The objective of this dissertation is to develop electrical modeling and co-simulation methodologies for signal and power integrity of package and board applications. The dissertation includes 1) the application of the finite element method to the optimization for decoupling capacitor selection and placement on a power delivery network (PDN), 2) the development of a PDN modeling method effective for multidimensional and multilayer geometries, 3) the analysis and modeling of return path discontinuities (RPDs), and 4) the implementation of the absorbing boundary condition for PDN modeling. The optimization technique for selection and placement of decoupling capacitors uses a genetic algorithm (GA) and the multilayer finite element method (MFEM), a PDN modeling method using FEM. The GA is customized for the decoupling problem to enhance the convergence speed of the optimization. The mathematical modifications necessary for the incorporation of the capacitor model into MFEM is also presented. The main contribution of this dissertation is the development of a new modeling method, the multilayer triangular element method (MTEM), for power/ground planes of a PDN. MTEM creates a surface mesh on each plane-pair using dual graphs; a non-uniform triangular mesh (Delaunay triangulation) and its orthogonal counterpart (Voronoi diagram), to which electromagnetic and equivalent circuit concepts are applied. The non-uniform triangulation is especially efficient for discretizing multidimensional and irregular geometries which are common in package and board PDNs. Moreover, MTEM generates a sparse, banded, and symmetric system matrix, which enables efficient computations. For a given plane-pair, MTEM extracts an equivalent circuit that is consistent with the physics-based planar-circuit model of a plane-pair. Thus, the values of the lumped elements can be simply calculated from the physical parameters, such as material properties and mesh geometries of each unit-cell. Consequently, the modeling of MTEM is flexible and easy to modify for further extensions, such as the incorporation of external circuits, e.g. decoupling capacitors and vertical interconnects. Power and ground planes provide paths for the return current of signal traces. Typically, planes have discontinuities such as via holes, plane cutouts, and split planes that disturb flow of signal return currents. At the discontinuity, return currents have to detour or switch to different layers, causing signal and power integrity problems. Therefore, a separate analysis of signal interconnects will neglect the significant coupling with a PDN, and the result will not be reliable. In this dissertation, the co-simulation of the signal and power integrity is presented focusing on the modeling of RPDs created by split planes, apertures, and vias. Plane resonance is one of the main sources of power integrity problems in package and board PDNs. A number of techniques have been developed and published in literature to reduce or prevent the resonance of a plane-pair. One of the techniques is to surround plane-pair edges with absorbing material that effectively damps the outgoing parallel-plate wave and minimizes the reflection. To model this behavior, the boundary condition of MTEM needs to be changed from its original form, the open-circuit boundary condition. In this dissertation, the application of the 1st order absorbing boundary condition to MTEM is presented.

Water distribution network models are widely used for various purposes such as long-range planning, design, operation and water quality management. Before these models are used for a specific study, they should be calibrated by adjusting model parameters such as pipe roughness values and nodal demands so that models can yield compatible results with site observations (basically, pressure readings). Many methods have been developed to calibrate water distribution networks. In this study, Darwin Calibrator, a computer software that uses genetic algorithm, is used to calibrate N8.3 pressure zone model of Ankara water distribution network / in this case study the network is calibrated on the basis of roughness parameter, Hazen Williams coefficient for the sake of simplicity. It is understood that there are various parameters that contribute to the uncertainties in water distribution network modelling and the calibration process. Besides, computer software&rsquo / s are valuable tools to solve water distribution network problems and to calibrate network models in an accurate and fast way using automated calibration technique. Furthermore, there are many important aspects that should be considered during automated calibration such as pipe roughness grouping. In this study, influence of flow velocity on pipe roughness grouping is examined. Roughness coefficients of pipes have been estimated in the range of 70-140.

