Dissertations / Theses on the topic 'Equivalent circuit parameter'

L'etude presentee concerne la verification du schema electrique d'un circuit integre obtenu par extraction. Cette verification est basee sur la comparaison du schema electrique extrait avec le schema electrique de reference, utilise par le concepteur pour dessiner le circuit. Du point de vue mathematique, une telle comparaison est equivalente a un test d'isomorphisme effectue sur les graphes associes aux deux schemas. L'algorithme employe prend en compte tous les parametres des graphes (connectivite, type de noeuds, type de liaisons. . . ) pour determiner si oui ou non ces graphes sont isomorphes, avec une complexite abordable, ce qui permet son application a des circuits d'assez grande taille

Electrical equivalent circuit modeling of active components is one of the most important approaches for modeling high-frequency high-power devices. Amongst the most used microwave devices, AlGaN/GaN HEMTs demonstrated their superior performance, making them highly suitable for 5G, wireless and satellite communications. Despite the remarkable performance of AlGaN/GaN HEMTs, these devices reside on substrates that invoke limitations on the operating-frequency, power-efficiency, and current dispersion phenomenon. Also, there is a limitation in present parameters extraction techniques being not able to consider both the substrate effect (Silicon, Silicon Carbide, and Diamond) and the asymmetrical GaN HEMT structure. In this thesis work, a single extrinsic parameters extraction technique using a single small-signal topology takes into account both the asymmetrical GaN HEMT structure and the different substrate types with their parasitic conduction will be developed and studied for the first time. Moreover, large-signal modeling using Quasi-Physical Zone Division technique has been applied to both GaN/D and GaN/SiC to model the isothermal-trapping free drain current, and combined with a new simple technique for comparing performance between active devices in terms of current-dispersion. The models were verified by simulating the small-signal S-parameters, large-signal IV characteristics, and single-tone load-pull. High accuracy was achieved compared to the measurement data available in the technical literature and obtained from fabricated devices.

Lithium-ion batteries are complex systems and making a simulation model of them is always challenging. A method for producing an accurate model with high capabilities for predicting the behavior of the battery in a time and cost efficient way is desired in this field of work. The aim of this thesis has been to develop a method to be close to the desired method as much as possible, especially in two important aspects, time and cost. The method which is the goal of this thesis should fulfill the below five requirements: 1. Able to produce a generic battery model for different types of lithium-ion batteries 2. No or low cost for the development of the model 3. A time span around one week for obtaining the model 4. Able to predict the most aspects of the battery’s behavior like the voltage, SOC, temperature and, preferably, simulate the degradation effects, safety and thermal aspects 5. Accuracy with less than 15% error The start point of this thesis was the study of current methods for cell modeling. Based on their approach, they are divided into three categories, abstract, black box and white box methods. Each of these methods has its own advantages and disadvantages, but none of them are able to fulfill the above requirements. This thesis presents a method, called “gray box”, which is, partially, a mix of the black and white boxes’ concepts. The gray box method uses values for model’s parameters from different sources. Firstly, some chemical/physical measurements like in the case of the white box method, secondly, some of the physical tests/experiments used in the case of the black box method and thirdly, information provided by cell datasheets, books, papers, journals and scientific databases. As practical part of this thesis, a prismatic cell, EIG C20 with 20Ah capacity was selected as the sample cell and its electrochemical model was produced with the proposed method. Some of the model’s parameters are measured and some others are estimated. Also, the abilities of AutoLion, a specialized software for lithium-ion battery modeling were used to accelerate the modeling process. Finally, the physical tests were used as part of the references for calculating the accuracy of the produced model. The results show that the gray box method can produce a model with nearly no cost, in less than one week and with error around 30% for the HPPC tests and, less than this, for the OCV and voltage tests. The proposed method could, largely, fulfill the five mentioned requirements. These results were achieved even without using any physical tests/experimental data for tuning the parameters, which is expected to reduce the error considerably. These are promising results for the idea of the gray box which is in its nascent stages and needs time to develop and be useful for commercial purposes.

Electric power systems have been in existence for over a century. Electric power transmission line systems play an important role in carrying electrical power to customers everywhere. The number of transmission lines in power systems is increasing as global demand for power has increased. Parallel transmission lines are widely used in the modern transmission system for higher reliability. The parallel lines method has economic and environmental advantages over single circuit. A fault that occurs on a power transmission line will cause long outage time if the fault location is not located as quickly as possible. The faster the fault location is found, the sooner the system can be restored and outage time can be reduced. The main focus of this research is to develop a new accurate fault location algorithm for parallel transmission lines to identify the fault location for long double-circuit transmission lines, taking into consideration mutual coupling impedance, mutual coupling admittance, and shunt capacitance of the line. In this research, the equivalent PI circuit based on a distributed parameter line model for positive, negative, and zero sequence networks have been constructed for system analysis during the fault. The new method uses only the voltage and current from one end of parallel lines to calculate the fault distance. This research approaches the problem by derivation all equations from positive sequence, negative sequence, and zero sequence network by using KVL and KCL. Then, the fault location is obtained by solving these equations. EMTP has been utilized to generate fault cases under various fault conditions with different fault locations, fault types and fault resistances. Then the algorithm is evaluated using the simulated data. The results have shown that the developed algorithm can achieve highly accurate estimates and is promising for practical applications.

