Uma fonte chaveada de 50kW com correção de fator de potência para alimentação de uma tocha de plasma Indutiva utilizando técnicas de controle digital

This work deals with the development of an experimental study on a power supply of high frequency that provides the toch plasmica to be implemented in PLASPETRO project, which consists of two static converters developed by using Insulated Gate Bipolar Transistor (IGBT). The drivers used to control these keys are triggered by Digital Signal Processor (DSP) through optical fibers to reduce problems with electromagnetic interference (EMI). The first stage consists of a pre-regulator in the form of an AC to DC converter with three-phase boost power factor correction which is the main theme of this work, while the second is the source of high frequency itself. A series-resonant inverter consists of four (4) cell inverters operating in a frequency around 115 kHz each one in soft switching mode, alternating itself to supply the load (plasma torch) an alternating current with a frequency of 450 kHz. The first stage has the function of providing the series-resonant inverter a DC voltage, with the value controlled from the power supply provided by the electrical system of the utility, and correct the power factor of the system as a whole. This level of DC bus voltage at the output of the first stage will be used to control the power transferred by the inverter to the load, and it may vary from 550 VDC to a maximum of 800 VDC. To control the voltage level of DC bus driver used a proportional integral (PI) controller and to achieve the unity power factor it was used two other proportional integral currents controllers. Computational simulations were performed to assist in sizing and forecasting performance. All the control and communications needed to stage supervisory were implemented on a DSP

Evolução de Rádio Fontes Duplas Extragalácticas

Double radio sources have been studied since the discovery of extragalactic radio sources in the decade of 1930. Since then, several numerical studies and analytical models have been proposed seeking a better understanding of the physical phenomena that determines the origin and evolution of such objects. In this thesis, we intended to study the evolution problem of the double radio sources in two fronts: in the ¯rst we have developed an analytical self-similar model that represents a generalization of most models found in the literature and solve some existent problems related to the jet head evolution. We deal with this problem using samples of hot spot sizes to ¯nd a power law relation between the jet head dimension and the source length. Using our model, we were able to draw the evolution curves of the double sources in a PD diagram for both compact sources (GPS and CSS) and extended sources of the 3CR catalogue. We have alson developed a computation tool that allows us to generate synthetic radio maps of the double sources. The objective is to determine the principal physical parameters of those objects by comparing synthetic and observed radio maps. In the second front, we used numeric simulations to study the interaction of the extra- galactic jets with the environment. We simulated situations where the jet propagates in a medium with high density contrast gas clouds capable to block the jet forward motion, forming the distorted structures observed in the morphology of real sources. We have also analyzed the situation in which the jet changes its propagation direction due to a change of the source main axis, creating the X-shaped sources. The comparison between our simulations and the real double radio sources, enable us to determine the values of the main physical parameters responsible for the distortions observed in those objects

Estudo da viabilidade do desenvolvimento de sistemas integrados baseados em redes em chip sem processadores: sistema IPNoSys

The increase of capacity to integrate transistors permitted to develop completed systems, with several components, in single chip, they are called SoC (System-on-Chip). However, the interconnection subsystem cans influence the scalability of SoCs, like buses, or can be an ad hoc solution, like bus hierarchy. Thus, the ideal interconnection subsystem to SoCs is the Network-on-Chip (NoC). The NoCs permit to use simultaneous point-to-point channels between components and they can be reused in other projects. However, the NoCs can raise the complexity of project, the area in chip and the dissipated power. Thus, it is necessary or to modify the way how to use them or to change the development paradigm. Thus, a system based on NoC is proposed, where the applications are described through packages and performed in each router between source and destination, without traditional processors. To perform applications, independent of number of instructions and of the NoC dimensions, it was developed the spiral complement algorithm, which finds other destination until all instructions has been performed. Therefore, the objective is to study the viability of development that system, denominated IPNoSys system. In this study, it was developed a tool in SystemC, using accurate cycle, to simulate the system that performs applications, which was implemented in a package description language, also developed to this study. Through the simulation tool, several result were obtained that could be used to evaluate the system performance. The methodology used to describe the application corresponds to transform the high level application in data-flow graph that become one or more packages. This methodology was used in three applications: a counter, DCT-2D and float add. The counter was used to evaluate a deadlock solution and to perform parallel application. The DCT was used to compare to STORM platform. Finally, the float add aimed to evaluate the efficiency of the software routine to perform a unimplemented hardware instruction. The results from simulation confirm the viability of development of IPNoSys system. They showed that is possible to perform application described in packages, sequentially or parallelly, without interruptions caused by deadlock, and also showed that the execution time of IPNoSys is more efficient than the STORM platform

Simulação de reservatórios de petróleo em ambiente MPSoC

The constant increase of complexity in computer applications demands the development of more powerful hardware support for them. With processor's operational frequency reaching its limit, the most viable solution is the use of parallelism. Based on parallelism techniques and the progressive growth in the capacity of transistors integration in a single chip is the concept of MPSoCs (Multi-Processor System-on-Chip). MPSoCs will eventually become a cheaper and faster alternative to supercomputers and clusters, and applications developed for these high performance systems will migrate to computers equipped with MP-SoCs containing dozens to hundreds of computation cores. In particular, applications in the area of oil and natural gas exploration are also characterized by the high processing capacity required and would benefit greatly from these high performance systems. This work intends to evaluate a traditional and complex application of the oil and gas industry known as reservoir simulation, developing a solution with integrated computational systems in a single chip, with hundreds of functional unities. For this, as the STORM (MPSoC Directory-Based Platform) platform already has a shared memory model, a new distributed memory model were developed. Also a message passing library has been developed folowing MPI standard