• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 2
  • 1
  • 1
  • 1
  • Tagged with
  • 10
  • 10
  • 4
  • 3
  • 3
  • 3
  • 3
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Development of a Variable Output Power, High Efficiency Programmable Telemetry Transmitter Using GaN Amplifier Technology

Oder, Stephen, Arinello, Paula, Caron, Peter, Crawford, Scott, McGoldrick, Stephen, Bajgot, Douglas 10 1900 (has links)
Cobham Electronic Systems, Inc. has developed a field-programmable telemetry transmitter module for higher-power (0.1W to 25W) airborne telemetry applications. A key feature of the transmitter is high DC to RF conversion efficiency over the entire variable output power range of 25dB through the use of GaN amplifiers. This high efficiency is realized by using a variable voltage DC-DC converter and dynamic bias control of the GaN amplifier elements. This feature is useful in that output power can be tailored to mission requirements and timelines, thereby extending battery life and increasing operation time. The transmitter receives configuration commands and can be programmed through an external data port. The transmitter can be configured for RF power and frequency over the telemetry S-Band frequency range, and has multiple data rates. The unit consists of RF, digital and power supply circuits. The RF transmitter is a PCM-FM type with a phase-locked loop, driver amplifiers, a power amplifier and a digital processor for RF control. The unit contains a digital processor, FPGA's, and flash memory. The power supplies contains all the regulator circuits to supply power to the rest of the unit, variable output drain voltage to the GaN devices, EMI filtering, under/overvoltage protection, a temperature sensor and a digital processor for power control. The electronics are housed in a compact aluminum housing.
2

THE DESIGN OF A SINGLE CARD TELEMETRY MODULE FOR SMART MUNITION TESTING

Oder, Stephen, Dearstine, Christina, Webb, Amy, Muir, John, Bahl, Inder, Burke, Larry, Stone, Weyant 10 1900 (has links)
International Telemetering Conference Proceedings / October 18-21, 2004 / Town & Country Resort, San Diego, California / M/A-COM, Inc. has developed a miniature Tactical Telemetry Module (TTM) for medium power (500 mW and 1 W) telemetry applications. The TTM demonstrates system integration of a multi-channel PCM encoder, lower S-band transmitter, and power regulation onto a single printed wiring board (PWB). The module is smaller than a standard business card and utilizes both COTS and M/A-COM proprietary technologies. The PCM encoder is designed for eight (8) analog inputs, eight (8) discrete inputs, and one (1) synchronous RS-422 serial interface. Data rates of 300 kbps to 6 Mbps are supported. The module incorporates a frequency programmable, phase-locked FM S-band transmitter. The transmitter utilizes M/A-COM’s new dual port VCO and high efficiency 500 mW and 1 W power amplifier MMIC’s. Additionally, switching power regulation circuits were implemented within the module to provide maximum operating efficiency. This paper reviews the design and manufacturing of the Tactical Telemetry Module (TTM) and its major components, and presents system performance data.
3

A HIGHLY INTEGRATED TELEMETRY SYSTEM FOR THE EXCALIBUR PROJECTILE

Oder, Stephen, Dearstine, Christina, Muir, John, Semuskie, Stephen, Fratta, Ralph, DiCristina, Stephen 10 1900 (has links)
ITC/USA 2005 Conference Proceedings / The Forty-First Annual International Telemetering Conference and Technical Exhibition / October 24-27, 2005 / Riviera Hotel & Convention Center, Las Vegas, Nevada / A miniature 1 Watt Tactical Telemetry Module (TTM) has been developed for the Excalibur projectile program. The TTM incorporates a multi-channel PCM encoder, lower S-band transmitter, and power regulation onto a single printed wiring board (PWB). The PCM encoder is designed for eight (8) analog inputs, four (4) discrete inputs, and one (1) synchronous RS-422 serial interface, with a total data rate of 1 Mbps. The module incorporates a digitally programmable, phase-locked FM S-band transmitter. The transmitter utilizes M/A-COM’s new dual port VCO and a high efficiency 2 W power amplifier MMIC. Additionally, switching power regulation circuits were implemented within the module to provide maximum operating efficiency. This paper reviews the environmental requirements of Excalibur, the design of the Excalibur TTM, and presents electrical and air-gun test data.
4

