This Thesis examines the operation and dynamic performance of a single-stage, single-switch power factor corrector, S4 PFC, with an integrated magnetic device, IM. Also detailed isthe development and analysis of a high power light emitting diode, HP LED, power factorcorrection converter and proposed voltage regulation band control approach.The S4 PFC consists of a cascaded discontinuous current mode, DCM, boost stage anda continuous current mode, CCM, forward converter. The S4 PFC achieves a high powerfactor, low input current harmonics and a regulated voltage output, utilising a singleMOSFET. A steady-state analysis of the S4 PFC with the IM is performed, identifying theoperating boundary conditions for the DCM power factor correction stage and the CCMoutput voltage regulation stage. Integrated magnetic analysis focuses on understanding theperformance, operation and generated flux paths within the IM core, ensuring the device doesnot affect the normal operation of the converter power stage. A design method for the S4 PFCwith IM component is developed along with a cost analysis of this approach. Analysis predictsthe performance of the S4 PFC and the IM, and the theoretical work is validated by MATLABand SABER simulations and measurements of a 180 W prototype converter.It is not only the development of new topological approaches that drives theadvancement of power electronic techniques. The recent emergence of HP LEDs has led to aflurry of new application areas for these devices. A DCM buck-boost converter performs thepower factor correction and energy storage, and a cascaded boundary conduction current modebuck converter regulates the current through the LED arrays. To match the useful operatinglifetime of the HP LEDs, electrolytic capacitors are not used in the PFC converter. Analysisexamines the operation and dynamic characteristics of a PFC converter with low capacitiveenergy storage capacity and its implications on the control method. A modified regulationband control approach is proposed to ensure a high power factor, low input current harmonicsand output voltage regulation of the PFC stage. Small signal analysis describes the dynamicperformance of the PFC converter, Circle Criterion is used to determine the loop stability.Theoretical work is validated by SABER and MATLAB simulations and measurements of a180 W prototype street luminaire.

Renewable energy source plays an important role in the energy cogeneration and distribution. Traditional solar-based inverter system is two stages in cascaded, which has a simpler controller but low efficiency. A new solar-based single-stage grid-connected inverter system can achieve higher efficiency by reducing the power semiconductor switching loss and output stable and synchronized sinusoid current into the utility grid. Controlled by the digital signal processor, the inverter can also draw maximum power from the solar array, thereby maximizing the utilization of the solar array. In Chapter 1, a comparison between the traditional two-stage inverter and the single-stage inverter is made. To increase the ability of power processing and enhance the efficiency further, a full-bridge topology is chosen, which applies the phase-shift technique to achieve zero-voltage transition. In Chapter 2, average-mode and switch-mode Pspice simulations are applied. All the features of the inverter system are verified, such as stability, zero voltage transition and feed-forward compensation, etc. All these simulation results provide useful design tips for prototyping. In Chapter 3, a phase-shift controller is designed based on UCC3895. Also, a detailed design procedure is given, including key components selection, transformer and inductor design and driver circuits design. In Chapter 4, experimental results of a prototype DC/DC converter are presented and analyzed. By optimization of the circuit, the problems of the prototype are solved and the prototype is working stably. The thesis' conclusion is given in Chapter 5.

This thesis introduces the design and analysis of a single-stage inverter. A circuit was designed and simulated as a proof of concept to investigate the possibility of using boost and buck-boost converters to provide an AC output. The proposed circuit utilizes non-synchronous boost and buck-boost converters due to their simplicity in control signals as opposed to synchronous converters. The application of the proposed inverter is for use with individual solar cells. The aim of the inverter for a single cell is to improve the efficiency of a solar panel, whose performance is limited to the performance of the least efficient cell. With each cell independent of any other cell in the solar panel, the overall efficiency of the panel can be improved. This circuit uses a 3.6VDC input from the solar cell to produce a 10VPP 60Hz square wave output. The inverter consists of a solar cell, two DC-DC converters, two linear dropout (LDO) regulators, a square wave generator, and a switching circuit . The design and analysis of all parts were investigated individually in detail. The different parts of the circuit were then simulated using LTspice before testing the overall circuit. Simulation results demonstrate the feasibility of the proposed inverter with all design requirements but efficiency meeting or exceeding the goals.

Yes / The single-stage flyback Photovoltaic (PV) micro-inverter is considered as a simple and small in size topology but requires expensive digital microcontrollers such as Field-Programmable Gate Array (FPGA) or Digital Signal Processor (DSP) to increase the system efficiency, this would increase the cost of the overall system. To solve this problem, based on a single-stage flyback structure, this paper proposed a low cost and simple analog-digital control scheme. This control scheme is implemented using a low cost ATMega microcontroller built in the Arduino Uno board and some analog operational amplifiers. First, the single-stage flyback topology is analyzed theoretically and then the design consideration is obtained. Second, a 120 W prototype was developed in the laboratory to validate the proposed control. To prove the effectiveness of this control, we compared the cost price, overall system efficiency, and THD values of the proposed results with the results obtained by the literature. So, a low system component, single power stage, cheap control scheme, and decent efficiency are achieved by the proposed system. Finally, the experimental results present that the proposed system has a maximum efficiency of 91%, with good values of the total harmonic distortion (THD) compared to the results of other authors / This work was supported in-part by Innovate UK GCRF Energy Catalyst PiCREST project under Grant number 41358, in-part by British Academy GCRF COMPENSE project under Grant GCRFNGR3\1541