The clock is the important synchronizing element in all synchronous digital systems. The difference in the clock arrival time between sink points is called the clock skew. This uncertainty in arrival times will limit operating frequency and might cause functional errors. Various clock routing techniques can be broadly categorized into 'balanced tree' and 'fixed mesh' methods. The skew and delay using the balanced tree method is higher compared to the fixed mesh method. Although fixed mesh inherently uses more wire length, the redundancy created by loops in a mesh structure reduces undesired delay variations. The fixed mesh method uses a single mesh over the entire chip but it is hard to introduce clock gating in a single clock mesh. This thesis deals with the introduction of 'reconfigurability' by using control structures like transmission gates between sub-clock meshes, thus enabling clock gating in clock mesh. By using the optimum value of size for PMOS and NMOS of transmission gate (SZF) and optimum number of transmission gates between sub-clock meshes (NTG) for 4x4 reconfigurable mesh, the average of the maximum skew for all benchmarks is reduced by 18.12 percent compared to clock mesh structure when no transmission gates are used between the sub-clock meshes (reconfigurable mesh with NTG =0). Further, the research deals with a ‘modified zero skew method' to connect synchronous flip-flops or sink points in the circuit to the clock grids of clock mesh. The wire length reduction algorithms can be applied to reduce the wire length used for a local clock distribution network. The modified version of ‘zero skew method’ of local clock routing which is based on Elmore delay balancing aims at minimizing wire length for the given bounded skew of CDN using clock mesh and H-tree. The results of ‘modified zero skew method' (HC_MZSK) show average local wire length reduction of 17.75 percent for all ISPD benchmarks compared to direct connection method. The maximum skew is small for HC_MZSK in most of the test cases compared to other methods of connections like direct connections and modified AHHK. Thus, HC_MZSK for local routing reduces the wire length and maximum skew.

In this thesis, the conventional low voltage power line communication methods is investigated in the axis of automated meter reading applications and the classification and experimental verification of common noise types for low voltage power line communication network. The investigated system provides the real time transmission of electricity consumption data recorded by electricity meters, initially to a local computer via a low voltage line through a low speed PLC (Power Line Carrier) environment and subsequently to a corporate network through a high speed data transmission medium. The automated meter system provides a more effective tracking and data acquisition, a more detailed and vigorous knowledge about consumer behavior for subscriber assessment in electricity distribution in association with a brand new management and system supervision concept in electricity distribution control and management technology. The theoretical studies are experimentally verified for the Turkish low voltage power infrastructure through laboratory experiments performed in METU Electrical and Electronics Engineering Department, Electrical Machines and Drives Laboratory and R&amp / D Laboratories of MAKEL facilities in Hadimk&ouml / y. The single phase voltage of the mains line between the phase and neutral is monitored to exhibit the disturbing effects of various noise sources. The resulting voltage spectrum is logged by using digital data acquisition devices in time and frequency domain. The waveforms are converted to frequency domain using the Fast Fourier Transform (FFT) functions of the MATLAB. The experimental results are compared to the theoretical findings obtained through literature survey.

Power supply noise, which is the variation in the supply voltage across the on-die supply terminals of VLSI circuits, is a serious performance degrader in digital circuits and mixed analog-digital circuits. In digital VLSI systems, power supply noise causes timing errors such as delays, jitter, and false switching. In microprocessors, power supply noise reduces the maximum operating frequency (FMAX) of the CPU. In mixed analog-digital circuits, power supply noise manifests as the substrate noise and impairs the performance of the analog portion. The decrease in the available noise margin with the decrease in the feature size of transistors in CMOS systems makes the power supply noise a very serious issue, and demands new methods to reduce the power supply noise in sub-micron CMOS systems. In this thesis, we develop a new method to determine optimal time-delays between the switching of input/output (I/O) data buffers in digital VLSI systems that realizes maximum reduction of the power supply noise. We first discuss methods to characterize the distributed nature of the Power Delivery Network (PDN) in the frequency-domain. We then develop an analytical method to determine the optimal delays using the frequency-domain response of the PDN and the supply current spectrum of the buffer units. We explain the mechanism behind the cancellation of the power supply noise by the introduction of optimal buffer-to-buffer delays. We also develop a numerical method to determine the optimal delays and compare it with the analytical method. We illustrate the reduction in the power supply noise by applying the optimal time-delays determined using our methods to two examples of PDN. Our method has great potential to realize maximum reduction of power supply noise in digital VLSI circuits and substrate noise in mixed analog-digital VLSI circuits. Lower power supply noise translates into lower cost and improved performance of the circuit.

Temporal and spatial distribution of incoming vehicular charging demand is a significant challenge for the future planning of power systems. In this thesis the vehicular loading is-sue is categorized into two classes of stationary and mobile; they are then addressed in two phases. The mobile vehicular load is investigated first; a location-based forecasting algorithm for the charging demand of plug-in electric vehicles at potential off-home charging stations is proposed and implemented for real-world case-studies. The result of this part of the re-search is essential to realize the scale of fortification required for a power grid to handle vehicular charging demand at public charging stations. In the second phase of the thesis, a novel decentralized control strategy for scheduling vehicular charging demand at residential distribution networks is developed. The per-formance of the proposed algorithm is then evaluated on a sample test feeder employing real-world driving data. The proposed charging scheduling algorithm will significantly postpone the necessity for upgrading the assets of the network while effectively fulfilling customers’ transportation requirements and preferences. / October 2014

Clock Distribution Networks play a vital role in performance and reliability of a system. However, temperature gradients observed in 3D ICs hamper the functionality of CDNs in terms of varying skew and propagation delay. This thesis presents two compensation techniques, Adaptive Voltage and Controllable Delay, to overcome these problems. The compensation methods are validated using a FPGA-based test vehicle. Modification in traditional buffer design are also presented and the performance as well as the area and power overhead of both the implementations is compared.