ANALYSIS, DESIGN, AND LABORATORY EVALUATION OF A DISTRIBUTED UNIFIED POWER FLOW CONTROLLER CONCEPT

Li, Qiang 01 January 2006 (has links)
A single-phase, buck-boost based, dual-output AC-DC converter is studied in this thesis. The converter has two DC outputs with opposite polarities, which share the same ground with the input power line. The power stage performance, including the input filter, is studied and procedure to select power components is given. The circuit model is analyzed to develop appropriate control. Zerocrossing distortion of the source input current is addressed and a solution is proposed. Experimental results are satisfactory in that a high power factor line current results for steady-state operation.
5

Estudo dos principais mecanismos de incentivo às fontes renováveis alternativas de energia no setor elétrico

Martins, Juliana Marinho Cavalcanti 16 August 2018 (has links)
Orientador: Carla Kazue Nakao Cavaliero / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-08-16T02:35:03Z (GMT). No. of bitstreams: 1 Martins_JulianaMarinhoCavalcanti_M.pdf: 986576 bytes, checksum: 2e0d46c140f02083a2c9d967645d5e63 (MD5) Previous issue date: 2010 / Resumo: Mecanismos regulatórios de incentivo às fontes renováveis alternativas de energia estão sendo adotados, em vários países, como forma de estímulo à produção de energia por meio destas fontes. Estes instrumentos sofreram algumas adaptações para se ajustarem às expectativas dos agentes de mercado e, com isso, novas metodologias foram sendo aplicadas. No âmbito internacional, o sistema Feed-in, o sistema de leilões e o sistema de quotas são os mecanismos mais aplicados. No Brasil, o estímulo à geração de energia por meio destas fontes foi adotado com maior expressão a partir do lançamento do Proinfa em 2002. Posteriormente, os leilões foram sendo incorporados na regulação do mercado de energia renovável, como forma de promover um aumento na capacidade de geração com fontes renováveis. O presente trabalho pretende caracterizar e classificar os instrumentos adotados em âmbito internacional e nacional, explicitando as diferenças e similaridades entre os mesmos. Por fim, é realizada uma análise preliminar da eficácia destes instrumentos, dando um enfoque especial aos critérios de alcance de metas, de aumento da capacidade instalada e de redução de custos das bandas tecnológicas / Abstract: Regulatory mechanisms to encourage renewable and alternative energy are being adopted in several countries as a way to stimulate the production of energy through these sources. These instruments have undergone some adjustments to fulfill the expectations of market players and thus, new methodologies have been applied. Internationally, the Feed-in system, the tender system and the quota system are the mechanisms usually applied. In Brazil, the stimulus to the generation of energy through these sources was used with greater expression from the launch of Proinfa in 2002. Subsequently, the auctions were being incorporated in the regulation of renewable energy market, in order to promote an increase in generation capacity from renewable sources. This work intend to characterize and classify the instruments adopted at international and national levels, highlighting the differences and similarities between them. Finally, we performed a preliminary analysis of the effectiveness of these instruments, with a special focus on the ability to reach policy goals, capacity growth and cost reduction of technology bands / Mestrado / Planejamento de Sistemas Energeticos / Mestre em Engenharia Mecânica
6

Eficiência dos custos operacionais das empresas de distribuição de energia elétrica no Brasil / Efficiency of operational costs of electric power distribution companies in Brazil

