés via une approche basée sur la réciprocité EM: la direction privilégiée de rayonnement est aussi celle de couplage facile pour un champ magnétique externe
The number of electronic devices in embedded systems is constantly increasing and their contribution to volume and weight is a major concern. In order to solve these issues, a large research effort is devoted to volume reduction and power converters' integration. This lead to constant technological evolution including the appearance of high frequency power electronic converters allowing the reduction of the volume of passive components.However, due to the increase of operating frequencies and the minimization of inter-components distances, the electromagnetic radiations generated by these systems become more important. In order to decrease this interference, EMI filters are often necessary. Their performances are often related to the value of parasitic elements in the filter which must therefore be controlled. Nonetheless most of the existing models focus on conducted electromagnetic interference (EMI) and the impact of radiated phenomena is often ignored or greatly simplified. This work will therefore focus on developing highly accurate radiation models for magnetic components commonly used in EMI filters using both numeric and analytic tools.First, the magnetic fields radiated by differential mode (MD) toroidal coils, which belong to the basic magnetic components, will be thoroughly studied. This study highlighted the critical parameters determining the near-field topology. The main result is the discovery of the impact of the winding's layout around the magnetic core on the radiated magnetic field. New models have been developed in order to predict the radiated near field.Then, an accurate analytic model of the the magnetic radiation of common-mode (CM) chokes has been developed. It allows the prediction of the magnetic near-field. The application of the model lead to the correlation between radiated phenomena and conducted effects existing in these components. The importance of the winding on CM to DM mode coupling has therefore been highlighted.Finally, the electromagnetic (EM) susceptibility of these components has been studied. This work describes the influence of an external magnetic field on the components and validates the radiation models developed using the principle of EM reciprocity. It has been shown that the easy directions are the same for both the radiated and the coupled phenomena

Le tematiche relative alla compatibilità elettromagnetica (EMC) dei dispositivi elettronici (sia per il trasferimento dell'informazione che per trasmissione e conversione di potenza) sono di grande attualità a causa di molteplici fattori. Il primo è la larga diffusione di apparecchiature elettroniche e delle telecomunicazioni in svariati ambienti. Secondariamente tali dispositivi sono sempre più suscettibili al rumore per ragioni tecniche: -tensioni di alimentazione sempre più basse (alimentazione a batterie); -aumento della velocità dei dispositivi; -miniaturizzazione; -connettività wireless (spesso con diversi protocolli sullo stesso device). All'interno di questa tesi vengono trattate le interferenze elettromagnetiche (EMI) con riferimento ad una categoria specifica di prodotti (i caricabatterie)ed approfondendo in particolare le cause e le principali tecniche per limitarne l'effetto, al fine di ottenere la compatibilità dei dispositivi. Le tecniche per abbattere le EMI presentate sono poi applicate a dispositivi commerciali per valutarne gli effetti. Il lavoro è stato svolto presso la Deca di San Marino che ha messo a disposizione un laboratorio EMC (dotato di LISN PMM L3-64, Ricevitore PMM 9010/30P full-compliance e AbsorbingClamp TESEQ) ed alcuni propri prodotti.

Until approximately 50 years ago, wireless electronics was confined to military purposes. With the advancement of technology, consumer electronics found widespread applications in almost every aspect of our lives and numerous devices were developed using electromagnetic waves to transfer different types of data. In light of such advancements, the electromagnetic compatibility (EMC) evolved from a military concept to regulate the radio frequency requirements of the battlefield equipment to a mature and essential part in manufacturing and employing electronic devices. Medical devices were no exception and largely benefited from the ease of connectivity and mobility provided by usage of wireless electronics. Due to the sensitive nature of medical devices and extreme consequences of their malfunction, EMC grew to a centric issue in design and production of such devices. This work examines the electromagnetic compatibility of a wearable biomedical measurement system used for the assessment of mental stress of combatants in real time. This system was developed as a part of the ARTEC project and supported by the Spanish Ministry of Defense through the Future Combatant program [1]. We focus on the EMC of the electrocardiogram of the system and aim to identify its EMC requirements of this system while assessing it against various standards and protocols. Throughout this study, we elucidate the fundamentals of electromagnetic compatibility with specific attention to medical devices. Furthermore, we present our results after conducting several EMC tests to measure the compatibility of the electrocardiogram device using the Intertek guidelines. The emission test was performed while essential counter measures such as appropriate shielding and anti-interference filters had been applied.

With rising fuel prices, increasing electrification, and imminent fines on CO2 emission within the EU, the requirement for energy and cost efficient supply concepts is becomingmore and more important in the automotive industry. This thesis presents an assessmentof, and improvement for energy and cost efficient power supply concepts for low-end automotiveand light e-mobility electronic control units, containing small µCs, and analogand logic components. Specifically, linear regulators, synchronous and non-synchronous buck converters, andswitched capacitor converters are investigated and assessed theoretically. The mostpromising concept, namely a discrete buck converter, is further studied using theoreticalassessment, experiment, and simulations. The key result of this work is a concept for replacing commonly used linear regulatorsin small electronic control units (ECUs) by a more efficient supply with only a smallcost adder. Specifically, since no low-end switched converter ICs are available today, wedeveloped a buck converter with discrete control circuit. This concept provides a cheap,yet efficient alternative to linear regulators for a wide range of applications. In addition,the application of this concept is supported by component selection criteria, and also bythe developed simulation models.

