Design and Optimization of Power Delivery and Distribution Systems Using Evolutionary Computation Techniques

Nowadays computing platforms consist of a very large number of components that require to be supplied with diferent voltage levels and power requirements. Even a very small platform, like a handheld computer, may contain more than twenty diferent loads and voltage regulators. The power delivery designers of these systems are required to provide, in a very short time, the right power architecture that optimizes the performance, meets electrical specifications plus cost and size targets. The appropriate selection of the architecture and converters directly defines the performance of a given solution. Therefore, the designer needs to be able to evaluate a significant number of options in order to know with good certainty whether the selected solutions meet the size, energy eficiency and cost targets. The design dificulties of selecting the right solution arise due to the wide range of power conversion products provided by diferent manufacturers. These products range from discrete components (to build converters) to complete power conversion modules that employ diferent manufacturing technologies. Consequently, in most cases it is not possible to analyze all the alternatives (combinations of power architectures and converters) that can be built. The designer has to select a limited number of converters in order to simplify the analysis. In this thesis, in order to overcome the mentioned dificulties, a new design methodology for power supply systems is proposed. This methodology integrates evolutionary computation techniques in order to make possible analyzing a large number of possibilities. This exhaustive analysis helps the designer to quickly define a set of feasible solutions and select the best trade-off in performance according to each application. The proposed approach consists of two key steps, one for the automatic generation of architectures and other for the optimized selection of components. In this thesis are detailed the implementation of these two steps. The usefulness of the methodology is corroborated by contrasting the results using real problems and experiments designed to test the limits of the algorithms

DC/DC Converter Parametric Models for System level Simulation

The objective of this work is to propose a whole solution for simulating power systems based on the use of behavioral DC/DC converter models. The proposed model is a generic model whose parameters can be obtained from data sheets (especially useful to model commercial converters) or equivalent tests. The model has configurable features which can be activated or disabled in order to perform optimal simulations or to generate models with different levels of abstraction to be used in a top-down design methodology

Modeling and Simulation Requirements for the Analysis and Design of DC Distributed Power Electronics Systems

The objective of this paper is to establish which are the requirements of the component models in a distributed power system in order to satisfy the necessities of the system architect. Based on the information that will help the designer to make the right decision for its architecture and the selection of their components, different levels of modeling will be required for each simulation. The paper also shows the implication of the modeling approach on the requirements for the simulator and the description language

A Parametrization Tool for Power Electronics Design at System Level

This paper describes a parameterization software used for the generation of behavioral models of power converters. This tool eases the capture and generation of fast and accurate models based on the information provided by manufacturers and measures. The models incorporate many behavioral features and can be used at different levels in the analysis, design and verification of complete power distribution systems like aircraft and automotive power systems. Simulations of common tests of power systems are presented to show the functionality of the models

Robustness Analysis of DC Distributed Power Systems by Means of Behavioral DC-DC Converter Models

The aim of this paper is to determine the model requirements for dc-dc converters in order to analyze and evaluate the performance of different architectures of DC distributed power systems and to assure that all the specifications are met under all parameter variations. Based on these requirements a parametric model for the dc-dc converters is presented that can be identified as a function of the information given by the manufacturers in their datasheets. In this way, it is possible to make sensitivity and worst case analysis that can help the designer to evaluate the robustness of their architectures

Top-down methodology employing hardware description languages (HDLs) for designing digital control in power converters

This paper presents a research line oriented to develop methodologies that takes advantage of hardware description languages in order to simplify the design of power converters that employ digital control techniques. The methodology focuses on setting the adequate communications among subsystems in order to simplify the change of the levels of abstraction of the subsystem’s models (from the conceptual level to the actual electric + synthesizable code). Changing the level of abstraction in the design process pretends: first to provide useful models at early designing steps; second, to optimize the simulation of the system, and at same time optimize the verification step

Fast architecture generation and evaluation techniques for the design of large power systems

This paper presents a methodology used to simplify the design of power supply systems based on high level of abstraction simulation models. This approach allows the designer to make decisions concerning the power system architecture and its components. This paper is focused on the techniques to identify topology candidates that can be built with available voltage regulator technologies and find the solution with best trade-off among energy efficiency, size and cost. In order to solve the problem when the number of possible options is very large, metaheuristic algorithms are used

Power Conversion Modeling Methodology Based on Building Block Models

Power systems modeling tools used to analyze static and dynamic characteristics usually rely on detailed and complex models, thus taking a long simulation time. Due to the acceleration of time to market of today's computing platforms, it is required to arrive at feasible solution options in a short amount of time to meet cost and time targets. Specifically, the areas of power conversion and power management traditionally rely on experimental verification and are lacking in computer design methodologies. In this paper, a modeling methodology based on fundamental building block models for power delivery systems is presented to address the aspects of energy efficiency optimization, area occupied by the power delivery solution and the cost associated with power conversion

New Control Strategy for Energy Conversion Based on Coupled Magnetic Structures

In this paper, a new strategy for energy conversion based on a coupled magnetic structure is presented. A proper control of the input voltages provides constant output voltage at any time and ideally no output filter is required and no energy is stored, enabling very fast dynamics and low losses in the converter since switching frequency can be very small. Ideal features and actual limitations of the proposed concept are analyzed. A prototype with a two-input magnetic structure is built in order to prove the concept

Genotoxicity and mutagenicity of Echinodorus macrophyllus (chapéu-de-couro) extracts

Echinodorus macrophyllus, commonly known as chapéu-de-couro, is a medicinal plant used in folk medicine to treat inflammation and rheumatic diseases. In this work, we used short-term bacterial assays based on the induction of SOS functions to examine the genotoxicity and mutagenicity of an aqueous extract of E. macrophyllus leaves. Whole extract and an ethyl acetate fraction showed similar genotoxicity and caused an ~70-fold increase in lysogenic induction. The extract also gave a positive result in the SOS chromotest with an increase of 12-fold in β-Galactosidase enzymatic units. There was a strong trend towards base substitutions and frameshifts at purine sites in the mutations induced by the extract in Escherichia coli (CC103 and CC104 strains) and Salmonella typhimurium test strains (22-fold increase in histidine revertants in TA98 strain). Since reactive oxygen species may be implicated in aging process and in degenerative diseases, we used antioxidant compounds as catalase, thiourea and dipyridyl in the lysogenic induction test. All this compounds were able to reduce the induction factor observed in the treatment with chapéu-de-couro, thus suggesting that the genotoxicity and mutagenicity were attributable to the production of reactive oxygen species that targeted DNA purines