Semolini, Robinson, 1971- 12 March 2014 (has links)
Orientador: Rosangela Ballini / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Economia / Made available in DSpace on 2018-08-26T10:17:14Z (GMT). No. of bitstreams: 1 Semolini_Robinson_D.pdf: 2731017 bytes, checksum: c43b75ab3dc33b97fd1c449d04a74e03 (MD5) Previous issue date: 2014 / Resumo: Em substituição ao Modelo Normativo de Empresa de Referência, que vigorava no Brasil desde 2003, a Agência Nacional de Energia Elétrica (ANEEL) implementou, em 2011, metodologia de benchmarking para o cálculo dos custos operacionais regulatórios para cada uma das 63 Concessionárias de Distribuição de Energia Elétrica, baseada na média dos resultados dos modelos de Análise Envoltória de Dados (DEA) e Mínimos Quadrados Corrigidos (COLS). A partir dos problemas identificados nesta metodologia de benchmarking e, fundamentado em estudo das práticas regulatórias internacionais na aplicação de benchmarking para regular os custos operacionais de distribuidoras, o objetivo desta tese é propor uma metodologia de benchmarking para a regulação dos custos operacionais das distribuidoras de energia no Brasil, baseada nos seguintes princípios: uso de base de dados e metodologias estatísticas aplicadas; construção de método para a estimação da eficiência a partir de um modelo estruturado, interpretável e que utiliza técnicas de modelagem econométrica; consideração das particularidades do país: grande heterogeneidade climática, geográfica, socioeconômica e, principalmente, da forma de gestão e propriedade; e factível e simples de ser implementado pelo regulador para o caso brasileiro. Partindo destes princípios, as seguintes melhorias para compor a proposta foram alcançadas: (i) agrupar as distribuidoras em 3 clusters de acordo com a forma de gestão e propriedade: distribuidoras públicas, privadas independentes e privadas pertencentes a holdings. Esta clusterização mostrou ser estatisticamente significativa com relação à eficiência e à produtividade dos grupos; (ii) uso dos produtos mercado, clientes e rede, corrigindo o problema da multicolinearidade entre estas variáveis com auxilio da técnica estatística de Análise de Componentes Principais, resultando na construção de uma Variável de Escala Composta; (iii) uso do TOTEX como insumo, conforme preferência dos reguladores para tratar o incentivo das distribuidoras de contabilizarem seus custos operacionais (OPEX) como investimentos (CAPEX); (iv) inclusão da Qualidade do fornecimento como insumo, por meio da variável Energia não Suprida, para tratar o trade-off entre Qualidade, OPEX e CAPEX; (v) aplicação do modelo paramétrico de Análise de Fronteira Estocástica (SFA), recomendado como melhor método a ser utilizado, quando da presença de quantidade de dados suficientes, como o caso do Brasil; (vi) tratamento das heterogeneidades entre as distribuidoras diretamente na modelagem da função de custos, para evitar que estes fatores sejam incorretamente atribuído à ineficiência; (vii) SFA aplicado a dados em painel, por meio do modelo com Verdadeiros Efeitos Aleatórios. A eficiência estimada considerando os 7 itens para cada cluster, evidenciou ser mais adequada quando comparada aos resultados da metodologia da ANEEL. Por fim, a proposta de implementação do modelo de benchmarking, em termos de aumentar o incentivo na busca da eficiência dos custos operacionais, tendo a preocupação adicional de manter o equilíbrio na questão da manutenção dos investimentos das distribuidoras, mostrou ser mais simples, intuitiva, eficiente e factível de ser implementada / Abstract: Replacing the Normative Model of Reference Company, which prevailed in Brazil since 2003, the National Agency of Electric Energy (ANEEL) implemented, in 2011, benchmarking methodology to calculate regulatory operational costs for each of the 63 Dealers of Electric Power Distribution based on the average results of Data Envelopment Analysis (DEA) and Corrected Least Squares (COLS). Based on problems identified in the ANEEL benchmarking methodology and grounded on studies of the international regulatory practices, applied to benchmarking regulatory operational costs of distribution, the objective of this thesis is to propose a methodology of benchmarking to regulatory operational costs of the power distributors in Brazil, based on the following principles: use database and statistical applied methodologies; building method for efficiency estimation from a structured and interpretable model, using econometric modeling techniques; considerate particularities of the country: large climate heterogeneity, geography, socioeconomic and, especially, the form of management; feasible and simple to be implemented by the regulator for the Brazilian case. Based on these principles the following improvements compose the proposed methodology: (i) grouping distributors in 3 clusters according to the form of management and ownership: public, private independent and private belonging to holdings. This clustering was shown to be statistically significant with respect to the efficiency and productivity of the groups; (ii) use of the products - market, customers and network - correcting the multicollinearity problem among them, through the statistical technique of Principal Component Analysis, resulting in the construction of a Composite Scale Variable; (iii) use of TOTEX as input, preferred by regulators to address the incentive of distributors to account their operational cost (OPEX) as investments (CAPEX); (iv) inclusion of Power Supply Quality as input, using the variable Energy Not Supplied to address the trade-off between Quality, OPEX and CAPEX; (v) application of Parametric Model of Stochastic Frontier Analysis (SFA), recommended as the best method to be used when exists sufficient amount of data, which is the Brazilian case; (vi) treatment of heterogeneities among distributors directly modeling the cost function to avoid these factors being incorrectly attributed to inefficiency; (vii) SFA applied to panel data, through True Random Effects Model. The estimated efficiency considering the 7 items for each cluster, showed to be more adequate compared to the results of the ANEEL methodology. Finally, the implementation proposed to the benchmarking model, in terms of increasing the incentive to seek efficiency in operational costs, with the additional concern of conserving the balance considering the maintenance of the distribution investments, proved to be more simple, intuitive, efficient and feasible to implement / Doutorado / Desenvolvimento Economico, Espaço e Meio Ambiente / Doutor em Desenvolvimento Economico
7