The scope of this thesis is the design and verification of an electronic packaging of a device which is a subunit of a network system that is designed for combat communication in sheltering ship. According to the project requirements this device is subjected to some environmental and electromagnetic interference tests. This thesis includes design and manufacturing steps as well as vibration, shock and thermal analyses. Electromagnetic interference is examined through the design procedure and total shielding effectiveness of the device is calculated after the applications of some electromagnetic interference precautions which are given in details.

Le projet de thèse s'inscrit dans le consortium industriel académique MEGAN (More Electric Gallium Nitride) réunissant de nombreux industriels français, grands groupes et PME (Renault, Schneider Electric, Safran, IDMOS, Valeo...) et académiques (G2Elab, Ampère, SATIE...) et le CEA. Le projet consiste à introduire de nouvelles technologies de composants de puissance à base de matériaux en GaN afin d'augmenter les performances des convertisseurs statiques pour divers types d'applications. La thèse est intégralement focalisée sur la partie Driver intégré de composants GaN à base d'une technologie CMOS SOI XFAB XT018 pour favoriser l'utilisation des systèmes à haute fréquence et haute température. La thèse consiste à étudier des architectures des drivers et des fonctionnalités innovantes permettant de limiter les problèmes inhérents à la haute fréquence et la haute température (Compatibilité ÉlectroMagnétique- CEM, pertes de commande par courant de fuites, limites fonctionnelles...). Suite à l'étude des architectures à l'échelle du bras d'onduleur à base de composants discrets, un circuit intégré est conçu en collaboration avec les partenaires du projet. Le circuit intégré est alors réalisé avant d'être caractérisé puis mis en œuvre dans des démonstrateurs dans le cadre du projet. En particulier, des caractéristiques de réponses en fréquence et de tenue en température seront proposées. La mise en œuvre est conduite au sein même du module de puissance intégrant les composants de puissance en GaN, au plus près de ceux-ci pour favoriser les fonctionnements à haute fréquence. Le démonstrateur final peut servir plusieurs types d'applications de part sa versatilité. Le travail de thèse est alors plus spécifiquement orienté sur l'étude du comportement haute fréquence du driver et de l'ensemble interrupteurs avec fortes vitesses de commutation / drivers d’un bras d'onduleur
This Ph.D work is part of the industrial academic project MEGaN (More Electric Gallium Nitride) involving many French companies (Renault, Schneider Electric, Safran, ID MOS, Valeo, ...), academic institutions (G2Elab, Ampere, SATIE ...) and CEA. MEGaN project aims are to introduce a new technology of the power components based on GaN materials, to increase the performance of the static converters for various applications.This research is highly focused on the integrated driver and other power device peripheral units for GaN-based components. This is done in SOI CMOS XFAB XT018 technology to promote performing in high-frequency and high temperature applications. It involves examining driver's architectures and features, innovative methods to limit problems inherent in high frequency and high temperature (conducted EMI perturbation, delay mismatch, functional limitations ...). After studying the architecture at the scale of the discrete circuits, the integrated circuits are designed in collaboration with the project partners. The integrated circuit is manufactured by foundry XFAB before being characterized and implemented.In particular, the characteristics at high frequency response and high temperature compliance are proposed. The final implementation is conducted in the hybrid power module power with the power components GaN, as close as possible to those for operation at high frequency which is presented in the end of this thesis. The final demonstrator serves several kinds of applications because of its versatility. The thesis is specifically focused on the study of high frequency behavior of the driver and power switches with high switching speed / the driver’s components of an inverter leg

