Uso de técnicas de otimização baseadas em derivadas como suporte do planejamento operacional de redes de distribuição de energia elétrica

The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developing the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. It s important to point out that, in spite of the loads being normally connected to the transformer s secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

Mapa de Conteúdos e Mapa de Dependências:Ferramentas Pedagógicas para uma Metodologia de Planejamento baseada em Objetivos Educacionais e sua Implementação em um Ambiente Virtual de Aprendizagem

Furthered mainly by new technologies, the expansion of distance education has created a demand for tools and methodologies to enhance teaching techniques based on proven pedagogical theories. Such methodologies must also be applied in the so-called Virtual Learning Environments. The aim of this work is to present a planning methodology based on known pedagogical theories which contributes to the incorporation of assessment in the process of teaching and learning. With this in mind, the pertinent literature was reviewed in order to identify the key pedagogical concepts needed to the definition of this methodology and a descriptive approach was used to establish current relations between this conceptual framework and distance education. As a result of this procedure, the Contents Map and the Dependence Map were specified and implemented, two teaching tools that promote the planning of a course by taking into account assessment still in this early stage. Inserted on Moodle, the developed tools were tested in a course of distance learning for practical observation of the involved concepts. It could be verified that the methodology proposed by the above-mentioned tools is in fact helpful in course planning and in strengthening educational assessment, placing the student as central element in the process of teaching and learning

Uso de técnicas de otimização baseadas em derivadas como suporte do planejamento operacional de redes de distribuição de energia elétrica

The usual programs for load flow calculation were in general developped aiming the simulation of electric energy transmission, subtransmission and distribution systems. However, the mathematical methods and algorithms used by the formulations were based, in majority, just on the characteristics of the transmittion systems, which were the main concern focus of engineers and researchers. Though, the physical characteristics of these systems are quite different from the distribution ones. In the transmission systems, the voltage levels are high and the lines are generally very long. These aspects contribute the capacitive and inductive effects that appear in the system to have a considerable influence in the values of the interest quantities, reason why they should be taken into consideration. Still in the transmission systems, the loads have a macro nature, as for example, cities, neiborhoods, or big industries. These loads are, generally, practically balanced, what reduces the necessity of utilization of three-phase methodology for the load flow calculation. Distribution systems, on the other hand, present different characteristics: the voltage levels are small in comparison to the transmission ones. This almost annul the capacitive effects of the lines. The loads are, in this case, transformers, in whose secondaries are connected small consumers, in a sort of times, mono-phase ones, so that the probability of finding an unbalanced circuit is high. This way, the utilization of three-phase methodologies assumes an important dimension. Besides, equipments like voltage regulators, that use simultaneously the concepts of phase and line voltage in their functioning, need a three-phase methodology, in order to allow the simulation of their real behavior. For the exposed reasons, initially was developped, in the scope of this work, a method for three-phase load flow calculation in order to simulate the steady-state behaviour of distribution systems. Aiming to achieve this goal, the Power Summation Algorithm was used, as a base for developping the three phase method. This algorithm was already widely tested and approved by researchers and engineers in the simulation of radial electric energy distribution systems, mainly for single-phase representation. By our formulation, lines are modeled in three-phase circuits, considering the magnetic coupling between the phases; but the earth effect is considered through the Carson reduction. Its important to point out that, in spite of the loads being normally connected to the transformers secondaries, was considered the hypothesis of existence of star or delta loads connected to the primary circuit. To perform the simulation of voltage regulators, a new model was utilized, allowing the simulation of various types of configurations, according to their real functioning. Finally, was considered the possibility of representation of switches with current measuring in various points of the feeder. The loads are adjusted during the iteractive process, in order to match the current in each switch, converging to the measured value specified by the input data. In a second stage of the work, sensibility parameters were derived taking as base the described load flow, with the objective of suporting further optimization processes. This parameters are found by calculating of the partial derivatives of a variable in respect to another, in general, voltages, losses and reactive powers. After describing the calculation of the sensibility parameters, the Gradient Method was presented, using these parameters to optimize an objective function, that will be defined for each type of study. The first one refers to the reduction of technical losses in a medium voltage feeder, through the installation of capacitor banks; the second one refers to the problem of correction of voltage profile, through the instalation of capacitor banks or voltage regulators. In case of the losses reduction will be considered, as objective function, the sum of the losses in all the parts of the system. To the correction of the voltage profile, the objective function will be the sum of the square voltage deviations in each node, in respect to the rated voltage. In the end of the work, results of application of the described methods in some feeders are presented, aiming to give insight about their performance and acuity