Les applications de l’électronique de puissance contribuent à la pollution harmonique des réseaux électriques. Pour estimer le niveau de distorsion de tension, les différents composants du réseau doivent être modélisés en régime harmonique, en particulier les charges consommatrices, industrielles, commerciales et domestiques. L’étude concerne la modélisation de l’impédance harmonique des charges qui peuvent être séparées en deux grandes catégories: les charges passives et les charges dites actives qui réalisent une conversion d’énergie électromécanique. Les modèles disponibles pour les charges élémentaires sont récapitules en termes de complexité et de précision. Puis une méthode d’agrégation est développée, permettant d'obtenir un circuit équivalent d'ordre minimal et de structure compatible avec celle du réseau. La méthode d'identification des paramètres de ce circuit est basée sur une représentation fréquentielle de l’impédance harmonique, afin d'obtenir une réponse qui coïncide avec celle du réseau réel. Ce modèle agrège est utilise pour étudier la sensibilité de l’impédance harmonique aux variations aléatoires des paramètres caractéristiques du réseau et des charges.

2012 - 2013
Proton Exchange Membrane, also named Polymer Electrolyte Membrane fuel cells (PEMFC) are interesting devices for energy conversion. Their development is due to the high efficiency, acceptable power density, quick start-up and good environmental compatibility. On the other hand, reliability cost and durability are the main challenges for PEM fuel cell commercialization. In 2010 the American Department of Energy (DoE) sets a target of 40000 hours for stationary and 5000 hours for automotive applications, respectively. Actually, these standards are considered as the mainly reference in fuel cell research. Based on electro-catalytic reactions, the PEMFC operation is influenced by system functioning conditions. In case of system operation in abnormal conditions several chemical, mechanical and thermal degradation mechanisms could take place inside the cell. Among other, improper water, thermal and gas managements can introduce a cell voltage drop, thus reducing the system performance. A long-term exposure to these phenomena causes the PEMFC lifetime reduction. Thus, a good system management is one of the primary targets to ensure suitable PEMFC durability. For this purpose, research activities are oriented towards the development of newest advanced monitoring and diagnostic algorithms. The primary goal is monitoring the system operation ensuring a correct system control. Moreover, the diagnostic tool (i.e. both algorithm and sensors) allows the detection of system component malfunctioning; it can isolate one or more faults that may have occurred causing the abnormal behaviour of the system operation...[edited by author]
XII n.s.