Depuis une bonne dizaine d'année, l'aéronautique a entamé sa mutation vers le "plus électrique".L'objectif étant de réduire la consommation de carburant, une des contraintes majeures de ces nouvelles solutions est de réduire la masse embarquée. Les filtres dimensionnés pour les convertisseurs statiques doivent donc être optimisés au mieux vis-à-vis de ce critère, ainsi que du volume. Il y a donc un fort besoin du côté des concepteurs d’avions de savoir quels choix parmi les différentes possibilités technologiques sont optimaux, et de connaître l'impact de ces choix sur le poids, le coût global et le volume de l'équipement. Le filtre CEM représente généralement environ 30% du coût et du volume d'un convertisseur électronique de puissance. Il va de soi que le volume et/ou la masse de ces filtres doit être optimisé. L'impact de la loi de commande du convertisseur, le choix des semi-conducteurs, du packaging, câbles (longueur et intégration dans l’avion), des machines électriques,...doivent être parfaitement connus pour atteindre un dimensionnement optimal.Dans cette perspective, les objectifs de ces travaux de thèse visent à fournir non seulement une démarche méthodologique pour la modélisation haute fréquence des variateurs de vitesse dédiés aux applications aéronautiques mais aussi une approche de dimensionnement par optimisation des filtres CEM. Pour cela, un outil logiciel évolutif d’aide à la génération rapide des modèles CEM est proposé. Une description modulaire et une mise en équation automatique du modèle fréquentiel complet ainsi que des gradients en facilitent l'utilisation en procédures d’optimisation sous contraintes. L’approche présentée dans ces travaux est relativement générique : la topologie du filtre, de la structure du convertisseur, du câblage et la loi de commande peuvent être facilement recalculées, grâce à cet environnement logiciel
The More Electrical Aircraft concept is very promising regarding energy saves, but generates new problems, and especially the emergence of new power electronics loads on the electrical network. Keeping the same level of safety in the aircraft means developing these switching mode converters in accordance with the aircraft standards, as the DO160. This is not obvious since weights of equipments are especially constrained: indeed, the objective of weight and energy save needs to be balanced with the additional weight and volume of the required EMI filters. There is thus a strong need in helping the aircraft designers to choose among the various technological possibilities, and to know the impact of these choices on the global weight, cost and volume of the embedded equipments. The EMI filter usually represents roughly 30% of the cost and volume of a power electronics converter, and it is very important to optimize it. The impact of the converter control law, semiconductors choice, interconnects realization, harness selection and placement, electrical motors characteristics… should be perfectly known in order to reach a good system design. In this perspective, the objectives of this thesis are to provide not only an approach for modelling high frequency variable speed drives dedicated to aerospace applications but also a methodology to optimize the required EMI filters. For this purpose, new architecture software dedicated to the rapid generation of EMC models is proposed. A modular description and a complete automatic model generation facilitate the use by the designer in optimization procedures thanks to automatic gradient computation.The methodology presented in this work is not specifically developed for a given application. It is a very generic approach: the topology of the filter, the structure of the inverters, interconnects and the control law can be easily recalculated, using this software environment. Consequently, the impact of all these elements on the electromagnetic disturbances can be characterized, and the EMI filter optimized

This thesis reports on the investigations, simulations and analyses of novel power electronics topologies and control strategies. The research is financed by an Australian Research Council (ARC) Linkage (07-09) grant. Therefore, in addition to developing original research and contributing to the available knowledge of power electronics, it also contributes to the design of a DC-DC converter for specific application to the auxiliary power supply in electric trains. Specifically, in this regard, it contributes to the design of a 7.5 kW DC-DC converter for the industrial partner (Schaffler and Associates Ltd) who supported this project. As the thesis is formatted as a ‘thesis by publication’, the contents are organized around published papers. The research has resulted in eleven papers, including seven peer reviewed and published conference papers, one published journal paper, two journal papers accepted for publication and one submitted journal paper (provisionally accepted subject to few changes). In this research, several novel DC-DC converter topologies are introduced, analysed, and tested. The similarity of all of the topologies devised lies in their ‘current circulating’ switching state, which allows them to store some energy in the inductor, as extra inductor current. The stored energy may be applied to enhance the performance of the converter in the occurrence of load current or input voltage disturbances. In addition, when there is an alternating load current, the ability to store energy allows the converter to perform satisfactorily despite frequently and highly varying load current. In this research, the capability of current storage has been utilised to design topologies for specific applications, and the enhancement of the performance of the considered applications has been illustrated. The simplest DC-DC converter topology, which has a ‘current circulating’ switching state, is the Positive Buck-Boost (PBB) converter (also known as the non-inverting Buck-Boost converter). Usually, the topology of the PBB converter is operating as a Buck or a Boost converter in applications with widely varying input voltage or output reference voltage. For example, in electric railways (the application of our industrial partner), the overhead line voltage alternates from 1000VDC to 500VDC and the required regulated voltage is 600VDC. In the course of this research, our industrial partner (Schaffler and Associates Ltd) industrialized a PBB converter–the ‘Mudo converter’–operating at 7.5 kW. Programming the onboard DSP and testing the PBB converter in experimental and nominal power and voltage was part of this research program. In the earlier stages of this research, the advantages and drawbacks of utilization of the ‘current circulating’ switching state in the positive Buck-Boost converter were investigated. In brief, the advantages were found to be robustness against input voltage and current load disturbances, and the drawback was extra conduction and switching loss. Although the robustness against disturbances is desirable for many applications, the price of energy loss must be minimized to attract attention to the utilization of the PBB converter. In further stages of this research, two novel control strategies for different applications were devised to minimise the extra energy loss while the advantages of the positive Buck-Boost converter were fully utilized. The first strategy is Smart Load Controller (SLC) for applications with pre-knowledge or predictability of input voltage and/or load current disturbances. A convenient example of these applications is electric/hybrid cars where a master controller commands all changes in loads and voltage sources. Therefore, the master controller has a pre-knowledge of the load and input voltage disturbances so it can apply the SLC strategy to utilize robustness of the PBB converter. Another strategy aiming to minimise energy loss and maximise the robustness in the face of disturbance is developed to cover applications with unexpected disturbances. This strategy is named Dynamic Hysteresis Band (DHB), and is used to manipulate the hysteresis band height after occurrence of disturbance to reduce dynamics of the output voltage. When no disturbance has occurred, the PBB converter works with minimum inductor current and minimum energy loss. New topologies based on the PBB converter have been introduced to address input voltage disturbances for different onboard applications. The research shows that the performance of applications of symmetrical/asymmetrical multi-level diode-clamped inverters, DC-networks, and linear-assisted RF amplifiers may be enhanced by the utilization of topologies based on the PBB converter. Multi-level diode-clamped inverters have the problem of DC-link voltage balancing when the power factor of their load closes to unity. This research has shown that this problem may be solved with a suitable multi-output DC-DC converter supplying DClink capacitors. Furthermore, the multi-level diode-clamped inverters supplied with asymmetrical DC-link voltages may improve the quality of load voltage and reduce the level of Electromagnetic Interference (EMI). Mathematical analyses and experiments on supplying symmetrical and asymmetrical multi-level inverters by specifically designed multi-output DC-DC converters have been reported in two journal papers. Another application in which the system performance can be improved by utilization of the ‘current circulating’ switching state is linear-assisted RF amplifiers in communicational receivers. The concept of ‘linear-assisted’ is to divide the signal into two frequency domains: low frequency, which should be amplified by a switching circuit; and the high frequency domain, which should be amplified by a linear amplifier. The objective is to minimize the overall power loss. This research suggests using the current storage capacity of a PBB based converter to increase its bandwidth, and to increase the domain of the switching converter. The PBB converter addresses the industrial demand for a DC-DC converter for the application of auxiliary power supply of a typical electric train. However, after testing the industrial prototype of the PBB converter, there were some voltage and current spikes because of switching. To attenuate this problem without significantly increasing the switching loss, the idea of Active Gate Signalling (AGS) is presented. AGS suggests a smart gate driver that selectively controls the switching process to reduce voltage/current spikes, without unacceptable reduction in the efficiency of switching.

