Elektro Electricity and Services
Elektro Electricity and Services
Ribeiro S.,Brazilian Center for Research and Development in Telecommunications |
Suiama D.,Elektro Electricity and Services
Communications in Computer and Information Science | Year: 2011
This paper presents a method able to identify and analyze authentication mechanisms for a given type of application. Currently, there are several applications that use and require a mechanism to provide the user with physical or logical access. This article proposes a solution developed by Fundação CPqD that identifies which mechanism is more suitable and recommended for a given type of application, considering the restrictions and challenges for every type of mechanism. Finally, a case study will be exposed providing an example of authentication mechanism analysis and identification system. © 2011 Springer-Verlag.
Bhatt P.,Brazilian Center for Research and Development in Telecommunications |
Capovilla J.,Brazilian Center for Research and Development in Telecommunications |
De Souza J.,Brazilian Center for Research and Development in Telecommunications |
Resende J.,Elektro Electricity and Services |
And 2 more authors.
ACM International Conference Proceeding Series | Year: 2014
With the increase in popularity of smart devices for metering purposes, the concerns and the scope of the threats also gets bigger. In order to raise awareness and provide a simulated environment for information security training to smart meter manufacturers, we developed MeterGoat, which is a flexible framework for smart meter penetration testing. In this research paper, we describe the implementation of MeterGoat and present some sample lessons that explore vulnerabilities based on weak anti-tampering techniques, flawed authentication, and improper use of cryptography. Copyright 2014 ACM 978-1-4503-3033-6/14/09...$15.00.
Xavier S.S.,Elektro Electricity and Services |
Lima J.W.M.,Federal University of Itajubá |
Lima L.M.M.,Federal University of Itajubá |
Lopes A.L.M.,University of Minas Gerais
Journal of Control, Automation and Electrical Systems | Year: 2015
During the last years, the electricity sector has experienced great changes, especially within the economic regulation. After receiving several criticisms, the rate of return regulation has been replaced by incentive regulation. The main objective of this regulation is to stimulate business efficiency. This paper proposes an alternative application of data envelopment analysis to the Brazilian case, characterized by a large territory: the use of Unit Networks in the distribution segment to regionalize the concession area and then to analyse the efficiencies separately. Many regulators use the entire distribution company as a decision-making unit for price regulation when benchmarking is applied. However, in Brazil, quality performance is measured in detail using sets of consuming units, i.e. quality is measured using small parts of the company. Given that efficiency cannot be assessed without considering various aspects of quality performance and characteristics of the underlying environment in the utility’s concession area, this paper tries to find the trade-off between management, quality, environment and costs. Therefore, the main contribution of this paper is twofold: the solution for Brazilian distribution companies’ heterogeneity and the choice of variables that are better measures for an efficiency analysis. Some examples with Brazilian utilities are provided to show the advantages of the proposed approach. © 2015, Brazilian Society for Automatics--SBA.
Madeiro S.,University of Campinas |
Galvao E.,Elektro Electricity and Services |
Cavellucci C.,University of Campinas |
Lyra C.,University of Campinas |
Von Zuben F.,University of Campinas
2011 IEEE Congress of Evolutionary Computation, CEC 2011 | Year: 2011
There are two common strategies for technical loss reduction in electric power distribution networks: (a) the installation of capacitor banks to compensate the losses produced by reactive currents; and (b) the redefinition of the topology of electric distribution networks by changing the state of some sectionalizing switches to balance the load. Both strategies can be formulated as combinatorial optimization problems. The optimization problems for the first and the second strategies are usually known as Capacitor Placement Problem (CPP) and Network Reconfiguration Problem (NRP), respectively. In this paper, we propose a new approach based on Genetic Algorithm (GA) to solve both CPP and NRP simultaneously. The new approach makes use of two previously proposed and independent techniques for the CPP and the NRP. The performance of the new approach is compared with the performance of the two previously proposed techniques applied in a separate manner. The experiments show that the new method is more efficient regarding the metrics of power loss reduction and voltage profile enhancement. © 2011 IEEE.
Corton M.L.,University of South Florida |
Zimmermann A.,Elektro Electricity and Services |
Phillips M.A.,University of Florida
Energy Policy | Year: 2016
We analyze the impact of introducing output-based incentives in the price-cap regulatory regime of the Brazilian electricity distribution sector. We focus on the trade-off between operating costs and quality improvement, hypothesizing a positive relationship. Operating costs include maintenance and repair expenses. The regulator sets limits for service continuity and non-technical energy losses in each regulatory period. Service continuity refers to the average length of interruptions in electricity distribution. Non-technical losses refer to losses due to factors specific to the distribution segment. Quality incentives include peer-pressure and penalties/rewards for compliance with minimum quality standards. We model operating costs using a GMM framework to acknowledge endogeneity of variables. The model is dynamic given the inclusion of regulatory lags to recognize past cost behavior. Findings reveal a small trade-off between costs and quality. We conclude that quality improvements are not costly relative to the potential savings from complying with quality standards. We also find that the impact on operating costs is larger when energy losses increase compared to the cost effect due to increases in duration of outages. These findings suggest areas of attention in managerial decision making, and serve as valuable information to the regulator in tailoring quality incentives for this sector. © 2016 Elsevier Ltd
E Silva L.S.C.,Federal University of Goais |
De Seixas F.J.M.,São Paulo State University |
Dionizio P.,São Paulo State University |
Joao C.P.,São Paulo State University |
And 2 more authors.
