ELEMENTS ON NUMERICAL AND EXPERIMENTAL STUDY OF POWER BUS MANUFACTURED IN COPPER LAMINATES

This paper presents elements on numerical and experimental study of power buses manufactured on copper laminates aiming to assist electronic projects development which may use printed circuit board, also contributing to improve layouts, manufacturing processes and production costs reduction. The quantitative approach was used in bibliographical, documentary and a prototype was developed for this purpose. The results obtained from the tests suggest that the type of material proposed in this study, when subjected to an intense electric current flow presents performance suiting the intended purpose. In conclusion, we assume that the use of copper laminates in the manufacture of power buses allows the development of new configurations in electrical and / or electronic projects which leads to the manufacture process of assembly be similar to the world-wide trend

Petri Nets Applied in Purge Algorithm Analysis for a Rocket Engine Test with Liquid Propellant

During the development stage of a space vehicle, instrumented tests are carried out on the ground to prove the operational capacity of each liquid-propellant rocket engine, which is installed in this type of vehicle. The task of elaborating a Test Bench project for a propulsion unit with this application is complex and involves several steps, one of these steps being related to the analysis of this bench capacity to meet the algorithms for the liquid-propellant rocket-engine full run of tests, which is considered fundamental for this project’s operational success. Due to the high costs involved in this project’s elaboration and execution, it is strategic to use computational resources to evaluate, by simulation, the main operational functionalities that are previously established for this bench to perform. In this context, this work presents a model proposal through Petri Nets to evaluate, by computer simulation, an architecture capacity that was designed for the Test Bench to meet an algorithm dedicated to the liquid-propellant pipelines purge during the run of hot tests with the liquid-propellant rocket engine. The method used in this work to carry out the simulation shows the operational response of each module of this architecture, in accordance with the steps contained in the purge algorithm, which allows for analyzing, for each event of the process, the Petri Nets properties, mainly those related to the conservativeness, liveliness, deadlock-type, and confusion-type conflicts. The simulation carried out with the proposed model allows for the portrayal of the physical architecture and the operational states of the purge system according to the steps foreseen in the algorithm, showing that the conservation property is met because the number of marks remains constant, the vivacity property is also met since all positions have been reached, and there is no mortal-type conflict, as the simulation is not stopped; only confusion-type conflict is identified, which was solved with the strategic insertion of resources in the model in order to fix crashes related to the competition for tokens in the transition-enabled entries. The satisfactory results obtained in these simulations suggest that the modules provided for this architecture are sufficient and appropriate for carrying out all the steps contained in the purge algorithm, which will minimize or even eliminate the disorders that may be caused by the presence of foreign elements in the propellant supply lines during the tests with the rocket engine

Automation proposal applied to Trolleybus current collector

This work presents the main steps performed in the development of a system proposal to automate the operation of the current collector that is used in trolleybuses, aiming, mainly, to continuously monitor the contact with the overhead electric wire and also to provide the coordinated movement of collection in situations of circuit disconnection, in order to reduce the incident of collisions between the collector and the mechanical structure of this wire. These improvements are aimed at contributing to the quality of the public transport service, a factor that corroborates the expansion of new routes of mass public transport that use renewable sources of energy, replacing the traditional vehicles powered by combustion with fossil fuel. The method employed and the details contained in this proposal allow the use of an expressive o part of the traditional design of the current collector, being suggested the substitution of parts, adequacy of the mechanical structure related to the fixation points of the components, installation of sensor elements, actuating elements, and programmable controller with dedicated algorithm for this application. The positive results observed in the computational evaluations of the electronic and pneumatic circuit, which are managed by a dedicated control algorithm for these systems, suggest that the resources and components proposed in this work when effectively integrated in trolleybuses will be able to meet the purposes for which they are intended

Arquitetura dedicada para realizar testes operacionais em módulos fotovoltaicos

A atual situação estabelecida pela escassez de recursos naturais não renováveis para a geração de energia, associada com a tendência mundial em buscar o desenvolvimento sustentável, impulsionaram a ascensão e busca por fontes e recursos energéticos alternativos. Alinhada com essa tendência se destaca a energia solar, a qual é produzida a partir da radiação solar e caracterizada como uma fonte profusa, renovável, sustentável e limpa. Essa pode ser utilizada em processo térmico para aquecimento e/ou em sistema do tipo solar fotovoltaico para geração de eletricidade. Decorrente das vantagens que estão relacionadas com a utilização desses sistemas é possível expandir as aplicações nos diversos segmentos da sociedade, sendo que a implantação de sistema para gerar eletricidade com o uso dessa tecnologia requer a instalação de um ou mais arranjos de módulos fotovoltaicos. Durante a fase de instalação em campo, esses módulos podem ser submetidos aos diferentes tipos de solicitações mecânicas, as quais possuem o potencial e a capacidade de causar desconformidades no seu funcionamento, estabelecendo uma situação na qual é necessário realizar retrabalhos, o que impacta em custo, tempo e qualidade. Para minimizar as consequências dessas desconformidades, testes operacionais podem ser realizados nesses módulos antes de sua instalação em campo, a fim de verificar a integridade dos mesmos. Nesse contexto, este trabalho propõe uma arquitetura para sistema realizar automaticamente os testes operacionais em módulos fotovoltaicos antes da fase de instalação em campo. A validação dessa arquitetura é realizada por meio de testes práticos em protótipo desenvolvido para esse fim. Os resultados obtidos nesses testes foram positivos, sugerindo que a arquitetura proposta é adequada para a finalidade a qual se destina