碩士
元智大學
通訊工程學系
93
The finite-difference time-domain (FDTD) method is used to study the electric fields coupling into a vehicle exposed to lightning electromagnetic pulse (LEMP) waves. Currents and Maximum Current densities induced in human bodies sitting inside a vehicle exposed to LEMP waves are also investigated by the FDTD method at frequencies from 10 MHz to 50 MHz. From simulation results of electric fields coupling into a vehicle, it is found that the maximum shielding effect of about 72.5% occurred inside the vehicle. The shielding effect can be highly improved by implementing a good conducting material in the windshield and auto glass. Inside the vehicle, it is also found that there are various reflections around the vehicle’s body due to the influence of the vehicle structure on the incident LEMP waves. From simulation results of currents induced in human bodies, it is found that the induced current density in the driver’s body increases as the frequency increases from 10 Hz to 50 MHz. Obtained maximum current densities of 0.01~0.8 A/cm2 at 50 MHz induced in human bodies for different numbers of persons are much higher than the threshold current density of 1microA/cm2 for the steady-state current flow cases, which may cause biological effects that are harmful to health. However, the specific absorption (SA) for different number of persons sitting inside in the vehicle are considerably smaller than the value of 28.8 J/kg whole-body-averaged SA per pulse that has been proposed for the 1992 revision of ANSIC/IEEE C95.1-1992 Peak Power Exposure.

碩士
大葉大學
電機工程研究所
90
This thesis will discuss the variation of RE measurement in different sites between OATS and manufacturing factory. The principle is to build a standard signal source to generate a broadband interference, then to measure the interference in OATS and manufacturing factory in order to analyze the deviation between two sites. This method also presented some statistical data for calculating a very useful correction factor which can correct the data of RE measurement in situ. After correcting, the measurement inaccuracy can be reduced from 12.9dB to 4dB.

碩士
大葉大學
電信工程學系碩士在職專班
94
Taiwan machine tool production in 2004 has raised to the amount NT$96,500 million owing to the demand Mainland China market. This is the highest amount over the recent years and in turn pushes Taiwan global rank to fifth position. However, the design, research and development of industrial mechanical equipment are facing the same problem. These problems at hand, are designing different kind of electronic equipment compatible on one machine functioning properly simultaneously without compromising the individual efficiency as well as interfering with the normal function of other electronic elements and the question of electromagnetic compatibility (EMC). This thesis will discuss the variation of RE measurement in different sites between OATS and manufacturing factory. The principle is to build a standard signal source to generate a broadband interference, then to measure the interference in OATS and manufacturing factory in order to analyze the deviation between two sites. This method also presented some statistical data for calculating a very useful correction factor which can correct the data of RE measurement in situ. After correcting, the measurement inaccuracy can be reduced from 19.25dB to 4dB.