Στην παρούσα Διπλωματική Εργασία μελετάται και αναλύεται η Ηλεκτρομαγνητική συμπεριφορά βασικών κυκλωμάτων και στοιχείων, τα οποία απαντώνται πάνω σε Πλακέτες Τυπωμένων Κυκλωμάτων. Η σχεδίαση και ανάλυση των μοντέλων γίνεται χρησιμοποιώντας τα Ηλεκτρομαγνητικά λογισμικά πακέτα της Agilent, ΕΜPro και ADS, ενώ για τον υπολογισμό χρήσιμων παραμέτρων χρησιμοποιείται η ελεύθερη εφαρμογή της Agilent, Appcad και η εφαρμογή Linecalc, η οποία είναι ενσωματωμένη στο ADS. Αρχικά, γίνεται μια σύντομη αναφορά στις σύγχρονες τάσεις που επικρατούν στην περιοχή των Τυπωμένων Κυκλωμάτων και περιγράφεται η χρησιμότητα των τοπολογιών που αναλύονται. Επιπροσθέτως, αναφέρεται η αναγκαιότητα και οι περιπτώσεις κατά τις οποίες είναι απαραίτητη η διεξαγωγή ηλεκτρομαγνητικής ανάλυσης των κυκλωμάτων, αλλά και τα προτερήματα που αυτή προσφέρει. Παρουσιάζεται η χρησιμότητα και αναλύεται η δομή μιας μαιανδρικής μικροταινιακής γραμμής εισαγωγής καθυστερήσεως και συγκρίνονται οι εκπομπές της ως προς τις εκπομπές μιας ευθείας μικροταινιακής γραμμής. Έπειτα, μελετάται η κατανομή του ρεύματος στο επίπεδο αναφοράς μιας απλούστερης γεωμετρίας μαιανδρικής μικροταινιακής γραμμής και παρουσιάζονται φαινόμενα περισσότερο αισθητά σε υψηλές συχνότητες. Έπειτα, μελετώνται οι εκπομπές από μια γεωμετρία μικροταινιακής γραμμής, η οποία διασχίζει σχισμή στο επίπεδο αναφοράς. Επίσης, μελετάται η συμπεριφορά μικροταινιακής γραμμής ευρισκόμενης στο χείλος μιας πλακέτας. Επιπλέον, μελετάται ένα πρόβλημα σχεδιάσεως αποτελεσματικής ηλεκτρομαγνητικής θωρακίσεως και υπολογίζεται η αποδοτικότης της θωρακίσεως. Σε επόμενο κεφάλαιο, μελετάται η επίδραση ασυνεχειών ευρισκόμενων σε μια δομή μικροταινιακής γραμμής και σχεδιάζεται ένα μεταϋλικό, ενώ παράλληλα προσδιορίζονται χαρακτηριστικές παράμετροι της δομής. Ακολούθως, σχεδιάζονται τρία είδη δομών που περιλαμβάνουν οπές via. Αυτές είναι: μία απλή via , μια δομή διαφορικών via και μια εφαρμογή απομονώσεως δυο συζευγμένων ταινιογραμμών χρήσει ενός φράχτη από οπές via. Τέλος, προσομοιώνεται η λειτουργία μιας πραγματικής πλακέτας και υπολογίζονται οι ηλεκτρομαγνητικές της εκπομπές στο μακρινό πεδίο. Παράλληλα, παρουσιάζονται ορισμένα στατιστικά του χρόνου εκτελέσεως και των απαιτούμενων πόρων για την προσομοίωση, γίνονται σχόλια και επισημάνσεις που αφορούν στα χαρακτηριστικά των χρησιμοποιούμενων αλγορίθμων για τη διεξαγωγή μετεπεξεργασίας των δεδομένων και δίνονται χρήσιμες συμβουλές όσον αφορά σε χαρακτηριστικά του λογισμικού Προσομοιώσεως και σε δυνατότητες επιταχύνσεως της Προσομοιώσεως που προσφέρονται από το ίδιο το λογισμικό. / -