This doctoral thesis is dedicated to the modeling and analysis of high-power multiphase electric machines. In the first part, the multiphase technology and variety in the field of high power electric drives and power generation is illustrated by means of some significant industrial realizations which highlight the main design issues and advantages that may lead to choose a high number of phases in large electric machinery. Subsequently, the attention is focused on the so called split-phase configurations, characterized by stator windings split into *N* three-phase sections. The modeling of these machines is revisited from an analytical viewpoint and an equivalent circuit representation is proposed for them; in particular, it is shown and experimentally proved that, when the number of stator sections *N* exceeds two, a magnetic cross-coupling arises between d-axis and q-axis equivalent circuits. A different modeling technique, called Vector-Space Decomposition (VSD), is then considered and extended to any kind of multiphase configuration, whether symmetrical or asymmetrical, through suitable geometrical transformations. A special effort is particularly spent on setting forth a general methodology which allows for space harmonics (related to the non-idealities of air-gap shape and winding distribution) to be included in the machine model through VSD. The result achieved is that some geometry- or design-related machine information which usually require finite-element simulations to be caught, can be successfully incorporated in the VSD lumped-parameter model of the *n*-phase machine, to an extent that is larger and larger as *n* grows. As an application example, it is shown how space harmonic effects in the operation of a six-phase and a nine-phase salient-pole multiphase machines can be reproduced by time-stepping finite-element analysis and by the proposed lumped-parameter methodology with the same level of accuracy but with a significant time and computational saving in the last mentioned case. A part of the thesis is also dedicated to model parameter calculation. Addressing the case of a general number and distribution of stator phases, algorithms are proposed to compute magnetizing parameters through the winding function theory and analytical computation methods are proposed for self and mutual leakage inductance parameters. The accuracy of the proposed computation method is assessed by comparison with measurements or real machines. The final part of the thesis is devoted to the study of two detailed phenomena which characterize high-power multiphase machines when supplied by multiple inverters. In the instance of multiple current-source inverters, a model is proposed and validated to describe commutation transients including the mutual interaction effects between different winding sections. In the instance of multiple voltage-source inverters, the low-frequency current circulation phenomenon is investigated analytically and experimentally showing how it arises due to the internal non-ideal machine structure.
Questa tesi di dottorato tratta della modellizzazione ed analisi di machine multiphase di alta potenza. Nella prima parte, si illustra la tecnologia multifase e la varietà delle sue forme progettuali nel campo degli azionamenti elettrici e della generazione di energia elettrica. Nella descrizione, si fa riferimento ad alcune realizzazione industriali significative che mettono in luce le principali problematiche e vantaggi che possono indurre alla scelta di una configurazione multifase in macchie elettriche di grossa taglia. Successivamente, viene trattata una particolare configurazione multifase detta “split-phase”, propria di quelle macchine il cui avvolgimento statorico è suddiviso in *N *sezioni multifase. La modellizzazione di queste macchine è rivisitata da un punto di vista analitico e ne viene fornita una rappresentazione in termini di circuito equivalente; in particolare, si dimostra teoricamente e sperimentalmente che, quando il numero *N* di sezioni statoriche è maggiore di due, si verifica un accoppiamento magnetico tra i circuiti equivalenti di asse diretto e di asse in quadratura. Successivamente, si considera una diversa tecnica di modellizzazione, chiamata Vector-Space Decomposition (VSD), con l’intento di darne una formulazione estesa che si applica trattare ogni tipo di configurazione multifase, sia simmetrica che non, ricorrendo ad opportune trasformazioni geometriche. Particolare attenzione è dedicata alla formulazione di un metodo generale che consente l’inclusione, nel modello della macchina con tecnica VSD, delle armoniche spaziali dovute alla non-idealità della geometria del traferro e della distribuzione degli avvolgimenti. In risultato che ne consegue è la possibilità di incorporare nel modello a parametri concentrati della macchina *n*-fase, realizzato con metodo VSD, alcune informazioni, legate alla geometria e al progetto di dettaglio della macchina, le quali normalmente possono essere tenute in considerazione mediante approcci di simulazione agli elementi finiti. La quantità di informazioni includibile nel modello a parametri concentrati secondo la tecnica proposta si mostra essere tanto maggiore quanto più grande è il numero di fasi *n*. Come esempio di applicazione, si mostra come gli effetti legati alle armoniche spaziali nel funzionamento di una macchina a poli salienti a 6 fasi e a 9 fasi possano essere riprodotti, mediante analisi agli elementi finiti nel dominio del tempo e mediante il metodo a parametri concentrati proposto, con lo stesso livello di accuratezza ma con un significativo risparmio di tempo e di risorse computazionali in quest’ultimo caso. Una parte della tesi è altresì dedicata al calcolo parametrico dei modelli. Riferendosi al caso di numero e distribuzione generici delle fasi di statore, vengono proposti algoritmi di calcolo dei parametri di magnetizzazione basati sulla teoria basata sulle “winding functions” e metodi di calcolo analitici per i parametri di auto e mutua induttanza dispersa. L’accuratezza dei metodi di calcolo proposti è verificata per confronto con misure su macchine reali. La parte finale della tesi è dedicata allo studio di due fenomeni dettagliati che caratterizzando le macchine elettriche multifase alimentate da più invertitori. Con riferimento all’alimentazione da più invertitori a corrente impressa, viene proposto e validato un modello che descrive i transitori di commutazione tenendo conto degli effetti di mutua interazione tra diverse sezioni dell’avvolgimento. Nel caso di alimentazione da più invertitori a tensione impressa, viene indagato analiticamente e sperimentalmente il fenomeno di correnti armoniche di ricircolo tra le fasi a bassa frequenza, dimostrando come esso si verifichi a causa della struttura interna non-ideale della macchina.

The presented thesis focused on the study of effect of temperature and different loading condition of an inductive current transformer for medium voltage purposes. Equivalent circuit parameters behavior of the current transformer is analyzed for two different temperatures 24°C and 60°C and varying working conditions (current and voltage). Application of Short Circuit and Open circuit test is done for the current transformer under test with varying loading conditions and two temperatures of interest. Interesting behavior of the shunt parameters of the current transformers are of most attention and can be implemented during modeling a current transformer.

Práce se zabývá studiem superkondenzátorů (SC). Výstupem je detailní studie principů přenosu náboje ve struktuře SC, ukládání energie a nový náhradní model SC, který je založen na fyzikálních zákonitostech a principech SC. Dále byl vytvořen matematický model SC, který popisuje chování náboje v jeho aktivní vrstvě. SC byly testovány metodami umělého stárnutí. Závislosti poklesu parametrů SC vlivem různých metodik stárnutí jsou v práci shrnuty.