Localização e planejamento de caminhos para um robô humanóide e um robô escravo com rodas

This work presents the localization and path planning systems for two robots: a non-instrumented humanoid and a slave wheeled robot. The localization of wheeled robot is made using odometry information and landmark detection. These informations are fused using a Extended Kalman Filter. The relative position of humanoid is acquired fusing (using another Kalman Filter) the wheeled robot pose with the characteristics of the landmark on the back of humanoid. Knowing the wheeled robot position and the humanoid relative position in relation to it, we acquired the absolute position of humanoid. The path planning system was developed to provide the cooperative movement of the two robots,incorporating the visibility restrictions of the robotic system

Planejamento cooperativo de tarefas em um ambiente de futebol de robôs

Este trabalho apresenta o desenvolvimento de um método de coordenação e cooperação para uma frota de mini-robôs móveis. O escopo do desenvolvimento é o futebol de robôs. Trata-se de uma plataforma bem estruturada, dinâmica e desenvolvida no mundo inteiro. O futebol de robôs envolve diversos campos do conhecimento incluindo: visão computacional, teoria de controle, desenvolvimento de circuitos microcontrolados, planejamento cooperativo, entre outros. A título de organização os sistema foi dividido em cinco módulos: robô, visão, localização, planejamento e controle. O foco do trabalho se limita ao módulo de planejamento. Para auxiliar seu desenvolvimento um simulador do sistema foi implementado. O simulador funciona em tempo real e substitui os robôs reais. Dessa forma os outros módulos permanecem praticamente inalterados durante uma simulação ou execução com robôs reais. Para organizar o comportamento dos robôs e produzir a cooperação entre eles foi adotada uma arquitetura hierarquizada: no mais alto nível está a escolha do estilo de jogo do time; logo abaixo decide-se o papel que cada jogador deve assumir; associado ao papel temos uma ação específica e finalmente calcula-se a referência de movimento do robô. O papel de um robô dita o comportamento do robô na dada ocasião. Os papéis são alocados dinamicamente durante o jogo de forma que um mesmo robô pode assumir diferentes papéis no decorrer da partida

Avaliação da secagem do bagaço de cajá usando planejamento fatorial composto central

This work deals with the kinetics assay of Cajá (Spondias mombin L.) bagasse drying by an experimental design using a tray dryer. In order to add-value to this product a kinetic study has been carried out. A central composite experimental design has been carried out to evaluate the influence of the operational variables: input air temperature (55; 65 e 75ºC); the drying air velocity (3.2; 4.6 e 6.0 m/s) and the fixed bed thickness (0.8; 1.2 e 1.6 cm) and as response variable the the moisture content (dry basis). The results showed that the diffusional Fick model fitted quite well the experimental data. The best condition found has been input air temperature of 75ºC, drying air velocity of 6.0 m/s as well as fixed bed thickness of 0.8 cm. The experimental design assay showed that the main effects as well as the second ones were significant at 95% confindance level. The best operational condition according to statistical planning was 75 oC input air temperature, 6.0 m.s-1 drying air velocity and 0.8 cm fixed bed thickness. In this case, the equilibrium moisture content (1.3% dry basis) occured at 220 minutes

Planejamento experimental aplicada a um novo separador líquido-líquido utilizado no tratamento de águas residuais contaminadas com petróleo