L'évolution des réseaux électriques d'une transmission de puissance unidirectionnelle classique vers un réseau diversifié avec, une grande variété de consommateurs et producteurs d'électricité, requiert le développement des technologies de mesure et de communication avancés et/ou nouvelles. Dans le cadre du projet SOGRID, une méthode innovante de mesure de courant a été développée pour enrichir la gamme existante des capteurs de courant et pour faciliter l’installation dans le réseau électrique. En effet, le capteur innovant développé ici est non seulement non-intrusif, mais peut également être déporté du câble.Dans les réseaux électriques, l'obstacle principal pour une mesure précise du courant est la nature triphasée de transmission de puissance. Un capteur de courant qui doit être utilisé dans le réseau électrique doit donc fournir une sélectivité géométrique entre les différentes phases. Les solutions commerciales existantes sont dites non-intrusives, mais nécessitent tout de même de venir entourer le conducteur d'intérêt pour mesurer le champ le long d'un chemin fermé. Ces solutions comprennent des bobines de Rogowski et les mesures en boucle fermée avec des capteurs de champs comme les magnétorésistances, les capteurs à effet Hall ou les fluxgates. Toutefois, un placement autour du conducteur limite la miniaturisation requise par le développement des réseaux intelligents : des capteurs miniatures peuvent être intégrés avec d'autres unités de mesure et de transmission de données pour permettre le suivi et le contrôle des réseaux intelligents modernes avec une maille plus dense.Afin de rependre à ces exigences, et pour améliorer la sélectivité géométrique des conducteurs, une méthode de mesure de courant basée sur la décomposition du champ en harmoniques spatiales a été développée dans cette thèse.Cette décomposition est basée sur le développement du champ magnétique à l'intérieur d'une région défini avec une série de fonctions périodiques angulaires, une loi d’évolution radiale particulière et des coefficients de développement correspondants, de sorte que la somme des ordres (théoriquement infini) de développement reconstruit le champ avec précision. Si ce développement est effectué pour une région sans sources, qui est donc entouré des sources de champ, il est défini comme une décomposition interne, qui utilise des fonctions croissantes du rayon, à partir du centre de décomposition en direction de la source de champ. Le procédé de mesure de courant est basé sur la détermination des coefficients de développement pour les différents ordres, dans lequel les ordres supérieurs présentent une dépendance réduite aux sources de perturbation (plus éloignes du conducteur d’intérêt). La relation entre ces coefficients et le courant d'intérêt est linéaire et défini par des facteurs de transfert.Afin d'exploiter la sélectivité géométrique accrue des ordres supérieurs, il est nécessaire d'effectuer un nombre suffisant de mesures du champ magnétique sur la limite d'une région appropriée afin de déduire les coefficients de développement à partir de la résolution d'un problème inverse. La taille et le positionnement de ce réseau de capteurs jouent des rôles essentiels dans la détectabilité des contributions d'ordre supérieur. Des prototypes appropriés pour une décomposition en 2D (pour les conducteurs rectilignes) et en 3D (pour les conducteurs avec des chemins arbitraires) ont été conçus, mis en œuvre et ensuite testés en laboratoire au cours de cette thèse.D'autres développements se concentrent sur la détermination des facteurs de transfert caractéristiques. En effet, tandis que ceux-ci peuvent être facilement déterminés si un courant contrôlé connu est introduit dans le conducteur, une méthode qui permet de les retrouver dans des conditions d'opération réelles doit être développée pour des applications industrielles. Afin de répondre à ce besoin, une méthode de calibration appropriée est aussi présentée dans cette thèse. / The evolution of electrical grids from conventional unidirectional power transmission to diverse networks with a large variety of electricity consumers and producers requires the development of advanced and/or novel measurement and communication technologies, in order to create smart grids. As a part of the SOGRID project, an innovative current measurement method was developed to supplement the existing range of current sensors and to facilitate the installation, since the sensor is not only non-intrusive but can also be located at a distance from the cable.The primary obstacle for precise current measurement in power grids is the three-phase nature of power transmission. A current sensor that is to be employed in the electrical grid must therefore provide geometrical selectivity between the individual phases. Existing commercial current sensors are non-intrusive but require placement around the conductor of interest, e.g. to measure the field along a closed path. Solutions include Rogowski coils, magnetoresistors, Hall effect or fluxgate sensors as well as magneto-optical solutions. However, a placement around the conductor limits the miniaturization required by smart grid development: miniature sensors can be integrated with other measurement and data transmission units, thus enabling the densely meshed monitoring and control of modern smart grids. In order to avoid these restrictions and to improve geometrical selectivity, a current measurement method based on the decomposition of the field into spatial harmonics has been developed in this thesis. The measurement principle allows for the fabrication of innovative current sensors that can be installed besides the conductor.The decomposition of the magnetic field into spatial harmonics is based on the development of the magnetic field within a defined area/volume in a series of products of periodic functions, a radial dependence and corresponding development coefficients, so that the sum of the (in theory infinite number of) development orders reconstructs the field accurately. If this development is performed for a source-free region besides the source of the field, it is defined as an internal decomposition, which uses functions that increase from the center of decomposition toward the field source. The current measurement process is based on the determination of the development coefficients for the various orders, wherein higher orders exhibit a reduced dependence on perturbing sources (as long as the field measurements are performed closer to the conductor of interest than to the perturbing conductor). The relation between these coefficients and the current of interest is linear and defined by transfer factors.In order to exploit the increased geometrical selectivity of higher orders, it is necessary to perform a sufficient number of magnetic field measurements on the boundary of a suitable area/volume in order to derive the development coefficients from the solution of an inverse problem. The size and positioning of this sensor array also plays a vital role in the detectability of higher order contributions to the field. Suitable 2D (for straight conductors) and 3D (for arbitrary conductor paths) prototypes were designed, implemented and subsequently tested in the laboratory during this thesis.Further developments focus on determining the characteristic transfer factors. While these can be easily determined if a known controlled current is induced in the conductor, a method that allows for their determination under real operating conditions must be developed for industrial applications. A suitable calibration method is presented in this thesis.

