José Vicente Canto dos Santos

New genetic algorithms for contingencies selection in the static security analysis of electric power systems

Two genetic algorithms designed for real time security analysis are presented.Only the static aspect of the security analysis was considered.Satisfactory results were obtained for test systems and large real life systems. The importance of a reliable supply of electric power in industrial society is unquestionable. In control centers of electrical utilities, an important task is the security analysis, even for those companies that already have the modern smart grids. In this task, a contingency is the operation outage of one or more devices, while contingencies selection is the determination of the most severe contingencies on the system. Despite the current technological advances, an analysis of all possible contingencies is impracticable. In this paper, a method to efficiently perform the selection of multiple contingencies is presented. The issue is modeled as a combinatorial optimization problem and solved by genetic algorithms, developed for this application. A robust method, which considers power flow and voltage, is presented and tested over IEEE-30 test system and over a large real life system, considering double outages of branches. The results showed accuracy close to 100%, when compared with an exact method.

Payback analysis in identification and monitoring of commercial losses in distribution networks

Commercial losses, or non-technical losses, represent a significant portion of the unbilled energy for power utilities. As an example, in Brazil, illegal connections in distribution networks are responsible for economic losses of about US

Um método para auxiliar processos de restauração de sistemas de potência

4.6 billion per year. Nowadays, advances in smart grids create a propitious scenario for the use of Intelligent Electronic Devices (IEDs) to design an application that solves this kind of problem. This paper presents a prototype of a low cost power meter for identification of commercial losses in distribution networks. This device uses IED concepts, with data communication to a central processing and analysis system. To demonstrate the applicability in power utilities, it is presented an economic viability and expected payback analysis of the proposed solution. This payback is calculated based on the IEDs costs and expected billing from the illegal connections detected. The developed prototype is under tests and preliminary results are described in the paper.

Real-Time Hand Prosthesis Biomimetic Movement Based on Electromyography Sensory Signals Treatment and Sensors Fusion

The subject of this work is the power system restoration, one of the main problems in the electrical engineering area. Due to the great dependency of electricity of a modern industrial society, this subject has receiving great attention. The restoration of large electrical power systems after the occurrence of serious blackouts is a complex problem where the basic goal is to obtain the system configuration in order to attend loads with different priorities. The restoration is done through stages and in each stage the service is restored to a predetermined set of loads. A method to solve important aspects of the power system restoration problem is presented in this work. The solution takes into account the nonlinear network model (AC model) as well as its constraints and operational limits. The fictitious network concept is extended to the reactive model, linear programming, a new model for the linearized power flow and conventional load flow calculation are used. Results obtained with a test system as well as with a large realistic Brazilian system are presented.

An Investigation to Identify Factors that Lead to Delay in Healthcare Reimbursement Process: A Brazilian case

The hand of the human being is a very sophisticated and useful instrument, being essential for all types of tasks, from delicate manipulations and of high precision, to tasks that require a lot of force. For a long time researchers have been studying the biomechanics of the human hand, to reproduce it in robotic hands to be used as a prosthesis in humans, in the replacement of limbs lost or used in robots. In this study, we present the implementation (electronics project, acquisition, treatment, processing and control) of different sensors in the control of prostheses. The sensors studied and implemented are: inertial, electromyography (EMG), force and slip. The tests showed reasonable results due to sliding and dropping of some objects. These sensors will be used in a more complex system that will approach the fusion of sensors through Artificial Neural Networks (ANNs) and new tests should be performed for different scenarios.

An analysis of the performance of power circuit breakers using a non-invasive system

Abstract Healthcare reimbursement has had a tremendous impact on healthcare institutions and the economy. The healthcare reimbursement process consists of coding, billing, and payment based on the care provided to the patient. The rapid development of new medical treatments and procedures and changes in regulations and policies have been increasing the complexity of the reimbursement process, resulting in financial, operational, and care delivery issues for healthcare institutions. Therefore, methods of process analysis, such as process mining, have been used as a basic strategy to improve the organizational effectiveness of healthcare institutions. In this context, the main objective of this study is to propose an approach to investigate the factors that may cause delays in the reimbursement process using a combination of process mining and data mining techniques to extract information from the process data and support decision-making. To accomplish this analysis, process mining is applied to map the reimbursement process from the event log and to determine possible bottlenecks. In contrast, data mining is used to identify frequent patterns and interesting associations in the process data. Finally, by applying the proposed approach to a real case of a healthcare institution in Brazil, we extracted valuable insights regarding process execution and confirmed the effectiveness and potential of combining process mining and the association rules mining techniques.