Competition Law Between Old Goals and New Challenges. New tools for a ‘multi-value’ approach vis-à-vis: Digitalisation, Inequalities, and Climate Changes

Piletta Massaro, Andrea 13 December 2022 (has links)
The research question that moves the present work is whether and how competition law shall play a role in making our society more ‘sustainable’, intending this term in a broad meaning, and therefore linked to social, economic and environmental sustainability. The question raises from the awareness of the problems that are affecting our society, also if we refer at its democratic foundations. In particular, we considered that issues such as increasing income inequalities, raising market concentration rates and the even faster climate changes are topics that cannot be outside the academic analysis of the various policies. Therefore, if we try to answer at the question if competition law shall play a role in this context, the analysis should start from the very foundations of this discipline. At this purpose, in our research, we scrutinised how the most representative competition law regimes in the world - i.e., the US antitrust law and the EU competition law systems – developed during their history. This analysis is conducted by reading through legislative sources, policy statements, judicial decisions and scholar works. What emerges is that competition law shall not only be focused on mere economic and econometric objectives, such economic efficiency, but it was intended more as a structural instrument, created for preventing the concentration of an excessive degree of economic power on the same subject or on a bounce of entities. Therefore, after having affirmed this structuralist aim of competition law, it is possible to understand how every other objective shall be considered as a by-product of a healthy competitive process, and not as an end of competition law in itself. This is particularly clear in the European context, as competition law ought not to be intended as a separate or lone subject, but as a field of law well rooted into the EU and its Member States’ constitutional traditions. After having established that competition law shall play a role in the transition towards a more sustainable society, the focus moves on how this task shall be performed. For this purpose, the present research scrutinised the issues we mentioned before, by making a comparative analysis between the EU and the U.S. competition law and antitrust models and, inside the EU environment, among the various solutions adopted in the Member States. This analysis first needed to be carried out by means of an empirical assessment of the issue at stake, especially from an economic standpoint. Then, the legal tools needed in order to reach the desired outcomes were scrutinised, first by making reference to the solutions already adopted by enforcers and Courts on the basis of the existing rules, and, subsequently, new tools are analysed and proposed. In particular, the research establishes a connection between income inequalities and the increasing rates of market concentration. The latter dynamic was deemed particularly intense in the digital market context, which are characterised by market dynamics which escape from the common understanding of competition, as they lead the market to tip in favour of a firm, usually the first mover. In a nutshell, they are characterised by a sort of winner takes all structure. This field represents the core of this research, as it is where excessive market concentration shows most its detrimental effects and the need to a structuralist approach to competition law appears much needed. Therefore, this work aims to provide its contribution to the very active academic debate on this field. However, this research does not want to be limited to the digital market problem but is directed at casting lights on the need for a multi-value approach to competition law at 360 degrees, which can turn into a multi-tool enforcement to better tailor the application of competition rules to all the analysed issues, which are however interrelated thanks to the broad concept of ‘sustainability’ outlined above, in line with the Brundtland Report on sustainability issued in 1987 by the World Commission on Environment and Development. What emerges is that competition law ought to play a role in the transition towards a more sustainable economy and society. This depends on policy choices, and this work is aimed – in the realm of the current scholar debate on this topic – at providing its constructive contribution. However, what is important to affirm is that policy choices directed at establishing the multi-value and multi-tool competition law described above are not only based on progressive or hipster academic ideas, but they are deeply rooted into our societies’ constitutional traditions, and, in the end, in a healthy conception of the liberal economy itself.
8

