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Andriolo R.F.,Federal University of Parana | Fernandes T.S.P.,Federal University of Parana | Bessa M.R.,Federal University of Parana | Bloot M.L.,Companhia Paranaense de Energia
Journal of Control, Automation and Electrical Systems | Year: 2015

The operation planning of the Brazilian power system is a great challenge due to its size of continental dimensions, large seasonal variations, and predominantly hydroelectric nature. Its operation requires careful planning to reconcile conflicting goals such as spill minimization during the rainy season, and minimization of generation deficits during the dry season, i.e., operation risk minimization. The optimization models for hydrothermal systems currently used to operate large systems do not include the electric network when determining the energy goals. This work aims at modeling a hydrothermal dispatch problem by means of genetic algorithms. The electrical constraints are included by an optimal power flow, which is solved monthly over the planning horizon. The fitness function is composed of criteria that look for using the reservoirs as much as possible during the rainy season, thus, minimizing spills and production costs and, at the same time, catering for the load and limits of energy exchange between the subsystems. The methodology was tested using the 33-bus system. © 2015, Brazilian Society for Automatics--SBA. Source


Wilhelm H.M.,Diagno Materiais e Meio Ambiente | Franch V.,LACTEC Institute of Technology for Development | Tulio L.,LACTEC Institute of Technology for Development | Franch A.F.,Companhia Paranaense de Energia
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2015

The main objective of this study was to evaluate the effect of transformer construction materials, such as kraft insulation paper, varnish, core steel and gasket materials (rubber), on the physicochemical properties of natural ester-based insulating oils (NEIs) and mineral insulating oil (MIO) under heating. We evaluated two NEIs, one formulated with soya oil (Envirotemp FR3) and other with corn oil (Biovolt A). The test specimens were placed in a 1-L jar with 800 mL of insulating oil and then the jar was placed in an oven at 100 °C for 716 h. The insulating fluids were analyzed before and after the heating tests by physicochemical analyses, such as kinematic viscosity, acid number (or neutralization number), dissipation factor and interfacial tension for MIO. Properties of the aged reference and the test specimen oils for a standard testing method for compatibility of construction materials with NEIs are proposed. The only parameter that showed variation after the NEI compatibility testing with different materials was the dissipation factor at 90 °C. The results show that besides compatibility and aging tests, mechanical tests for the gasket or seal materials should also be performed to conclude whether a material is suitable for construction of transformers insulated with NEIs. © 1994-2012 IEEE. Source


Dos Santos I.,Federal University of Parana | Andriolo M.V.,Companhia Paranaense de Energia | Gibertoni R.C.,Institute Tecnologia para o Desenvolvimento | Kobiyama M.,Federal University of Santa Catarina
IAHS-AISH Publication | Year: 2010

The SWAT model was used to simulate the production and transport of water and sediment (suspended and bedload) in the Apucaraninha River watershed (504 km2), southern Brazil. The model was calibrated with daily discharge and sediment transport data, obtained during the period 1988-2005. The model simulation showed a good fit for both discharge and sediment transport when compared to observed values. Using the calibrated SWAT model, the impacts of different land-use and soil management activities on discharge and sediment transport were evaluated under the following scenarios: (1) the present condition without soil conservation practice; (2) the present condition with full riparian vegetation; (3) agriculture with soil conservation practice and full riparian vegetation; (4) 100% forest; (5) agriculture without soil conservation practice and with full riparian vegetation; (6) 100% agriculture without soil conservation practice; and (7) 100% agriculture with soil conservation practice. The mean values of total discharge between the various scenarios had a very small coefficient of variation (1%), while the mean values of surface runoff had a larger value (25%). For sediment transport, the difference between the scenarios was more significant. Compared with the current condition, scenario (4) resulted in a decrease of sediment transport of 89%, while scenario (6) resulted in an increase of 142%. Copyright © 2010 IAHS Press. Source


Pereira J.A.,Companhia Paranaense de Energia | Junior O.C.,Pontifical Catholic University of Parana
Applied Mechanics and Materials | Year: 2014

This paper, through a wide approach of Product Development Process (PDP) renowned methodologies, proposes a conceptual model to serve as a guide in the elaboration, management and implementation of research and development (R&D) projects classified by the R&D Program of Brazilian Electricity Sector which is regulated by the Brazilian Electricity Regulatory Agency (ANEEL). Product development methodologies can be applied to narrow the relationship between academy and industry ensuring results directed to the product, with reduction of costs and development time better suited to the customers needs, fulfilling integrally, at the same time, the Innovation Chain proposed by ANEEL R&D Program in the achievement of new technologies for the electricity sector. © (2014) Trans Tech Publications, Switzerland. Source


Wilhelm H.M.,LACTEC Institute of Technology for Development | Stocco G.B.,LACTEC Institute of Technology for Development | Batista Jr. S.G.,Companhia Paranaense de Energia
IEEE Transactions on Dielectrics and Electrical Insulation | Year: 2013

The degradation of in-service natural ester-based insulating fluid could result in oil viscosity, acidity and dissipation factor increases. In this work, natural ester-based insulating fluid samples aged in the laboratory and in-service (collected from a Recloser) were reclaimed with different adsorbent materials. All the tested samples showed some properties above the provisional limit for triggering prompt additional investigation suggested by the IEEE guide for in-service natural ester fluids, such as viscosity increase > 10% from value at time of initial energization, acid number > 0.3 mg KOH/g or dissipation factor at 25 0C > 3%. The reclamation process was accomplished by the use of two methods: 1) by mechanical agitation of the aged oil in the presence of several adsorbents and 2) by percolation of the aged oil through the adsorbent material. The reclaimed fluids were monitored by evaluation of viscosity, acid number and dissipation factor and the results were compared with unused oil. The results showed that viscosity is the main criterion to evaluate whether or not in-service natural ester-based insulating fluid can be reclaimed. © 1994-2012 IEEE. Source

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