Purpose: The purpose of the study is to identify, design and apply a method for operational production planning. The purpose of the method is that it takes into account the respective demand patterns of the articles, which determines the choice of calculation model and that the method also takes into account the production capacity limitation set. The result can be applied as a basis for decision-making for small and medium-sized manufacturing companies that are facing an expansion. Objective: The following research question was the main objective of this study.How would an appropriate operational planning method be shaped according to the specific characteristics of the products and their diverse demand patterns in small and medium-sized manufacturing companies with capacity limiters? Method: The study is a qualitative one-case study with quantitative elements. The empirical data used in the study was collected through unstructured and semi-structured interviews where the snowball effect has been applied and also observations have been performed. Results: The study has enabled a higher degree of utilization of the capacity limitation set, by developing standardized block sizes. The first step was to identify demand patterns into which the studied articles could be categorized. The demand pattern was applied in order to be able to apply the correct calculation model to the correct article. The calculation model was then standardized by applying PoT to be able to obtain standardized block sizes. The method was illustrated in a Gantt chart to demonstrate its usefulness. / Syfte: Studiens syfte är att identifiera, utforma och applicera en metod för operativ produktionsplanering. Ändamålet med metoden är att den tar hänsyn till artiklarnas respektive efterfrågemönster vilket avgör valet av beräkningsmodell samt att metoden tar även hänsyn till produktionens kapacitetsbegränsning ställare. Resultatet kan appliceras som beslutsunderlag för små samt medelstora tillverkande företag som står inför en expansion. Forskningsfråga: Följande forskningsfråga var objektet för denna studie. Hur skulle en lämplig operativ planering formas utefter artiklarnas specifika egenskaper och deras olikartade efterfrågemönster hos små och medelstora tillverkande företag med kapacitetsbegränsningen ställare? Metod: Studien är en kvalitativ en-fallstudie med kvantitativa inslag. Den empiriska data som använts i studie än insamlad genom ostrukturerade samt semistrukturerade intervjuer där snöbollseffekten tillämpats och även observationer har utförts. Resultat: Studien har möjliggjort en högre utnyttjandegrad av kapacitetsbegränsningen ställare, genom att framta standardiserade blockstorlekar. Första steget var att identifiera efterfrågemönster som de studerade artiklarna kunnat kategoriseras in i. Efterfrågemönstret har tillämpats för att kunna använda rätt beräkningsmodell på rätt artikel. Beräkningsmodellen standardiserades därefter genom tillämpning av PoT för att kunna erhålla standardiserade blockstorlekar. Metoden illustrerades i ett Gantt-schema för att påvisa dess användbarhet.

Mapas pedológicos são fontes de informações primordiais para planejamento e manejo de uso do solo, porém apresentam altos custos de produção. A fim de produzir mapas de solos a partir de mapas existentes, o presente trabalho objetiva testar e comparar métodos de classificação em estágio único (regressões logísticas múltiplas multinomiais e Bayes) e em estágios múltiplos (CART, J48 e LMT) com utilização de sistemas de informações geográficas e de variáveis geomorfométricas para produção de mapas pedológicos com legenda original e simplificada. A base de dados foi gerenciada em ambiente ArcGis onde as variáveis e o mapa original foram relacionados através de amostras de treinamento para os algoritmos. O resultado dos algoritmos obtidos no software Weka foram implementados no ArcGis para a confecção dos mapas. Foram gerados matrizes de erros para análise de acurácias dos mapas. As variáveis geomorfométricas de declividade, perfil e plano de curvatura, elevação e índice de umidade topográfica são aquelas que melhor explicam a distribuição espacial das classes de solo. Os métodos de classificação em estágio múltiplo apresentaram sensíveis melhoras nas acurácias globais, porém significativas melhoras nos índices Kappa. A utilização de legenda simplificada aumentou significativamente as acurácias do produtor e do usuário, porém sensível melhora na acurácia global e índice Kappa. / Soil maps are sources of important information for land planning and management, but are expensive to produce. This study proposes testing and comparing single stage classification methods (multiple multinomial logistic regression and Bayes) and multiple stage classification methods (CART, J48 and LMT) using geographic information system and terrain parameters for producing soil maps with both original and simplified legend. In ArcGis environment terrain parameters and original soil map were sampled for training algoritms. The results from statistical software Weka were implemented in ArcGis environment to generate digital soil maps. Error matrices were genereted for analysis accuracies of the maps.The terrain parameters that best explained soil distribution were slope, profile and planar curvature, elevation, and topographic wetness index. The multiple stage classification methods showed small improvements in overall accuracies and large improvements in the Kappa index. Simplification of the original legend significantly increased the producer and user accuracies, however produced small improvements in overall accuracies and Kappa index.