碩士
元智大學
通訊工程學系
93
The finite-difference time-domain (FDTD) method is used to study electric fields distributions on the printed circuit board (PCB) built in a wireless local area network (WLAN) communication unit. In the simulation of the PCB and WLAN communication unit, an equivalent material obtained by the effective material property technique is considered to model the metallic material, epoxy resin substrates of PCBs, cable and air. Simulation results of electric field distributions on the PCB are presented and compared with those obtained from measurement data for an opened metallic case of the WLAN communication unit. From simulation results, it is found that maximum electric fields on a test plane over the PCB with a height of 1 and 2 cm are obtained to be 0.25~0.32 and 0.15~0.25 V/m for the RF power of 17.2 dBm at 2.4 GHz under the condition of an opened WLAN communication unit, respectively. Comparing measurement data of electric field distributions on test planes with a height of 1 and 2 cm over the PCB, with those obtained by FDTD simulations, it is found that simulation results make a good agreement with measurement data for an opened WLAN communication unit. From simulation results, it is also found that a resonant effect with a factor of 2 in the magnitude of electric fields on a test plane with a height of 1 cm over the PCB occurs for a closed WLAN communication unit.

With the increasing demand of higher operating frequencies for electronic circuits, the printed circuit board designers face more electromagnetic radiation problems than ever. Some “rules-of-thumb” are employed to help the designers to reduce the radiation problems. The 20H rule is one of printed circuit design rules, which intends to minimize the electromagnetic radiation. This project focuses on analysis and simulation of 20H rule’s signal propagation mechanisms. The model used in the project is a 2D planar structure. The numerical electromagnetic method, Finite Difference Time Domain (FDTD) method, is used for the field computation and analysis. Simulation is based on various structures of model and different distributions of excitation sources. Analysis focuses on the signal propagation models. Field distributions and radiation patterns are visualized by mathematical software. Meanwhile, Poynting vectors are calculated to give quantitative expression. The simulation results indicate three factors, namely, operating frequency, size of PCB and separation distance that will affect the function of 20H rule. The effects of three factors are shown by comparison of specific cases in this thesis.
Singapore-MIT Alliance (SMA)

碩士
大同大學
機械工程學系(所)
94
The study purpose of this article is research in those common industry chassis of network and communication at present, it cuts the size of radiation network hole in the industry chassis which has the best choice of the shape and the way of arrangement to the result of control in the EMI/EMC. Why I do this research is because of electromagnetic wave that becomes seriously injury problem to people’s body & health so much today, and people face this problem now already more and more. But, so far, in industry chassis market, there is not so many articles were issued on it. So, in the thesis, we use the standard laboratory and instruments of EMI/EMC to proceed the serial tests of Square & Circular holes with many sizes and permutation of the normally specs in the industry chassis market. From these models, we can to understand the simulate status in the frequencies of 300kHz∼1GHz and their true effects of the EMI/EMC. After a Series of experiment, we can know that the types and sizes of holes that the way of cover efficiency on circular holes is better than square holes! Thus, it interests me to study this subject, and also I would like to present some my personal idea to the people who is interesting the same project reference.