Radiometric monitoring applied in the evaluation performance of power circuit breakers

Some researches have shown that arcing produces impulsive radio-frequency radiation and through timing analysis of the received and recorded impulses, the switching times of circuit breakers can be measured and utilized in order to ensure the safe operation and reliability of these equipments. In this context, this paper presents a performance evaluation of power circuit breakers (CBs) using an antennas-based system along with signal processing techniques. The signals obtained from the arc created during the switching process are captured by the antennas and then processed aiming to characterize the operation process of the CB. Results of this analysis are shown for field measurements performed on CBs attached to shunt reactor of a substation in the southern Brazil.

Metaheurística Guia para Alocação Ótima de Sistemas de Medição Centralizados em Smart Grid

This paper presents an evaluation of the performance of power circuit breakers (CBs) using direct digital sampling and the signal processing techniques applied to antenna signals obtained from the arc created during the switching process. Some researches have shown that arcing produces impulsive radio-frequency radiation. Therefore, from timing analysis of the received and recorded impulses, the switching times of circuit breakers can be measured and utilized in order to ensure the safe operation and reliability of these equipments. Results of this analysis are shown for field measurements realized on CBs attached to capacitor banks and shunt reactors of substations of CEEE-GT, in southern Brazil.

Cell formation problem: An multithreading Tabu search for setup time optimization for limited machine magazines: A New Solution For A Classical Problem

Resumo—Sistemas de medição centralizados (SMC) de energia são atualmente uma escolha para automatizar redes e garantir o funcionamento do complexo sistema de distribuidoras de energia elétrica. Estes sistemas compõem as chamadas smart grids, redes inteligentes de geração, transmissão e distribuição, dotadas de dispositivos de comunicação de dados, possibilitando a aplicação de sistemas distribuídos, com base na troca de informações entre equipamentos, formando uma nova rede, também de alta complexidade, para interligação e controle. A utilização de infraestruturas avançadas de medição, baseada em SMC, alocadas em áreas de grandes concentrações urbanas, com objetivos de diminuição ou até mesmo eliminação de perdas comerciais de distribuição de energia, emerge como novidade na aplicação de redes inteligentes de distribuição de energia elétrica no país. Este trabalho descreve o desenvolvimento de uma solução computacional, baseada em um método de busca metaheurística conhecido como Simulating Annealing, guiada por outras heurísticas e formulada como um problema de recobrimento, para apoio à concepção de projetos de redes otimizadas de infraestrutura avançada de medição que utilizam equipamentos em uma rede de distribuição de energia elétrica, garantindo máxima cobertura da rede, atendimento a todos os clientes geograficamente localizados na região de projeto, minimizando custos de instalação dos sistemas. A estratégia apresenta bons resultados na formação de topologias de redes de comunicação para sistemas de medição centralizada e na otimização da utilização de equipamentos, reduzindo custos de instalação na rede. Palavras chave — Metaheurísticas, Simulated Annealing, Smart Grids, Distribuição de Energia Elétrica.

Animating complex articulated robots without a rigid hierarchy of transformations

This paper aims to present a solution for the Manufacturing Cell Formation Problem through the use of a multithreading Tabu Search that uses deterministic methods to effectively explore local optimum areas. Manufacturing Cell Formation problem involves the process of analysing parts and groups them according to their similarity. This paper aims maximize the production efficiency, by minimizing the machine setup time in a limited magazine size through the reduction of tool changes by creating clusters of parts that share machining tools and present an initial scheduling based on tool changes reduction. In order to valid the proposed algorithm, the results obtained are compared against other Tabu Search solutions proposed in the literature.