In this work, single stage power factor corrected AC/DC converters for LEDs / single stage Flyback converter having different configuration from the traditional Flyback and single stage SEPIC converter is investigated. The study involves analysis, circuit design, performance comparisons and implementation. The study covers LEDs / their developments, characteristics and state-of-art in this new technology. The circuits are investigated by means of computer simulations. Operating principles and operating modes are studied along with design calculations. After applying prototypes in laboratory, the simulation results and theoretical analyses are confirmed. The single stage Flyback converter has high voltage input (220-240 Vac), and the output feeds up to 216 HB-LEDs, with the ratings of 24 V, 3.25 A with 90 W. The single stage SEPIC converter with universal input (80-265 Vac) has an output that feeds 21 power LEDs, with 67 V, 0.30 and 20 W ratings.

No description available.

Mapas pedológicos são fontes de informações primordiais para planejamento e manejo de uso do solo, porém apresentam altos custos de produção. A fim de produzir mapas de solos a partir de mapas existentes, o presente trabalho objetiva testar e comparar métodos de classificação em estágio único (regressões logísticas múltiplas multinomiais e Bayes) e em estágios múltiplos (CART, J48 e LMT) com utilização de sistemas de informações geográficas e de variáveis geomorfométricas para produção de mapas pedológicos com legenda original e simplificada. A base de dados foi gerenciada em ambiente ArcGis onde as variáveis e o mapa original foram relacionados através de amostras de treinamento para os algoritmos. O resultado dos algoritmos obtidos no software Weka foram implementados no ArcGis para a confecção dos mapas. Foram gerados matrizes de erros para análise de acurácias dos mapas. As variáveis geomorfométricas de declividade, perfil e plano de curvatura, elevação e índice de umidade topográfica são aquelas que melhor explicam a distribuição espacial das classes de solo. Os métodos de classificação em estágio múltiplo apresentaram sensíveis melhoras nas acurácias globais, porém significativas melhoras nos índices Kappa. A utilização de legenda simplificada aumentou significativamente as acurácias do produtor e do usuário, porém sensível melhora na acurácia global e índice Kappa. / Soil maps are sources of important information for land planning and management, but are expensive to produce. This study proposes testing and comparing single stage classification methods (multiple multinomial logistic regression and Bayes) and multiple stage classification methods (CART, J48 and LMT) using geographic information system and terrain parameters for producing soil maps with both original and simplified legend. In ArcGis environment terrain parameters and original soil map were sampled for training algoritms. The results from statistical software Weka were implemented in ArcGis environment to generate digital soil maps. Error matrices were genereted for analysis accuracies of the maps.The terrain parameters that best explained soil distribution were slope, profile and planar curvature, elevation, and topographic wetness index. The multiple stage classification methods showed small improvements in overall accuracies and large improvements in the Kappa index. Simplification of the original legend significantly increased the producer and user accuracies, however produced small improvements in overall accuracies and Kappa index.

Mapas pedológicos são fontes de informações primordiais para planejamento e manejo de uso do solo, porém apresentam altos custos de produção. A fim de produzir mapas de solos a partir de mapas existentes, o presente trabalho objetiva testar e comparar métodos de classificação em estágio único (regressões logísticas múltiplas multinomiais e Bayes) e em estágios múltiplos (CART, J48 e LMT) com utilização de sistemas de informações geográficas e de variáveis geomorfométricas para produção de mapas pedológicos com legenda original e simplificada. A base de dados foi gerenciada em ambiente ArcGis onde as variáveis e o mapa original foram relacionados através de amostras de treinamento para os algoritmos. O resultado dos algoritmos obtidos no software Weka foram implementados no ArcGis para a confecção dos mapas. Foram gerados matrizes de erros para análise de acurácias dos mapas. As variáveis geomorfométricas de declividade, perfil e plano de curvatura, elevação e índice de umidade topográfica são aquelas que melhor explicam a distribuição espacial das classes de solo. Os métodos de classificação em estágio múltiplo apresentaram sensíveis melhoras nas acurácias globais, porém significativas melhoras nos índices Kappa. A utilização de legenda simplificada aumentou significativamente as acurácias do produtor e do usuário, porém sensível melhora na acurácia global e índice Kappa. / Soil maps are sources of important information for land planning and management, but are expensive to produce. This study proposes testing and comparing single stage classification methods (multiple multinomial logistic regression and Bayes) and multiple stage classification methods (CART, J48 and LMT) using geographic information system and terrain parameters for producing soil maps with both original and simplified legend. In ArcGis environment terrain parameters and original soil map were sampled for training algoritms. The results from statistical software Weka were implemented in ArcGis environment to generate digital soil maps. Error matrices were genereted for analysis accuracies of the maps.The terrain parameters that best explained soil distribution were slope, profile and planar curvature, elevation, and topographic wetness index. The multiple stage classification methods showed small improvements in overall accuracies and large improvements in the Kappa index. Simplification of the original legend significantly increased the producer and user accuracies, however produced small improvements in overall accuracies and Kappa index.