Un dels problemes més importants en la Compatibilitat Electromagnètica és el control de les interferències emeses i/o rebudes per un equip electrònic a través dels seus terminals d'alimentació monofàsica. Aquestes interferències es classifiquen en mode comú i mode diferencial. La manera més usual de mitigar-les és mitjançant la utilització de filtres de xarxa. Els mètodes actuals de disseny de filtres de xarxa tracten la mitigació d'aquest tipus d'interferències per separat: no tenen en compte que ambdós tipus de senyals (mode comú i diferencial) interaccionen entre sí i es transfereixen energia en qualsevol tipus d'asimetria originada pels equips electrònics o pels mateixos filtres. Aquest fet produeix freqüentment situacions inesperades: inefectivitat dels filtres de xarxa, aparició d'interferències en mode comú o diferencial inexplicables per la topologia dels circuits, selectivitat en freqüència del filtratge de les interferències, processos de radiació, etc. Aquest tipus de situacions poden ser analitzades i corregides a partir d'un anàlisi multimodal, que tingui en compte simultàniament el mode comú i el diferencial, i la seva interacció. El treball exposat aquí pretén:
- Desenvolupar sistemes de mesura multimodal per a equips electrònics i filtres de xarxa. Aquests sistemes han de tenir en compte tant el mode comú, com el diferencial, com la seva interacció, i han de millorar les prestacions dels sistemes de mesura normatius actuals.
- Trobar models equivalents des d'un punt de vista multimodal (tenint en compte simultàniament el mode comú, el diferencial i la seva interacció) tant d'equips electrònics com de filtres de xarxa.
- Desenvolupar una metodologia de predicció de les interferències conduïdes que l'equip electrònic subministra a la xarxa elèctrica a través del filtre de xarxa al qual es troba connectat a partir dels models multimodals equivalents proposats per a ambdós dispositius.
PARAULES CLAU: Compatibilitat electromagnètica, filtre de xarxa, equip electrònic, circuit equivalent, emissió conduïda, mode comú, mode diferencial, impedància d'entrada, paràmetres S.
Uno de los problemas más importantes en Compatibilidad Electromagnética es el control de las interferencias emitidas y/o recibidas por un equipo electrónico a través de sus terminales de alimentación monofásica. Estas interferencias se clasifican en modo común y modo diferencial. La manera más usual de mitigarlas es mediante el empleo de filtros de red. Los métodos actuales de diseño de filtros de red abordan la mitigación de este tipo de interferencias por separado: no tienen en cuenta que ambos tipos de señales (modo común y diferencial) interaccionan entre sí y se transfieren energía en cualquier tipo de asimetría originada por los equipos electrónicos o por los mismos filtros. Este hecho produce frecuentemente situaciones inesperadas: inefectividad de los filtros de red, aparición de interferencias en modo común o diferencial inexplicables por la topología de los circuitos, selectividad en frecuencia del filtrado de las interferencias, procesos de radiación, etc. Este tipo de situaciones pueden ser analizadas y corregidas a partir de un análisis multimodal, que tenga en cuenta simultáneamente el modo común y el diferencial, y su interacción. El trabajo aquí expuesto pretende:
- Desarrollar sistemas de medida multimodal para equipos electrónicos y filtros de red. Dichos sistemas deben tener en cuenta tanto el modo común, como el diferencial, como su interacción, y deben mejorar las prestaciones de los sistemas de medida normativos actuales.
- Hallar modelos equivalentes desde un punto de vista multimodal (teniendo en cuenta simultáneamente el modo común, el diferencial y su interacción) tanto de equipos electrónicos como de filtros de red.
- Desarrollar una metodología de predicción de las interferencias conducidas que el equipo electrónico suministra a la red eléctrica a través del filtro de red al cual está conectado a partir de los modelos multimodales equivalentes propuestos para ambos dispositivos.
PALABRAS CLAVE: Compatibilidad electromagnética, filtro de red, equipo electrónico, circuito equivalente, emisión conducida, modo común, modo diferencial, impedancia de entrada, parámetros S.
One of the most important problems in EMC is the control of the common and differential mode interferences emitted or received by an electronic device through its single phase power-line cable. These interferences are mitigated using power-line filters. The present power-line filter methodologies treat separately the mitigation of this kind of interferences: they do not take into account that both modes interact and exchange energy at any kind of asymmetry originated by the devices connected to the power-line, or by the power-line filters themselves. This fact leads to unexpected situations: power-line filter infectivity, appearance of common and differential mode interferences not accountable by the circuit topology, frequency selectivity of the interferences, radiation processes, etc. This kind of situations can be analyzed and corrected using multimodal analysis, which takes into account at the same time the common mode, the differential mode and their interaction. This project aims to:
- Develop accurate multimodal measurement systems for both electronic devices and power-line network filters. They have to consider the common and differential modes, and their interaction, and have to improve the features of present normative measurement systems.
- Derive equivalent models from a multimodal point of view (taking into account simultaneously the common mode, the differential mode and their interaction) for both electronic devices and power-line filters.
- Develop a methodology for predicting the level of conducted emissions that an electronic device supplies to the power-line network through the power-line filter to which it is connected, using the equivalent multimodal models proposed for both devices.
KEYWORDS: Electromagnetic compatibility, power-line filter, electronic device, equivalent circuit, conducted emissions, common mode, differential mode, input impedance, S parameters.