Le raccordement des systèmes PV ou des systèmes de recharge des VE au réseau peut avoir des impacts sur le fonctionnement du réseau:• Variation de tension• Déséquilibre de tension entre phases• Impact du caractère intermittent de la ressource solaire• Impact du caractère aléatoire des systèmes de recharge des VE• Injection d'harmoniques de découpage au réseau si les onduleurs ne sont pas munis de filtres efficaces• Interactions harmoniques entre onduleurs à travers le réseau• Injection de courant continu au réseau• Courants de fuite• Impact sur les pertes• Impact sur la congestion en cas de recharge des VE…C'est pourquoi, l'objectif de cette thèse est de développer les stratégies de contrôles/commandes intelligents pour les onduleurs PV et les systèmes de recharge des VE de afin de- réduire le coût total du système PV ou du système de recharge,- augmenter la performance des onduleurs PV raccordés au réseau- augmenter le taux de pénétration des systèmes PV ou de recharge des VE- assurer la continuité de service- participer au réglage de tension et de fréquence du réseau- contribuer à la stabiliser le réseau en cas nécessaire- améliorer la qualité de l'énergie- éviter les congestions…Dans le cadre du travail, la définition des services apportés par systèmes PV ou les systèmes de la recharge des VE est nécessaire. Ces services que les systèmes PV ou les systèmes de recharges qui peuvent apporter au réseau, sont élaborés dans un but prospectif : respect du plan de tension par régulation, absorption/production de puissance réactive selon le besoin, tenue aux creux de tension, amélioration de la qualité.Les études concernées :- Etude des interactions (impacts) entre les onduleurs PV et le réseau- Etude des interactions (impacts) entre les onduleurs de la recharge des VE et le réseau- Définition des services apportés par ces systèmes- Développement et modélisation d'un onduleur bidirectionnel- Développement des systèmes de contrôle/commande intelligent pour ces services:o Réglage de tension. Gestion de congestion. Amélioration de la qualité (ex : harmoniques). Capacité de tenue aux creux de tension. / The connection of PV systems or EV charging systems may impact on the operation of the electrical network:• Voltage variation• Voltage unbalance between phases• Impact of the intermittent nature of the solar resource• Impact of the random nature of EV charging systems• Harmonic injection in the network• DC injection network• Leakage currents• Impact on loss• Impact on congestion in case of EV charging ...Therefore, the objective of this thesis is to develop strategies to control / intelligent controls for PV inverters and charging systems for EVs to- Reduce the total cost of the PV system or charging system,- Increase the performance of PV inverters connected to the network- Increase the penetration of PV or EV charging- Ensure continuity of service- Participate in the regulation of grid voltage and grid frequency- Contribute to stabilize the grid- Improving the quality of energy- Avoid congestions...As part of the work, the definition of services provided by PV systems or EV charging systems is required. These services PV systems or systems that can provide to the network, are developed in a prospective: regulation of the voltage plan, absorption / reactive power as needed, withstand voltage dips, improving quality. Studies concerned:- Study of interactions (impacts) between PV inverters and network- Study of interactions (impacts) between the inverters and EV charging network- Definition of the services provided by these systems- Development and modeling of a bidirectional inverter- Development of control systems / intelligent control for these services: Voltatge controlo Management of congestiono Improved quality (eg harmonics). Ability to ride-through voltage dips.