The present work had as objective to apply an experimental planning aiming at to improve the efficiency of separation of a new type of mixer-settler applied to treat waste water contaminated with oil. An unity in scale of laboratory, was installed in the Post-graduation Program of Chemical Engineering of UFRN. It was constructed in partnership with Petrobras S.A. This called device Misturador-Decantador a Inversão de Fases (MDIF) , possess features of conventional mixer-settler and spray column type. The equipment is composed of three main parts: mixing chamber; chamber of decantation and chamber of separation. The efficiency of separation is evaluated analyzing the oil concentrations in water in the feed and the output of the device. For the analysis one used the gravimetric method of oil and greases analysis (TOG). The system in study is a water of formation emulsified with oil. The used extractant is a mixture of Turpentine spirit hydro-carbons, supplied for Petrobras. It was applied, for otimization of the efficiency of separation of the equipment, an experimental planning of the composite central type, having as factorial portion fractionary factorial planning 2 5-2, with the magnifying of the type star and five replications in the central point. In this work, the following independents variables were studied: contents of oil in the feed of the device; volumetric ratio (O/A); total flowrate ; agitation in the mixing chamber and height of the organic bed. Minimum and maximum limits for the studied variables had been fixed according previous works. The analysis of variance for the equation of the empirical model, revealed statistically significant and useful results for predictions ends. The variance analysis also presented the distribution of the error as a normal distribution and was observed that as the dispersions do not depend on the levels of the factors, the independence assumption can be verified. The variation around the average is explained by 98.98%, or either, equal to the maximum value, being the smoothing of the model in relation to the experimental points of 0,98981. The results present a strong interaction between the variable oil contents in the feed and agitation in the mixing chamber, having great and positive influence in the separation efficiency. Another variable that presented a great positive influence was the height of the organic bed. The best results of separation efficiency had been obtained for high flowrates when associates the high oil concentrations and high agitation. The results of the present work had shown excellent agreement with the results carried out through previous works with the mixer-settler of phase inversion

Otimização do processo de flotação de emulsão óleo/água através do planejamento fatorial completo

In recent decades, the generation of solid and liquid waste has increased substantially due to increased industrial activity that is directly linked to economic growth. For that is the most efficient process, it is inevitable generation of such wastes. In the oil industry, a major waste generated in oil exploration is produced water, which due to its complex composition and the large amount generated, has become a challenge, given the restrictions imposed by environmental laws regarding their disposal, making if necessary create alternatives for reuse or treatment in order to reduce the content of contaminants and reduce the harmful effects to the environment. This water can be present in free form or emulsified with the oil, when in the form of an emulsion of oil-water type, it is necessary to use chemicals to promote the separation and flotation is the treatment method which has proved to be more efficient, for it can remove much of the emulsified oil when compared to other methods. In this context, the object of this work was to study the individual effects and interactions of some physicochemical parameters of operations, based on previous work to a flotation cell used in the separation of synthetic emulsion oil / water in order to optimize the efficiency of the separation process through of the 24 full factorial design with center point. The response variables to evaluate the separation efficiency was the percentage of color and turbidity removal. The independent variables were: concentration of de-emulsifying, oil content in water, salinity and pH, these being fixed, minimum and maximum limits. The analysis of variance for the equation of the empirical model, was statistically significant and useful for predictive purposes the separation efficiency of the floater with R2 > 90%. The results showed that the oil content in water and the interaction between the oil content in water and salinity, showed the highest values of the estimated effects among all the factors investigated, having great and positive influence on the separation efficiency. By analyzing the response surface was determined maximum removal efficiency above 90% for both measured for turbidity as a measure of color when in a saline medium (30 g/L), the high oil concentrations (306 ppm) using low concentrations of de-emulsifying (1,1 ppm) and at pH close to neutral

Comparação entre planejamento estatístico experimental e análise dimensional em operações de mistura e separação para sistema óleo-água

This work aims to determine a better methodology to help predicting some operational parameters to a new design of mixer-settler on treating wastewater produced by petroleum industry, called MDIF (Misturador-Decantador à Inversão de Fases/ Mixer-Settler based on Phase Inversion MSPI). The data from this research were obtained from the wastewater treatment unit, called MSPI-TU, installed on a wastewater treatment plant (WTP) of PETROBRAS/UO-RNCE. The importance in determining the better methodology to predict the results of separation and extraction efficiency of the equipment, contributes significantly to determine the optimum operating variables for the control of the unit. The study was based on a comparison among the experimental efficiency (E) obtained by operating MSPI-TU, the efficiency obtained by experimental design equation (Eplan) from the software Statistica Experimental Design® (version 7.0), and the other obtained from a modeling equation based on a dimensional analysis (Ecalc). The results shows that the experimental design equation gives a good prediction of the unit efficiencies with better data reliability, regarding to the condition before a run operation. The average deviation between the proposed by statistic planning model equation and experimental data was 0.13%. On the other hand, the efficiency calculated by the equation which represents the dimensional analysis, may result on important relative deviations (up 70%). Thus, the experimental design is confirmed as a reliable tool, with regard the experimental data processing of the MSPI-TU