2015 IEEE 13th Brazilian Power Electronics Conference and 1st Southern Power Electronics Conference, COBEP/SPEC 2016 | Year: 2015
The objective of this work is to present a generalized analysis of power quality of the Thyristor Controlled Series Compensator for electrical distribution systems application (D-TCSC). The studies include normalized graphics that indicate the harmonic behavior and the possibilities of parallel resonance of D-TCSC. The main simulation results show the improvement of the voltage load and confirm the behavior of the normalized graphics that are presented in comparative Tables. © 2015 IEEE.
Coralli A.,EnergiaH |
Coralli A.,Federal University of Rio de Janeiro |
Villela De Miranda H.,EnergiaH |
Espiuca Monteiro C.F.,EnergiaH |
And 2 more authors.
Journal of Power Sources | Year: 2014
Solid oxide fuel cells are globally recognized as a very promising technology in the area of highly efficient electricity generation with a low environmental impact. This technology can be advantageously implemented in many situations in Brazil and it is well suited to the use of ethanol as a primary energy source, an important feature given the highly developed Brazilian ethanol industry. In this perspective, a simplified mathematical model is developed for a fuel cell and its balance of plant, in order to identify the optimal system structure and the most convenient values for the operational parameters, with the aim of maximizing the global electric efficiency. In this way it is discovered the best operational configuration for the desired application, which is the distributed generation in the concession area of the electricity distribution company Elektro. The data regarding this configuration are required for the continuation of the research project, i.e. the development of a prototype, a cost analysis of the developed system and a detailed perspective of the market opportunities in Brazil. © 2014 Elsevier B.V. All rights reserved.
Wilhelm H.,Diagno Materiais |
Feitosa L.,Diagno Materiais |
Silva L.,Diagno Materiais |
Cabrino A.,Elektro Electricity and Services |
Ramos L.,Federal University of Paraná
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2015
The Rancimat method was used to evaluate the consumption of antioxidant additive in a natural ester insulating fluid (NEI). NEI samples were aged in the laboratory with and without oxygen bubbling. NEI samples were also collected from a transformer in operation. Samples of NEI (unused, aged in the laboratory and collected from transformer in operation) were analyzed by Fourier-transform infrared spectroscopy (FTIR) and by the Rancimat method for induction time (IT) measurement. The results showed that it is possible to evaluate the consumption of antioxidant additive in NEI in service by the Rancimat method. Laboratory tests were also performed to extend the lifetime of NEI in service by adding new loads of antioxidant additive. The results showed that the addition of new antioxidant additive loads when the IT of in-service NEI (determined by Rancimat method) reaches about 3 h extends the lifetime of this oil. © 1994-2012 IEEE.
Gutnik Y.,University of Sao Paulo |
Altafim R.A.P.,University of Sao Paulo |
Veronese P.R.,University of Sao Paulo |
Resende J.F.,Elektro Electricity and Services |
And 3 more authors.
Annual Report - Conference on Electrical Insulation and Dielectric Phenomena, CEIDP | Year: 2012
Piezoelectrets from thin electrically charged cellular polypropylene-foam films have been suggested for numerous transducer applications, such as force sensors for keyboards, flat microphones for conference environments, or devices for ultrasound generation and detection. In addition to polypropylene piezoelectrets, other materials systems - such as thermo-fused polymer-film stacks - were developed in order to generate piezoelectrets that are thermally more stable and contain geometrically well-controlled air cavities. Here, we demonstrate the viability of the recently developed piezoelectret systems that had been prepared by thermo-lamination with templates for the acoustical detection of electric discharges in air. Furthermore, we show that the resonance behavior of the air cavity in which the electric discharge occurs can also be assessed from the acoustic signal. For the experiments, a transducer prototype with a preamplifier directly connected to the laminated piezoelectret sensor inside an electrically shielded package was developed. Reproducible sound measurements according to the ASTM E976-10 standard were performed with the transducer prototype. The prototype was later employed in acoustical measurements of electric discharges in an air gap inside an acoustical chamber - in order to reduce external noise - and in a metallic chamber for reducing electrical interference. The recorded signals were compared by means of Fast-Fourier-Transform (FFT) analysis. © 2012 IEEE.
Flauzino R.,University of Sao Paulo |
Da Silva I.N.,University of Sao Paulo |
Spatti D.,University of Sao Paulo |
Silva J.F.R.,Elektro Electricity and Services |
And 2 more authors.
2015 IEEE PES Innovative Smart Grid Technologies Latin America, ISGT LATAM 2015 | Year: 2015
Smart Cities are the new goal for Smart Grid applications. In this context it can highlighted several researches introducing modern concepts of projecting, modelling, and simulating. This paper presents a new approach for fault diagnoses in distribution feeders inserted into a Smart City. The ability to handle load variations, several kind of permanent or temporary faults and non-linearities are performed by a hybrid combination of Fuzzy Systems and Orthogonal Decomposition. Results are shown to validate the approach. © 2015 IEEE.