Aplicação da logística reversa como solução para gestão dos resíduos eletrônicos

The present study aimed to analyze how develops the reverse logistics process applied in electrical and electronic products. Such analysis was obtained through literature search and with the completion of a case study, which was developed at the company's Oxil Reverse Manufacture, showing the advantages obtained as well as the difficulties faced in the implementation of the reverse logistics process. The development of this research shows its importance in so far as the residues generated by electronic components, which are one of the most harmful to the environment and harmful to human health, highly possessing heavy metals and non-biodegradable materials in their composition. In this way, the components collected from this activity, should be properly recycled, reused and finally housed in suitable location, these steps that are part of the reverse logistics process

Um estudo de novos paradigmas na realização de projetos de instalação elétrica residencial (automação)

Through awareness of new trends of consumption of the population with regard to housing, comfort, entertainment, security and sustainability, it was crafted a work that set out to study and develop the concept of home automation and how it will revolutionize the electrical installation projects and energy savings. A pre-wiring project, taking into account, basically, the installed load, is presented as a basis for comparison. The protocols for communication between intelligent devices in an automation environment, used in the work, are the X-10, LonWorks and UPnP. The home network is studied and divided into subsystems, for a better understanding, which are the lighting, audio, video and multimedia system, security, air conditioning and central vacuum system, and the idea of integrated design and system integrator is introduced, showing the change necessity in the design philosophy of electrical installations. The main means of energy savings in an automated home, such as dimerization, master off and smart meters are presented and, finally, it was concluded that there is a need to structure electrical installation projects more comprehensive with regard to home automation, in order to become more efficient and useful to users

Controle de velocidade e tração de rodas independentes para veículos elétricos

This work presents a proposal to replace thetraditional system of traction electric car that usesone electric motor and a mechanical differential, by two electric motors of lower power, controlled byelectronic control low cost. The proposed control isopen loop and uses the technique of Pulse WidthModulation (PWM), discrete and synchronizedaiming to reduce the generation of harmonics. The implementation of two smaller motor one on each wheel-drive distributes the weight of the vehicle, improving the heat exchange of the windings,beyond enable the power components supporting a current of 50% predicted for only one motor . The solution adopted for being open-loop, has a similar behavior to the mechanical differential, where theeffort imposed by the trajectory makes the velocity distribution between the wheels be appropriate tovehicle trajectory

Análise do consumo de energia elétrica e da eficiência energética em uma indústria de processamento de madeira

In the industries of wood processing (sawmills), where timber is sawn in equipment such as band saws, circular saws, trowel, thicknessers, among others, that mechanically transform this resource and use of electric motors, which are not unusually poorly scaled working or overloaded, often a factor that is not found in these industries and has fundamental importance in the production process is energy efficiency that is achieved by both technological innovation and through all the practices and policies that aim to lower energy consumption, lowering energy costs and increasing the amount of energy offered no change in generation. For both during the design of an electrical installation, both overall and in various sectors of the installation, investigations are necessary, considerations and uses of variables and factors that put into practice the theme of energy efficiency. Therefore, in this paper, these factors were calculated and analyzed for a wood processing industry (sawmill) in the municipality of Taquarivaí - SP, namely: active power, power factor, demand factor and load factor. Where they were small in relation to the literature, these events that occur when devices are connected at the same time and due to the conditions of processing the wood, where the engines have large variations in electricity consumption during the unfolding of the same, due to efforts with the load and idle moments between each machining operation in the equipment

O uso de software para estudo de seletividade e coordenação

The present work aims to prepare a study of selectivity and coordination in an isolated electrical system with the aid of computer software PTW (Power Tools for Windows). Based on appropriate protection standards, on equipment data and the survey of the curves of “time versus current” (Time Current Curve – TCC), may be defined protection settings to leave the system selective, coordinated and properly protected. Definitions of adjustments are made taking into account the data of, so called, thermal curves of the equipment, which take into account the rated current and the supportability of short-circuit current of the equipment and cables involved in the installation in question. For that we use the tools provided by the PTW in which an industrial electrical circuit is simulated, presenting and discussing the results. With that validates the software PTW, taking it as a great tool helper implementation the coordination and selectivity study

Desenvolvimento de um smart meter: um estudo sobre eficiência energética através das redes inteligentes

Pós-graduação em Engenharia Elétrica - FEB

Localização de descargas parciais em transformadores de potência imersos em óleo mineral por meio de cápsulas piezelétricas de baixo custo e sistemas inteligentes

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Controlador PID utilizando microcontrolador PIC

This monograph proposes the implementation of a low cost PID controller utilizing a PIC microcontroller, and its application in a positioning system previously controlled by a dedicated integrated circuit for a positioning system. Applying the closed-loop PID control, the system instability was reduced, and its response was smoother, eliminating vibrations and mechanical wear compared to its response with the dedicated integrated circuit, which has a very limited control action. The actuator of the system is a DC motor, whose speed is controlled by the Pulse Width Modulation (PWM) technique, using a Full-Bridge circuit, allowing the shift of direction of rotation. The utilized microcontroller was the PIC16F684, which has an enhanced PWM module, with its analog converters used as reference and position feedback. The positioning sensor is a multiturn potentiometer coupled to the motor axis by gears. The possibility of programming the PID coefficients in the microcontroller, as well as the adjustment of the sampling rate, allows the implemented system achieving high level of versatility

Estudo para correção dos sensores da rede de monitoramento do campo elétrico em função do campo elétrico de tempo bom