Planejamento dos recursos hídricos da bacia hidrográfica do rio Seridó, no Rio Grande do Norte

The present research has the purpose of planning the management of the water resources of the Seridó River watershed, in the state of Rio Grande do Norte, Brazil. It has an emphasis on the amount of surface water available in this region, to provide a sustainable water supply. Based on data and information collected from public departments responsible for the management of the water resources of the Rio Grande do Norte state, well as on researches related to water resources , a watershed balance was done, and the results suggested the transposition of the waters from the Piranhas-Açu river watershed taken from the Oiticica and Armando Ribeiro Gonçalves reservoirs, integrated with the construction of 2 hidroelectrical plants and 2 elevation stations, to pump the amount of water needed to the expected demand in some public dams of the region until 2020. So, with the use of the surface water potential that exists in the region, it was demonstrated that, on the contrary of the public policies implemented in the past and in the current by the federal and state realm, it is possible to supply the currently water demands and also the future ones, in a sustainable way, without the need of importing outter water to the respective watershed. Finally, it was proposed the implementation of the Water Resources Plan in the Seridó region WRPS, aiming at providing an auto-sustainable development by significantly diminishing the effects of the dry seasons in that region, by considering the economic, social and environmental sustainability

Mapeamento geoambiental do campo de dunas Pirangi-Potengi com ênfase a San Vale e Lagoinha Natal/RN: um instrumento de apoio ao planejamento ambiental

The city of Natal-RN is constructed on dune areas with wavy relives softly waved and green areas that help to keep a pleasant climate, amongst these is distinguished field Pirangi-Potengi the dune with the areas of San Vale and Lagoinha. These environments are being substituted gradual for property and other workmanships of engineering on behalf of the urban expansion. This study the elaboration of a geoambiental mapping of Field had as objective generality Pirangi-Potengi the Dune with emphasis the San Vale and Lagoinha in Natal-RN. The done mapping had as objective specific to elaborate a vegetation map, a map of registers in cadastre of ambient problems to dunes, a map of flooding susceptibility, a map of vulnerability to the underground water contamination and a map of use and occupation of the ground. Of the carried through analysis, the area in study reveals sufficiently degraded, remaining only few green areas and dunares, as well as, the vulnerable presence of areas of vulnerability in floods and areas the contamination of the water-bearing one. The gotten results allow to affirm that this type of mapping, is of great importance for analysis and evaluation of the environment of the city

O Planejamento estratégico sem plano: ícones urbanos e dinâmica imobiliária em Natal

The model of strategic city planning is applied to Latin American and Brazilian cities since the 1990s. Notwithstanding, in many cities, the production of space has not followed the international model stricto sensu, but a variation of the model, here called, strategic city planning without a plan or peripheral (or yet incomplete) urban entrepreneurialism . This seeks to build city attributes in order to qualify cities for the competitive international and/or regional markets. This includes the production of iconic buildings and structures, here called urban icons. They rapidly become symbols in the contemporary city landscape, facilitating the promotions of the city for tourism and business. This also helps produce charismatic leaderships. However, what it does best is to promote real estate development. This dissertation seeks to understand the role of iconic buildings in the promotion of real estate business in Natal, especially how it helps to fuel prices in the market. The research is done by use of interviews with civil servants and private entrepreneurs related to real estate business

Gravidez tardia: bem-estar subjetivo e percepção da gestação

The subjective well- being (SWB) is formed by global judgments of satisfaction with life, or with peculiar domains the positive and the negative emotional experiences. The perception in turn, is the process of interpretive process of sensory data with cognitive or informative sense, absorbed in function of a context. From this perspective, the research aimed to evaluate SWB and the perception of advanced age pregnant women. Participated in the survey 80 pregnant with 35 years old or older (Group A or older) and 80 pregnant aged between 20 and 34 years old (Group B or young adults). The instruments used were: the scale of subjective well-being and a questionnaire, that included sociodemographic informations, items about pregnancy and a statement based on the Free Association of Words Technique (FAWT) to approach the perception of pregnancy. The data from the questionnaire and scale, in order to compare the data between groups suffered descriptive and inferential statistical analyzes. The analyzes performed with chi-square test among groups, which had values that were statistically significant, with the sociodemographic variables the type of contraceptive and health problems. The indicators of the SWB had further more by means in groups. The results of the Wilcoxon's test that there were no differences between the groups referred above. In the relation indicators of well being with variables age, education and income, some associations were significant. In addition, the words derived from the (FAWT) were analyzed using the software Programmer s Permenttant l´Analyse des Evocation (EVOC2000) and categorized according to content analysis of Bardin in three thematic categories (positive and negative affects, perception of gestation and implications of pregnancy) discussed as a group, since most of words were common. The study highlights shown how similar were the presented data by pregnant women surveyed. It is supposed about this fact the similarity is related to the social context. The relevance of this study for the health care network is to help with proposals aimed at specific improvements to the public and the sector, beside demonstrate that advanced age pregnant women and young adulst in the researched context showed no differences in the most of the studied characteristics