Génération de molécules de solitons, régulation de puissance, régénération et sculpture des profils d'impulsion au sein d'un laser à fibre multifonction / Generation of soliton molecules, power regulation, regeneration and sculpting of pulse profiles within a multifunction fiber laser

Igbonacho, Bici Chinauyi Junior 21 December 2018 (has links)
Les travaux de cette thèse s'efforcent d'apporter une solution au problème persistant de grande pauvreté des lasers à fibre à modes bloqués, en termes de fonctionnalités et de flexibilité. La thèse propose une cavité laser fibrée ayant comme spécificité d'être multifonctionnelle. La cavité est dotée de composants accordables, qui apportent la flexibilité nécessaire pour réaliser des fonctions allant de la génération d’impulsions aux profils complexes (solitons, bi-solitons, tri-solitons, etc) jusqu’à la sculpture des profils d’impulsion, en passant par la régulation des puissances crête, et la régénération de profils d’intensités sévèrement dégradés. La cavité laser que nous proposons a comme spécificité d'être pilotée par un composant clé, qui est un miroir à boucle optique non-linéaire (NOLM : Nonlinear Optical Loop Mirror) multifonction. Nous avons conçu ce NOLM en apportant des modifications structurelles dans l'architecture usuelle de ce dispositif, et en lui adjoignant : une fibre compensatrice de dispersion, un filtre passe bande à bande passante accordable, et un amplificateur (précédé d'un filtre égaliseur de gain, selon le besoin). Le NOLM ainsi conçu est doté de deux paramètres manuellement accordables, à savoir: la bande passante du filtre passe bande et la puissance de pompage de l'amplificateur. Ces deux paramètres permettent de régler sa fonction de transfert, et à accroître ainsi ses fonctionnalités et sa flexibilité. Ainsi, en plus de son rôle comme élément déclencheur du blocage de modes, ce NOLM réalise des fonctions optiques essentielles telles que la régénération des profils d'intensité fortement dégradés par des phénomènes de propagation ; ce qui contribue au renforcement de la stabilité du laser. Nous démontrons également la possibilité de réguler la puissance crête des impulsions, en la verrouillant à une valeur prédéfinie. Nous montrons enfin que le laser multifonction offre la possibilité de réaliser la sculpture des profils d'impulsion, c'est-à-dire, de générer des impulsions dotées d'une puissance crête et une largeur temporelle fixés à l'avance via un réglage approprié des paramètres de contrôle du NOLM.Les applications visées par ce laser multifonction, concernent toutes les activités qui requièrent des sources d'impulsions finement accordables, tant au niveau de puissance crête des impulsions que de leur largeur temporelle. Ces activités, nombreuses dans le domaine Télécom, incluent les opérations de remise en forme des porteuses d'information, les opérations de compression ou étirement de profil d'impulsion, les diagnostics de composants optiques et contrôles non destructifs des lignes de transmission par réflectométrie. / The work of this thesis strives to provide a solution to the persistent problem of poverty of mode-locked fiber lasers, in terms of functionality and flexibility. The thesis proposes a fiber-laser cavity having the specificity of being multifunctional. The cavity is equipped with tunable components, which provide the flexibility to realize functions ranging from the generation of pulses with complex profiles (solitons, bi-solitons, tri-solitons, etc.) up to the carving of pulse profiles, passing through the regulation of peak powers, and the regeneration of severely degraded intensity profiles. The laser cavity that we propose has the specificity of being controlled by a key component, which is a multifunctional nonlinear optical loop mirror (NOLM). We have designed this NOLM by making structural modifications in the usual architecture of this device, and by adding to it: a dispersion compensating fiber, a bandpass filter with tunable bandwidth, and an amplifier (preceded by a gain flattening filter, as needed) with tunable gain. These two parameters make it possible to adjust its transfer function, and thus to increase its functionalities and its flexibility. Thus, in addition to its role as a trigger for mode locking, this NOLM performs essential optical functions such as the regeneration of strongly degraded intensity profiles; which contributes to strengthening the stability of the laser.We also show the possibility of regulating the pulse peak power by locking it around a predefined value. Finally, we show that the multifunction laser offers the possibility to carve pulse profiles, that is, to generate pulses endowed with a peak power and a temporal width set in advance through an appropriate adjustment of the NOLM control parameters. The applications targeted by this multifunction laser are those requiring pulses with finely tunable peak power and temporal width. These activities, include the pulse reshaping in Telecoms, operations of compression or stretching of pulse profiles, optical component diagnostics, and non-destructive control of transmission lines
9