The master’s thesis deals with the piezoelectric coefficients, the resonance frequency and especially the piezoelectric constants verification. With the assistance of several devices, for instance LCR-meter HIOKI 3532, impedance analyzer Agilent 4294A and LCR-meter Agilent E4980A, the resonance and the anti-resonance frequencies as well as impedance and capacitance of samples are measured. The paper opens with the theory of the piezoelectric phenomenon and the difference between direct and indirect piezoelectric phenomenon, it also describes the basic behaviour of a piezoelectric ceramic element during mechanical straining or applied voltage. Further, the paper concerns the description of various piezoelectric constants and their calculations. Subsequent part of the paper is devoted to the temperature dependence of the main piezoelectric parameters of PZT ceramics. The materials coefficients are delineated as a function of temperature of the piezoelectric charge coefficients dij, relative permittivity r, electromechanical coupling factor kij and frequency constants Ni. One of the chapters also determines the piezoelectric charge constant d33 of PZT ceramics by laser interferometer and compares it with the value measured by resonance methods. The surface displacement was measured by a single-beam interferometer Polytec OFV-5000. The results of measurements of piezoelectric charge coefficients d33 acquired by the first and the second method are identical. The last section of the paper is focused on different methods of experimental studies on the characteristics of heat transfer by diffusing heat through conduction between the silver-plated surface of cylinder made of PZT ceramics. The effect on the resonance and the anti-resonance frequencies is monitored. There after, the real heat, determined by thermo camera and the physical model of heat transfer created in program COMSOL Multiphysics, is analysed.

Les réseaux d’antennes planaires sont réputés par leur grande directivité et leur facilité de mise en œuvre qui offre la possibilité d’avoir un diagramme de rayonnement commandable. Cependant l’étude globale tenant compte des différents couplages EM par une théorie électromagnétique rigoureuse nécessite un espace mémoire important et un temps de calcul considérable. Pour surmonter à ces inconvénients, nous proposons d’introduire une nouvelle approche théorique basée sur le théorème de Floquet permettant la réduction du volume d’analyse EM au niveau d’une seule cellule élémentaire. Nous allons focaliser notre étude à la détermination des termes de couplage dans une configuration répartie dans une trame presque-périodique et en particulier pour les réseaux d’antennes périodiques et quasi-périodiques alimentés par des sources arbitraires. Dans ce cas, nous utiliserons les décompositions en modes de Floquet (adaptées aux structures périodiques) pour extraire la matrice de couplage [S]. Ces décompositions sont des concepts établis de longue date et a priori démontrés par de supports théoriques solides. Par conséquent, cette analyse modale permet de simplifier la résolution du problème considéré surtout quand les éléments rayonnants sont fortement couplés. Une seule méthode numérique est adoptée afin de modéliser la structure proposée : la méthode des moments combinée avec le circuit équivalent généralisé : MoM-GEC. La validation de cette dernière sera réalisée par comparaison avec d’autres méthodes numériques exactes
Planar antenna arrays are renowned for their high directivity and ease of implementation, which offers the possibility of having a controllable radiation pattern. However the global study taking into account the different EM couplings by a rigorous electromagnetic theory requires a large memory space and a considerable computation time. To overcome these drawbacks, we propose to introduce a new theoretical approach based on the Floquet theorem allowing the reduction of the EM analysis volume at the level of a single elementary cell (basic cell). We will focus our study on the determination of coupling terms in a distributed configuration in an almost-periodic frame and in particular for periodic and quasi-periodic antenna arrays fed by arbitrary sources. In this case, we will use Floquet mode decompositions (adapted to periodic structures) to extract the coupling matrix [S]. These decompositions are concepts established for a long time and a priori demonstrated by solid theoretical supports. Consequently, this modal analysis makes it possible to simplify considerably the resolution of the problem, especially when the radiating elements are strongly coupled. A single numerical method is adopted in order to model the proposed structure: the method of moments combined with the generalized equivalent circuit: MoM-GEC. Validation of the latter will be done by comparison with other exact numerical methods

碩士
國立中山大學
電機工程學系研究所
104
A half-bridge series resonant inverter is implemented to recognize the parameters of the equivalent circuit model of an induction coil loaded with steel pots for induction cookers. When a steel pot is loaded on the induction coil, the circuit parameters and thus the resonant frequency vary with the shape and material of the pot. The effects of the inverter switching frequency and the position between the pot and the induction coil are analyzed from experimental tests with seven pots of different shapes and materials. Accordingly, the parameters of the equivalent circuit can be expressed as equations with functions of the switching frequency. The derived circuit model can be used for determining the operating ranges of the output power and the switching frequency of the resonant inverter loaded by specified pots with similar operating characteristics. The parameter derivation method to two exemplar design cases of 2.5-kW and 3.3-kW inductor cookers has been validated by experimental tests.