A monitoring network of atmospheric electric field covering the Vale do Paraiba region was implemented. The sensors were located on different sites with different altitude and geographic topology. The present work reports the study carried on those sensors in order to verify the necessity of using some correction factor to the measured local electric field intensity due to effects of local environment. The measurements were done in continuous 24 hours per day with the data recorded on registers in each device accumulating information during a period of four months. The relation between the electric field values by each sensor was compared to the reference located on Sao Jose dos Campos city using the same period. In a graphical analysis using the local field intensity and the reference, the data were fitted to a straight line obtained by minimum square method. Variation up to 95% was observed between the field values in some sensors. Another method was proposed, comparing the mean values of the electric field in a function of time. The variation in some sensors reached up to 133%. We conclude that the variations are due to local atmospheric conditions and no correction factor is required on the electric field sensors

Sistema de automação residencial controlado via rede doméstica

The present work develops a residential automation system controlled by PIC microcontroller connected to a domestic network using the TCP/IP protocol. This was motivated by the viability of building an automation system to control basic elements of a house with low cost, which cannot be found nowadays. Initially is presented a brief history of the automation systems and an introduction about PIC microcontrollers. Afterwards is presented an overview of the system to be implemented. Then it is shown a suggested circuit and the sensor and actuator elements as well as the software to manage the system, this was all build and test in the laboratory. In the end are the results obtained from the prototype, like the energy consumption, the cost, efficiency and reliability

Elementos de manutenção de transformadores de potência

The intended purpose of this paper is to present the main commissioning tests for power transformers and the most used techniques in industrial segment, it is also discussed your results and consequences in the equipment’s normal operation. Also in this text, it is given specific information concerning a maintenance plan compatible to power transformers, with elements of preventive and predictive maintenance, exposing essential components, tests and the regulations current, showing how analyze and interpreted the results from this maintenance resources. Also in this paper is submitted the economic impact of damage to transformers and how the correct maintenance method can minimize them. The objective of this text is demonstrate the importance of the equipment and the benefits of proper maintenance, much of in financial terms as in electric system reliability

Aplicação do conceito de geração distribuída a um sistema fotovoltaico residencial

This work presents a study about distributed generation using photovoltaic systems in the context of smart grids. The characteristics of a Smart Grid and the several aspects this concept involves - distributed generation among them - are discussed. There are also examples of equipment, like smart meters, and of national and international projects. The specificities of distributed generation and the rules and standards necessary in this sort of installation are talked through with focus in the solar energy generation method. Regarding photovoltaic systems, the working principles of the panels are presented, along with its main electrical characteristics and the technologies available. Finally there is a study concerning the sizing of a distributed generation system that involves photovoltaic panels in a residential plant. An analysis of the costs and return of investment period is made about the specific case in consideration.

Controle fuzzy de um motor dc utilizando sistema de aquisição de dados e o matlab

The present work develops a fuzzy inference system to control the rotation speed of a DC motor available in Degem Kit. Therefore, it should use the fuzzy toolbox of Matlab in conjunction with the data acquisition board NI - USB - 6009, a National Instrument’s board. An introduction to fuzzy logic, the mathematical model of a DC motor and the operation of data acquisition board is presented first. Followed by the controller fuzzy model implemented using Simulink which is described in detail. Finally, the prototype is shown and the simulator results are presented

Proposta de uma metodologia de rebobinamento para converter motor de indução trifásico em monofásico

This paper proposes the conversion of a three-phase induction motor into single phase through rewinding its stator. It presents a methodology to calculate this rewinding process considering the constructive parameters of the, such as number of slots and number of poles, for instance. The operating principles of DC motors are highlighted to introduce the logic involved in the calculation of lap and wave windings. The construction of the stator three-phase induction motor generally uses the lap winding, which is also used in single phase to perform the conversion. The rewinding process is widely used for reconstruction of industrial and residential electric motors that have suffered damage or present flaws with use. Therefore, many three-phase electric motors that are discarded or disposed of could be recovered by the method described in this work for a purpose that contributes to energy efficiency or simply saving resources in single-phase uses

Chaveamento de cargas intermitentes usando sensor de corrente

Due to concerns about rational use of energy, several alternative technologies of power generation appeared, including the conversion of solar energy into electrical energy by photovoltaic panels. In low-income households, the refrigerator represents considerable impact on the electric bill, since it requires constant power given its use in food preservation. It is possible to reduce this share, with the use of an alternative energy source. This work presents a timed switching electronic system, which allows commercial equipment that is not affected by short interruptions in the power supply to use a photovoltaic panel as a source of alternative energy, which usually do not provide energy continuously. Switching is made automatically in case of low incidence of sunlight, and without any form of energy storage. Between each switching, there is a dead time without power supply, therefore preventing the use of synchronizers circuits between the photovoltaic panel and the public power grid. A circuit containing a 80C31 microcontroller is used to control the system’s switching. The photovoltaic panel’s voltage inverter is in H bridge configuration, and is also controlled by the microcontroller through Pulse Width Modulation, which makes use of preprogrammed tables to generate the control signals of the power transistors. Through the use of software simulations, the proposed system was tested, which is capable of supplying intermittent single-phase loads. The simulations indicates that the project developed in this paper can be assembled into a prototype and be tested under real operating conditions, as long as the scaling of components, the characteristics of the photovoltaic panel to be used, and the project involved load are taken into account