Využití velkokapacitních baterií v provozu Červený Mlýn k rozšíření podpůrných služeb vůči ČEPS / Utilization of Battery Energy Storage Systems in the Červený Mlýn Plant to Extend Support Services to ČEPS

Zajac, Tomáš January 2018 (has links)
The aim of master´s thesis is analysis of utilization of large-capacity battery energy storage systems, used in cooperation with facility Červený mlýn to supply ancillary services to ČEPS, a.s.. In the first part, categorisation of ancillary services is presented. Within the categorisation technical and legislative requirements on subjects providing individual services are defined, the overview of ancillary services providers is listed and the mechanisms of ancillary services procurement are elucidated. The thesis continues with an overview of accumulation technologies used in high-capacity application around the world and in Czech republic. Subsequently three technologies are presented – Li-Ion, NaS and VRB, which are considered as suitable technological solutions for given application. The last part of thesis deals with specification of parameters of the accumulation system, with selection of installation site within the facility and with description of operating modes while providing ancillary services. In order to evaluate the investment from an economic point of view, a model of sensitivity analysis is created and described and its outputs are presented and discussed at the end of the thesis.
10

Posouzení možnosti provozu zdrojů v dané oblasti při nestandardních provozních stavech sítě VN / Evaluation of nonstandard operation possibilities of power sources in MV network

Čáslava, Jiří January 2012 (has links)
This Master's thesis deals with solution of nonstandard operation connection of E.ON's 22kV distribution network in given area, considering the possibilities of operating dispersed electric power sources currently available, as well as possible power sources connected to the distribution network in the future and its potential operation limitation. A part of this paper is a description of calculation methods used for network evaluation in steady state, with emphasis on linear calculations used by E-Vlivy program, in which the operational possibilities are simulated. Therefore, a description of this program is also included. Suggested operation possibilities correspond with E.ON's valid distribution network operation rules. The outcome of this paper will serve to E.ON's 22kV network's controllers as materials for network operating in nonstandard operation states.

Page generated in 0.0949 seconds