Comparação entre metodologias de extração de HPAs em água utilizando um planejamento fatorial com quantificação no CG/EM

PAHs (Polycyclic Aromatic Hydrocarbons) are a group of organic substances which receive considerable attention because of the carcinogenic and mutagenic properties of some of them. It is therefore important to determine the PAHs in different environmental matrices. Several studies have shown the use of gas chromatography coupled to mass spectrometry as a technique for quantification of PAHs by presenting excellent detection limits. This study aimed to develop an analytical methodology for the determination of 16 PAHs listed by the USEPA, test two methods for extraction of PAHs in water from a 23 factorial design, quantify them through the analytical technique coupled to gas chromatography mass spectrometry (GC/MS) using the method developed, and finally apply the results in chemometrics. The sample was synthesized and subjected to tests of the 23 factorial design, which has the factors: the type of extraction technique (ultrasound and digester), the ratio solvent / sample (1:1 and 1:3) and the type of solvent (dichloromethane / hexane and acetone / dichloromethane). The responses of eight combinations of the factorial design were obtained from the quantification by external calibration in GC/MS. The quantification method was developed from an optimized adaptation of the USEPA Method 8270. We used the full scan mode as a way of acquiring the mass spectra of 16 PAHs. The time in which the samples were subjected to ultrasound was fixed at 10 min and held an investigation to establish the conditions of power and time in the digester. We had the best response in the investigation of the digester power of 100 watts and the time of six minutes. The factorial design of liquid-liquid extraction showed that the most representative factors were: the use of the digester as extraction technique, the ratio solvent / sample 1:1 and the use of a 1:1 mixture of dichloromethane / hexane as a solvent more suitable. These results showed that the 1:1 mixture of dichloromethane / hexane is an excellent mixture to recover the extraction of PAHs an aqueous sample using the microwave digester. The optimization of the method of separation, identification and quantification of PAHs in the GC/MS was valid for 16 PAHs present in each chromatogram of the samples

O planejamento turístico e o comércio ambulante : uma análise à luz da teoria das representações sociais

The Social Representation Theory provides subsidies to scientifically analyze what is called common sense, suggesting that thought be given credibility to the individual, from the assignment of logic to it. The Representations allow us to interpret, understand, explain and thus classify information, events and people. In this sense, this study aimed to analyze how social representations of the actors of the intinerant traders who operate in Ponta Negra/RN can be used as an element for tourism planning. To achieve the desired goals, we conducted a qualitative study, from a descriptive study, using methods of data collection the research literature, the technique of free association of words and the questionnaire, applied with 90 intinerant traders who work in Ponta Negra/RN beach. As tools of data analysis were used to analyze literature, and software EVOC and SPHINX. This research has revealed the predominance of people in itinerant male, between 18 and 28 years, with incomplete primary education, no contributors of Previdência Social and working seven days a week. The core elements of representations brings that explain that their knowledge is guided by collectively shared knowledge in the culture of tourism, which is seen as something that brings economics benefits (money) to the society, from the travel and entertainment. The plan represents the forward thinking, based on development plans that seek improvements and organization. The structure and operation of tourism planning in Natal/RN, there were no representation of intinerant traders. It is concluded that understanding the needs of itinerant traders provides grants to developing strategies for the development of tourism. This is achieved from its inclusion in tourism planning, since it enables tourism managers to understand how they are capturing, interpreting and acting on their next reality, since these representations are fundamental in forming opinions and the establishment of individual attitudes and collective. Thus, it is an important theory to be used to subsidize social research with individuals living reality and local needs, but which is the margin of decision-making processes of economic in the Brazil