Ο σκοπός αυτής της εργασίας είναι να προωθηθεί ένας οδηγός σχετικά με τις κατασκευαστικές προδιαγραφές και την απόδοση των ηλεκτρομαγνητικών ανηχοικών θαλάμων και των εσωτερικών εγκαταστάσεων δοκιμής. Εντούτοις, απαιτείται κάποια γνώση ηλεκτρομαγνητικών μετρήσεων, για να εξασφαλιστεί ότι όλοι οι εφαρμόσιμοι κατασκευαστικοί παράγοντες, έχουν εφαρμοστεί στις καταστάσεις που θα ζητηθούν. Η μέτρηση των ηλεκτρομαγνητικών κυμάτων περιλαμβάνει μεγάλο αριθμό ηλεκτρονικών συσκευών. Αυτές οι συσκευές μπορούν να ταξινομηθούν σε άμεσους ή σε έμμεσους εκπομπούς. Η μέτρηση των άμεσων εκπομπών (όπως οι κεραίες) ή η εκπομπή της ηλεκτρομαγνητικής ενέργειας, όπως στη διατομή του ραντάρ, απαιτεί εξειδικευμένες εγκαταστάσεις. Ο καθορισμός του επιπέδου ακτινοβολίας από τους έμμεσους εκπομπούς όπως οι ψηφιακές συσκευές ή ο καθορισμός του επιπέδου «ευαισθησίας» που έχει μια ηλεκτρονική συσκευή, όσον αφορά ένα εισερχόμενο ηλεκτρομαγνητικό κύμα περιλαμβάνει επίσης τη μέτρηση των ηλεκτρομαγνητικών κυμάτων στις εγκαταστάσεις που σχεδιάζονται συγκεκριμένα για τη μέτρηση που πραγματοποιείται. Ηλεκτρομαγνητικό κύμα είναι το αποτέλεσμα από την επιτάχυνση των ηλεκτρικών φορτίων. Το ηλεκτρικό πεδίο λόγω μιας ανεπιθύμητης φόρτισης (σε κάποια δοκιμή ή στην ομοιόμορφη κίνηση σε μια ευθεία γραμμή) κατευθύνεται ακτινωτά και μειώνεται ως το τετράγωνο της απόστασης από τη φόρτιση. Εντούτοις, η επιτάχυνση της φόρτισης προκαλεί αύξηση του ηλεκτρικού πεδίου, και μειώνεται γραμμικά με την απόσταση. Στην πράξη, σχεδόν πάντα υπάρχει ενδιαφέρον για τα μακροσκοπικά αποτελέσματα. Στην μακροσκοπική κλίμακα, η αλληλεξάρτηση μεταξύ των ηλεκτρικών και μαγνητικών πεδίων περιγράφεται από μαθηματική άποψη από τις εξισώσεις Maxwell [ 2 ..3 ]. Τα μαθηματικά των ηλεκτρομαγνητικών πεδίων και των σχετικών μέσων χρησιμοποιούν την διανυσματική ανάλυση. Η ανάλυση μπορεί να αναμιχθεί πολύ, σε πολλά προβλήματα, ειδικά εκείνα που περιλαμβάνουν τη διάδοση στα μη ισοτροπικά , μη-αμοιβαία, μη γραμμικά, ή ανομοιογενή μέσα. Αν και ορισμένα προβλήματα στις ηλεκτρομαγνητικές μετρήσεις μπορούν να απαιτήσουν την εφαρμογή πιο λεπτομερών μαθηματικών. Στους ανηχοικούς θαλάμους πραγματοποιούνται δύο ειδών δοκιμές, η δοκιμή ηλεκτρομαγνητικής παρεμβολής (EMI) και η δοκιμή ηλεκτρομαγνητικής συμβατότητας (EMC). Ηλεκτρομαγνητική παρεμβολή (EMI) είναι κάθε σήμα ή εκπομπή που ακτινοβολείται στον χώρο ή άγεται σε καλώδια τροφοδοσίας ή σημάτων και θέτει σε κίνδυνο τη λειτουργία συστημάτων ασύρματης πλοήγησης ή άλλες υπηρεσίες ασφαλείας ή υποβαθμίζει, παρεμποδίζει ή διακόπτει επανειλημμένα μια αδειοδοτημένη υπηρεσία ασύρματων επικοινωνιών. Στις υπηρεσίες ασυρμάτων επικοινωνιών περιλαμβάνονται, ενδεικτικά, οι εμπορικές εκπομπές AM/FM, η τηλεόραση, η κινητή τηλεφωνία, τα ραντάρ, ο έλεγχος εναέριας κυκλοφορίας, η τηλεειδοποίηση και οι Υπηρεσίες Προσωπικής Επικοινωνίας (Personal Communication Services ή PCS). Αυτές οι αδειοδοτημένες και οι μη αδειδοτημένες υπηρεσίες ασυρμάτων επικοινωνιών, όπως το WLAN ή το Bluetooth, μαζί με ακούσιους πομπούς όπως ψηφιακές συσκευές, συμπεριλαμβανομένων συστημάτων υπολογιστών, συμβάλλουν στο ηλεκτρομαγνητικό περιβάλλον. Η ηλεκτρομαγνητική συμβατότητα (ΗΜΣ) είναι η δυνατότητα στοιχείων του ηλεκτρονικού εξοπλισμού να λειτουργούν ομαλά μαζί, μέσα σε ηλεκτρονικό περιβάλλον. Παρόλο που το συγκεκριμένο σύστημα υπολογιστή έχει σχεδιαστεί και έχει προσδιοριστεί ως συμβατό με τα όρια που καθορίζονται από το φορέα κανονισμών για ηλεκτρομαγνητικές παρεμβολές, δεν παρέχεται κανενός είδους εγγύηση ότι δεν θα υπάρξει παρεμβολή σε μία συγκεκριμένη εγκατάσταση. Τα προϊόντα της EMC Corporation είναι σχεδιασμένα, ελεγμένα και κατηγοριοποιημένα σύμφωνα με το συγκεκριμένο ηλεκτρομαγνητικό περιβάλλον χρήσης τους. Αυτές οι κατηγορίες ηλεκτρομαγνητικού περιβάλλοντος αναφέρονται γενικά στους ακόλουθους εναρμονισμένους ορισμούς: • Τα προϊόντα κατηγορίας B προορίζονται για χρήση σε οικιακά περιβάλλοντα, αλλά μπορούν επίσης να χρησιμοποιηθούν σε μη οικιακά περιβάλλοντα. Σημείωση: Οικιακό περιβάλλον είναι ένα περιβάλλον όπου η χρήση πομπών ραδιοσυχνοτήτων και τηλεοπτικών δεκτών μπορεί να είναι αναμενόμενη σε απόσταση 10 m από το σημείο που χρησιμοποιείται το προϊόν. • Τα προϊόντα κατηγορίας A προορίζονται για χρήση σε μη οικιακά περιβάλλοντα. Τα προϊόντα κατηγορίας A μπορούν επίσης να χρησιμοποιηθούν σε οικιακά περιβάλλοντα, αλλά ενδέχεται να προκαλέσουν παρεμβολές και να απαιτηθεί η λήψη διορθωτικών μέτρων από το χρήστη. Εάν αυτός ο εξοπλισμός προκαλέσει παρεμβολή σε υπηρεσίες ραδιοεπικοινωνιών, η οποία παρεμβολή διαπιστώνεται ενεργοποιώντας και απενεργοποιώντας τον εξοπλισμό, επιχειρήστε να διορθώσετε την παρεμβολή ενεργώντας ως εξής: • Επαναπροσανατολισμός της κεραίας λήψης. • Αλλαγή θέσης του υπολογιστή σε σχέση με το δέκτη. • Μετακίνηση του υπολογιστή μακριά από το δέκτη. • Σύνδεση του υπολογιστή σε διαφορετική πρίζα έτσι ώστε ο υπολογιστής και ο δέκτης να βρίσκονται σε διαφορετικά κυκλώματα. Εάν είναι απαραίτητο, επικοινωνήστε με έναν τεχνικό υποστήριξης της EMC Corporation ή κάποιο εξειδικευμένο τεχνικό ραδιοφώνων/τηλεοράσεων ή ειδικό ΗΜΣ για περαιτέρω υποδείξεις. Ο εξοπλισμός τεχνολογίας πληροφοριών (ITE) που περιλαμβάνει περιφερειακά όπως κάρτες επέκτασης, εκτυπωτές, συσκευές εισόδου/εξόδου (I/O), οθόνες κ.λπ., και οι οποίες είναι ενσωματωμένες μέσα στο σύστημα ή συνδεδεμένες σε αυτόν, πρέπει να συμμορφώνεται με την κατηγορία ηλεκτρομαγνητικού περιβάλλοντος του υπολογιστή.
