A5034276144- High voltage insulation and dielectric phenomena
- Power Transformer Diagnostics and Insulation
- Electrostatic Discharge in Electronics
- Tailings Management and Properties
- Medical Imaging Techniques and Applications
- Advanced X-ray and CT Imaging
- Advanced Fiber Optic Sensors
- Dam Engineering and Safety
- Electrical and Bioimpedance Tomography
- Minerals Flotation and Separation Techniques
- Welding Techniques and Residual Stresses
- Metal and Thin Film Mechanics
- Mine drainage and remediation techniques
- Soil Geostatistics and Mapping
- Soil Management and Crop Yield
- Geography and Environmental Studies
- Semiconductor Lasers and Optical Devices
- Orthopaedic implants and arthroplasty
- Thermography and Photoacoustic Techniques
- Magnetic Field Sensors Techniques
- Groundwater flow and contamination studies
- Thermal Analysis in Power Transmission
- Magneto-Optical Properties and Applications
- Experimental and Theoretical Physics Studies
- Electrical and Thermal Properties of Materials
Institutos Lactec
2002-2022
Universidade Federal do Paraná
2002-2022
Abstract The aim of this work was to investigate the mechanical properties titanium anodic films (TiO 2 ) produced by oxidation under galvanostatic conditions, using a 1.4 M phosphoric acid electrolyte, with different current densities ( J on commercially pure (cp‐Ti). morphology oxide were observed scanning electron microscopy (SEM), whereas composition film determined Raman spectroscopy. Porosity, average roughness (Ra) and thickness TiO increased applied . Hardness elastic modulus...
The electrical tracking that occurs in polymeric materials used as insulators is an undesired phenomenon. We developed a method to quantify the amount of energy dissipated during occurrence surface discharges based on standard IEC 60112. uses wave form factor voltage sample main parameter determine integration period instantaneous power. function time shows linear behavior, and after certain period, change slope this curve (mean power) indicates new stage degradation process.
The ampacity of a material is defined as its maximum electrical current capacity. In an overhead transmission line, it related to the sag that does not compromise safe operation. As depends on conductor's temperature, with this parameter possible estimate ampacity, increasing efficiency system via real‐time energy dispatch management. With Brillouin backscattering phenomena, distributed temperature measurement in fibre inside optical ground wire (OPGW) or phase conductor possible. However,...
In power distribution networks, polymer insulators commonly show flaws in their interior which cannot be perceived without the use of a non-destructive inspection mechanism. This work describes methodology based on three-dimensional industrial computer tomography (CT) for automatic detection insulators. CT slices were reconstructed using 180 digital radiographs (projections) acquired by high-resolution system (pixel dimension 50 μm x μm). For reconstruction 3D CT, μm-wide bitmap used....
A nondestructive testing technique for imaging of voids and inclusions in dielectric materials high-voltage application is described. Void partial discharge occurrence induced by a narrow pulsed x-ray beam scanning the bulk epoxy sample. Phase resolved analysis recorded as function position. The data matrix used to construct digital gray scale images, which gives information about location, dimensions, activity each defect materials. This can be an important tool evaluate degradation state material.
Various apparatus for x and (gamma) -ray computed tomography (CT) have been constructed by us during the last 20 years, with aim of producing simple low-cost systems nondestructive testing. The first one was in 1980 used an Am<SUP>241</SUP> radioactive source emitting 59.6 keV -rays a single NaI(Tl)-x ray detector. Successively, substituted years x-ray tubes, detector multi- detection system such as arrays detectors image intensifiers. CT-scanner employs 160 kV tube 6' X intensifier coupled...
High-density polyethylene (HDPE) has many applications, including in the electrical sector, due to its excellent electrical, mechanical, and thermal properties. In insulators employed electricity networks, material is exposed various adverse conditions (solar radiation, humidity, temperature cycles, pollution), which can accelerate degradation of polymer, modifying properties affecting performance field. The surface resistivity HDPE hinders transmission current on surface, consequently...
Guaricana hydroelectric power plant concrete dam, located in the South of Brazil, was investigated after 49 years operation. A part mortar altered to ettringite, and other by-products. The inner defects fracture polished sample surfaces were detected by CT SEM. samples extracted from two parts dam top valley. Elemental chemical composition phases determined EDS XRD analysis. reservoir water showed that it less aggressive structure. Percolated analyses revealed a mortar-mass loss 3 kg/year....
Ampacity is defined as the maximum current carrying capacity of an electrical conductor without compromising its physical integrity. A possible methodology for monitoring this parameter in transmission lines consists distribution punctual temperature sensors along line. This paper presents development electronic instrumentation a and equipment to be applied 230 kV power lines. The chosen transducer Rogowski Coil because linear response decoupling between measurement circuits, while NTC...
A preliminary study of induced partial discharge behavior in epoxy samples by continuous and pulsed X-ray is described. Phase resolved analysis recorded as a function beam intensity trigger angle. It shown that the amplitude distributions applied voltage phase angle proportional to intensity. For probability range larger occurrence between 60 78 degrees.
O objetivo deste trabalho é mostrar como o uso de um software adequado permite resolver problema do efeito Kelvin maneira simples em condutores cilíndricos. Calculamos a forma onda da corrente elétrica para tensões aplicadas não senoidais, tópico este importância eletrônica alta freqüência.