碩士
國立交通大學
電子工程系所
97
Small signal equivalent circuit models and the corresponding parameter extraction methods have been developed in this thesis for RF CMOS circuit simulation. Both two-port 3-terminal (3T) and four-port 4-terminal (4T) RF MOSFETs are covered in this work. The former one – 3T MOSFETs with a common source topology is a conventional one widely used in RF circuits, and the test-key layout is arranged in a two-port configuration with a common ground for source and body tied together to fit the two-port RF measurement system. In fact, source and body terminals are not always connected together in the practice of RF circuit design, the traditional two-port test-key cannot capture a whole spectrum of 4T MOSFET’s features and cannot adequately represent 4T MOSFET’s characteristics over high frequencies. To solve this critical problem, the latter one – four-port 4T RF MOSFETs are designed and fabricated in 0.13um RF CMOS process for high frequency characterization and model development in this work. In this thesis, the basic principles of two-port and multi-port scattering parameters (S-parameters) will be reviewed in the first place. Then, the small signal equivalent circuits and parameter extraction methods developed for two-port 3T device under various biases and geometries will be discussed in detail. Based on what have been done for two-port 3T MOSFET, a modified equivalent circuit relevant to four-port 4T test structures, and the corresponding fundamental works, such as de-embedding method and parameter extraction flow have been carried out. Finally, an extensive verification has been performed on the proposed small signal equivalent circuit models through simulation under various biases. The model accuracy is certified over a broad frequency up to 40GHz and various bias conditions – linear and saturation. More importantly, the model parameters of the developed equivalent circuit models manifest themselves a promisingly good scalability over various geometries in MOSFETs, such as gate lengths and gate finger numbers under a specified finger width. The accuracy over frequencies and biases and scalability over device geometries is useful to improve accuracy of high frequency circuit simulation and facilitate RF CMOS integrated circuit development.

碩士
國立中山大學
電機工程學系研究所
104
For a photovoltaic (PV) panel, an equivalent circuit with an additional parasitic capacitance on the conventionally used single-diode static model can be used to interpret the phase deviation between the output voltage and current and to simulate the dynamic characteristics. The parameters of the equivalent circuit can be derived simply from five test points when a boost converter is attached to the PV panel for maximum power point tracking (MPPT) drawing a rippled current. The circuit parameters of the static model are calculated from the open-circuit voltage, the maximum power, and the short-circuit current, which can be rapidly obtained by operating the boost converter at a designated ripple current. An equation to account for the variation of the parasitic capacitance can be derived from two arbitrary operation points with voltages less than the diode threshold voltage of the PV panel. The circuit parameters for different irradiations can be obtained from the ratio of the short circuit current to the pre-known short-circuit current. Experimental results have confirmed that fitness of the equivalent circuit model with parameter identification and demonstrated that it can be used for simulating the transient behaviors of a PV panel with a rippled current.

碩士
國立雲林科技大學
營建工程系碩士班
93
Based on the concept for approximating the dynamic flexibility function of foundation by polynomial-fraction, different mathematical methods have been developed in recent studies to decompose this polynomial-fraction and then directly correspond it to various types of systematic lumped-parameter models for representing the dynamic behavior of unbounded soil. Other than being applied for the simplification in analysis and design, these systematic lumped-parameter models can be also correlated to equivalent electric circuits due to their concise mathematical formulation and simple physical correspondence. Therefore, these models further lead to great potentials in efficiently simulating soil-structure interaction (SSI) effects in the laboratory. This research is consequently focused on the exploration of employing a simple equivalent electric circuit to simulate the lumped-parameter model and hopefully will provide clear directions for future studies in representing a total SSI system with the experiment of electric circuits. After establishing the extensive similarity between the basic mechanical elements in a lumped-parameter model and the fundamental electronic elements in an electric circuit, the effectiveness of using an equivalent electric circuit to simulate the dynamic behavior of soil system is first verified in this study with the application of circuit simulation software. Even though there theoretically exist two alternatives in corresponding to the input force with either the electric current or voltage, this study only adopts the correspondence of the electric voltage to the input force in conducting the electric circuit simulations and experiments since it is relatively convenient to control the input voltage in an electric circuit. According to the investigation on different vibration directions of an embedded square foundation system, the experimental results for the equivalent electric circuits generally agree well with the analytical results for the corresponding lumped-parameter models except for certain minor high-frequency noises from the measurements of electric current. With comparing the results for inputting different earthquake motions, it can also be observed that the circuit experiment errors in the cases of low-frequency earthquakes are noticeably larger than those in the cases of high-frequency earthquakes. Moreover, the approximation with the equivalent circuit in the cases of rocking and torsional vibrations of foundation is deteriorated, compared to the cases of horizontal and vertical vibrations. In summary, the experimental results demonstrate that the simulation of a lumped-parameter model with a simple equivalent electric circuit is essentially effective and successful considering the limitations from experiment equipments. It is expected that the research scope and application possibility of the equivalent electric circuit can be significantly extended if the limitations coming from experiment equipments can be overtaken in the future.