The purpose of this paper is to provide a guide on the design and performance specification of electromagnetic anechoic chambers or indoor test facilities. However, some knowledge of electromagnetic measurements is required to ensure that all applicable design factors have been applied in any given design situation. The measurement of electromagnetic waves involves a large number of electronic devices. These devices can be categorized as intentional or unintentional radiators. Measurement of intentional radiators (such as antennas) or the scattering facilities. Determining the level of radiation from unintentional radiators such as digital devices or determining the level of immunity an electronic device has with respect to an impinging electromagnetic wave also involves the measurement of electromagnetic waves in testing facilities designed specifically for the measurement to be performed. Electromagnetic waves result from the acceleration of electric charges. The electric field due to an unaccelerated charge (one at rest or in uniform motion in a straight line) is radially directed and decreases as the square of the distance from the charge. However, the acceleration of the charge gives rise to a tangential component of the electric field, and this decreases linearly with distance. This time-varying electric field has associated with it a time varying magnetic field, together, they comprise an electromagnetic field. An electromagnetic field that decreases linearly with distance represents an outward radiation. In practice, one is almost always concerned with macroscopic effects resulting from acceleration of gross numbers of charges. On the macroscopic scale, the interrelationship between electric and magnetic fields is described mathematically by Maxwell’s equations. An additional set of equations called constitutive relationships specifies the characteristics of the medium in which the field exists. The mathematics of electromagnetic fields and the associated media makes use of vector and tensor analysis. The analysis can become very involved in many problems, especially those involving propagation in nonisotropic, nonreciprocal, nonlinear, or nonhomogeneous media. Although certain problems in electromagnetic measurements can require application of more detailed mathematics. In anechoic chambers, take place two types of tests, the electromagnetic interference test (EMI) and the electromagnetic compatibility testing (EMC). Electromagnetic interference (EMI) is any signal or emission radiated in space or is induced in cables or signals and threatening the operation of wireless navigation services or other security or degrade, obstruct or repeatedly interrupts a licensed radio communications service. In wireless communications services including, without limitation, commercial broadcasting AM / FM, TV, mobile telephony, radar, air traffic control, paging and personal communications services (Personal Communication Services or PCS). These licensed and non licensed wireless communications such as WLAN or Bluetooth, along with unintentional transmitters such as digital devices, including computer systems, contribute to the electromagnetic environment. The electromagnetic compatibility (EMC) is the potential components of electronic equipment to operate seamlessly together in an electronic environment. While this computer system has been designed and determined to be compatible with the limits set by the service regulations for electromagnetic interference, there is no guarantee that interference will not occur in a particular installation. Its products are EMC Corporation is designed, tested and categorized according to the specific electromagnetic environment of use. These types of electromagnetic environment generally refers to the following harmonized definitions: • Products category B for use in domestic environments, but can also be used in non-domestic environments. Note: the domestic environment is an environment where the use of RF transmitters and television receivers may be expected within 10 m from where the product is used. • Class A products are intended for use in non-domestic environments. Class A products can also be used in domestic environments, but it may cause interference and require remedial action by the user. If this equipment cause interference to radio services, which insert shows activating and disabling the equipment, try to correct the interference by acting as follows: • Reorient the receiving antenna. • Relocating the computer to the receiver. • Move the computer away from the receiver. • Connect the computer into a different outlet so that computer and receiver are on different circuits. If necessary, contact technical support EMC Corporation or any qualified radio / TV technician or special EMC for further instructions. Information technology equipment (ITE), including peripherals such as expansion cards, printers, input / output (I / O), monitors, etc., which are embedded in the system or connected to it, must comply with Category electromagnetic environment of the computer.

With advances in technology and increased design complexity in the automotive industry, Electromagnetic Interference (EMI) and Electromagnetic Compatibility (EMC) issues are becoming increasingly important. An accurate system level analysis is required from an early design stage to detect and mitigate problems at the initial stage. The major difficulty encountered in automotive simulation is to deal with different geometric scales, ranging from a fraction of wavelengths (Printed Circuit Board) to multiple wavelengths (harness). When the problem size becomes larger, traditional full wave solvers like Finite Element Method (FEM), Method of Moment (MoM) or Finite Time Domain Difference (FDTD) lose their efficiency as calculation of domain interactions become computationally costly. There is an opportunity to combine different solvers in a hybrid framework to efficiently analyze such system-level problems. This thesis addresses the challenge and proposes different modelling and simulation methods for EMC test setups using a hybrid approach. The first part of this work is an efficient 2.5D solver development for power distribution network (PDN) analysis of automotive boards. Design of power ground layout of a multi-layered Printed Circuit Board (PCB) is crucial for low noise and stable power supply. 2.5D tools are better suited for early stage PDN analysis over 3D full-wave electromagnetic solvers due to faster simulation times. In this work, a non-orthogonal 2.5D PEEC formulation is proposed, employing quadrilateral mesh elements for efficient simulation of the PDN. Individual stamps for resistance, inductance, capacitance and conductance elements for a unit quadrilateral cell are derived. Further, the methodology is enhanced to capture coplanar coupling through introduction of mutual inductance and capacitive terms between neighboring PEEC cell-pairs. Numerical results demonstrate good accuracy compared to a 3D full-wave commercial tool for layered PCB geometries. The efficiency of the proposed method is benchmarked against commercial solvers. The second part of the work is focused on the model-based simulation methodology for system-level immunity characterization at an early design stage. The Bulk Current Injection (BCI) method is one of the commonly used immunity test for automotive ICs. In this test, a common mode RF current of a specified value is injected into the cable harness using an injection clamp. The DUT functionality is monitored under this RF disturbance over a frequency range typically up to 400 MHz. The simulation framework for BCI test is comprised of a hybrid 2D-3D electromagnetic solver and a circuit solver. First, an accurate circuit model of injection clamp with multiple cables is developed. Although, there are circuit models reported in literature for clamps with a single cable, they do not directly lend themselves to multiple cable formulation. The proposed clamp model is validated with measurements. Then, IC immunity model (ICIM) is inducted into the simulation environment to accurately predict the immunity behavior of an IC. The proposed method is validated by comparing the simulation prediction with the actual BCI measurement. Finally, an approach comprising of Method of Moments and Harmonic Balance method is used to capture the non-linear response of active elements like transistors or diodes in an automotive board. It is demonstrated that a traditional Harmonic Balance approach will fail at high noise voltage levels which may be a likely scenario in many BCI tests with high injection clamp current specifications. A Line-Search intermediate step is introduced to address this issue. Numerical results demonstrate that the proposed method converges to accurate results faster. The third problem is focused on improving the simulation efficiency of a radiation emission (RE) test bench in the automotive application. As the device under test (DUT) and the measuring antenna are electrically far apart, the back scattered field from the antenna is quite minimal and can be neglected. By using the unidirectional coupling between these domains, a substantial reduction in memory requirements and computational time can be achieved in comparison to traditional multi-domain hybrid FEM-MoM. Also further speed up is achieved by reusing the domain-to-domain interaction terms. Next part of this research is focused in finding the source of radiation in the emissions setup. The source of radiation can be from common mode current on the cable harness or from the DUT. A method based on Huygens box is proposed to quantify the radiation from cable and DUT at each frequency. On each cell of the Huygens box the value of electric field computed at the observation point taking the Electric Current (J) and Magnetic Current (M) on that cell as sources and this information on the Huygens box is used to quantify the radiation. Some part of the presented work is used at Simyog, an IISc incubated start-up, to develop a simulation software called Compliance-Scope which allows the designer to predict the EMI/EMC performance of electronic hardware modules at an early design stage