碩士
國立雲林科技大學
營建工程系碩士班
92
Based on the approximation by polynomial-fraction, different mathematical methods are applied in this study to investigate its various possible decompositions. These decompositions are further categorized to develop various types of systematic lumped-parameter models for efficiently representing the dynamic behavior of unbounded soil. Following the concise formulation employing a ratio of two polynomials to represent the normalized dynamic flexibility function of foundation and then solving the optimal coefficients of the polynomials, this research starts with two mathematical decomposition methods. The first method deduces three different decompositions according to nested division and also defines the transformation between the high-order type and low-order type of polynomial-fraction. Subsequently, systematic nested decomposition can be performed on the original polynomial-fraction representing the normalized dynamic stiffness function. The second method is to decompose the polynomial-fraction into the summation of numerous first-order and second-order partial fractions with real coefficients via partial-fraction expansion. This method can be corresponded to an “in-series” type and another “in-parallel” type of physical arrangement based on the high-order type of polynomial-fraction in flexibility formulation and the low-order type of polynomial-fraction in stiffness formulation. Moreover, applying the nested division decomposition, each decomposed second-order partial fraction can also be corresponded to three different discrete-element models. Finally, with the combination of the above two types of polynomial-fraction decomposition, four alternative decomposition options can be obtained in each round of decomposition operation and various systematic lumped-parameter models can be consequently constructed. Furthermore, another major phase of this study is to explore the possibility of using equivalent electric circuits to simulate systematic lumped-parameter models. With the mathematical correspondence between certain electronic elements and mechanical elements, this research develops two types of electric circuit systems to simulate the dynamic system represented by a lumped-parameter model. Applying the electric circuit simulation software OrCAD PSpice A/D, this part of preliminary investigation sufficiently verifies the feasibility and accuracy in utilizing electric circuit simulations to study the foundation vibration problems.

碩士
國立交通大學
電子工程系所
94
Parameter extraction method development is very important for accuracy of simulation. In the past, foundries always provide customers with the 3T sample layout, whose source and body terminals are connected together. But foundries tend to provide customers with 4T sample layout for circuit designers’ purpose at present. And model card is constructed on 4T device to match the practical using way of circuit designers. In order to provide circuit designers with accurate model card, reliable parameter extraction method development is obviously important. 3T and 4T device in the thesis are put in 2-port pad to do RF measurement and parameters extraction. In this thesis, 2-port de-embedding and parameters extraction methods have been discussed in detail and used extracted parameters to verify the reliability and accuracy of small signal equivalent model. Obtaining correct small signal equivalent model represents that we can extract correct parameter values which could provide us with direction and thought to construct better model card. The last part of this thesis is detailed discussion of parasitic capacitances. The results reveal that the simulation and analytical calculated are very matched. This represents the thought applied to calculating process is very correct. The success of analytical calculated model can accurately estimate the parasitic capacitances of specific structure. It is worthy to mention that the calculating method is more direct and simpler than other published references.

碩士
雲林科技大學
電機工程系碩士班
96
This thesis presents a measurement technique for the analysis of the equivalent circuit parameters of solar cells and modules, including the presentation of the measurement system. Several I-V characteristic curves of solar cells and modules were obtained from measurement. The proposed methods include the straightforward calculation and least-squares to calculate the five parameters of the circuit model, allowing the I-V characteristic curves of solar cells and modules to be drawn by bring those parameters into I-V characteristic equation. Comparison between calculated and measured results have been carried out to test the accuracy and reliability of the two methods. Finally, application of this measuring method and calculation method to analysis the partial shading fault of PV system is also presented.

碩士
雲林科技大學
光學電子工程研究所
96
This thesis summarizes extraction of DC parameters and thermal parameters in VBIC equivalent circuit model for In0.4Ga0.6As0.8Sb0.2 hetero-junction bipolar transistors. Both critical and negligible parameters are pointed out in order to obtain an accurate model. To reduce the time spent in measurement and extract parameters efficiently, the extraction focuses on forward mode operation and neglects reverse mode operation. Parameters for reverse operation are used to optimize the collector current versus collector-emitter voltage (IC-VCE) output characteristic. In the forward Gummel plot, ideal current region is essential for initial parameters extraction, and high current region is important for obtaining a satisfying result in the IC-VCE output characteristic. Early effect, self-heating effect, and avalanche breakdown effect are considered in the IC-VCE output characteristic. This extraction procedure is efficient and the VBIC model parameters are validated by ADS simulation.

碩士
國立中山大學
電機工程學系研究所
97
Characteristics of small signal components for circuit designers are very important in circuit design. Many researchers have been working hard on removing the unwanted parasitic effects which is used to get the intrinsic characteristics of the small signal parameters. In this thesis, we propose a novel four-port de-embedding procedure which based on two-port cascade structure de-embedding procedure and combined with metal and polysilicon ground-shielded technology, and let four terminals of MOSFET are connected individually to four signal pads. With such de-embedding procedure, the intrinsic and substrate element values of small-signal model are extracted by different bias.

碩士
國立成功大學
系統及船舶機電工程學系
106
This thesis describes a table-based derivation of first-order RC equivalent circuit parameters for a Lithium-ion battery circuit in order to estimate the cell voltage of a battery under different charging currents. The first-order RC equivalent circuit of a battery consisted of one voltage source, one resistance and one resistor-capacitor circuit was able to account for the charging dynamics observed in the experiment. Two sets of parameters for a battery tested at room temperature were derived from two different pulse voltage curves. One was under 1.176 A pulse charging current, and the other was under 0.84 A pulse charging current. Then, the equivalent circuit parameters were used to estimate the cell voltage of a battery with a four-stage constant current (4SCC) charging method. The mean absolute percentage error (MAPE) between the measured and estimated cell voltages of batteries charged with the 4SCC charging method were calculated to be 0.55 % and 0.28 %, respectively. The overall seems to be very accurate, but the maximum relative error is as high as 3 %. It is not accurate, especially for balancing circuit design or charging method based on voltage. Since the charge current of the 4SCC charging method varies in different stages, using a set of the individual parameters to simulate the cell voltage of a battery charged with the 4SCC charging method is not accurate due to different SOCs (State of Charges) stored at various stages. To solve such problem, this study proposes to use a look-up table approach to mitigate the MAPE of the measured and estimated cell voltage of a battery charged with the 4SCC charging method. The MAPE is reduced to be 0.2 %.

Dissertação de Mestrado Integrado em Engenharia Electrotécnica e de Computadores apresentada à Faculdade de Ciências e Tecnologia
Os objetivos principais desta dissertação são, de uma forma geral, comparar as alterações dos parâmetros do circuito equivalente por fase de quatro motores de indução trifásico com rotor em gaiola de esquilo de classes de rendimento IE1, IE2, IE4 de um único fabricante, correlacionando-os com as perdas que os mesmos produzem e com aspetos construtivos dos motores em termos dimensionais e de quantidade e qualidade dos materiais ativos utilizados. Serão desenvolvidos modelos de simulação para os diferentes motores analisados, com bases em ensaios experimentais.Este documento está estruturado da seguinte forma:O capítulo 1 exibe o enquadramento do tema sobre o qual se desenvolveu esta dissertação.No capítulo 2 são apresentados os conceitos gerais relacionados com o motor de indução trifásico com rotor em gaiola de esquilo. Inicialmente é abordado o princípio de funcionamento do motor e são relatados os principais aspetos construtivos do mesmo. De seguida é fundamentado a obtenção do circuito equivalente por fase do motor com representação dos parâmetros do mesmo. São também definidas as perdas elétricas e mecânicas que ocorrem no motor de indução e por último, é feita uma comparação das duas principais normas usadas para o cálculo do rendimento dos motores.No capítulo 3 é feita uma descrição das montagens experimentais, equipamentos e procedimentos utilizados na realização das medições. De seguida são abordados dois métodos de cálculo dos parâmetros do esquema equivalente, sendo um pela análise do circuito e outro seguindo o procedimento aconselhado pela norma IEEE 112, com respetiva análise de resultados. Posteriormente é fundamentado o cálculo dos valores de rendimento obtidos, comparando as normas IEEE 112 e IEC 60034-2-1, com respetiva análise. Para finalizar serão mostrados os resultados obtidos das simulações realizadas.Finalmente, o capítulo 4 expõe as principais conclusões retiradas do trabalho desenvolvido e propõe algumas sugestões para trabalho futuro. ___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________
In this dissertation, the main parameter changes of IE1, IE2, IE3 and IE4 class induction motors, from one single supplier, are to be compared and correlated with the power losses produced and respective constructive differences in terms of dimension and active materials quantity and quality. On the basis of the experimental tests, simulation models for the different analyzed motors will be developed.This document has the following structure:Chapter 1 explains the framing of the theme of this thesis.In chapter 2, general concepts related with squirrel cage induction motors are presented.Initialy, is explained the working principle of the induction motor and the constructional features of this kind of motor are shown. Next, the equivalent circuit of induction motor is substantiated, with electric parameters represented. The electrical and mechanical losses are described and explained, and finally a comparison between the two main standards for electric machinery efficiency determination are made.In chapter 3, are described the experimental setups, equipment and procedures usedwhen carrying out the measurements. Then, two calculation methods of equivalent circuit parameters are explained and compared with appropriate analysis of the results. Posteriorly, the efficiency calculation values are shown with a comparison between standars IEEE 112 and IEC 60034-2-1, and finally, a critical analisys based on computation simulation results are made,Chapter 5 presents the main conclusions from the work developed and some suggestionsfor future work._______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________