Filipe Carretas, J. F. Martins, V. Fernão Pires, A. J. Pires, Pedro M. Ramos, Fernando M. Janeiro
Squirrel cage induction motors are the most common electric machines employed in industrial environments. Periodic online condition monitoring should be performed for early electrical and mechanical fault detection, thus preventing further deterioration of the machine in case a fault is present. Motor current signature analysis is usually used for online fault detection and different algorithms that fall in this category have recently been proposed. In this paper, the spectrum of the RMS value of the stator current is used to detect the presence of rotor static eccentricity.
TC4 Symposium 2011
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Maik Rosenberger, Mathias Schellhorn, Patrick Werner, Andre Göpfert, Matthias Rückwardt, Gerhard Linss
The main focus in this paper lies on a novel interface design to transmit image data combined with results trough a single interface. Therefore the data stream is divided in two logical parts the image data and the result data. The big advantage is the transfer via different standardized interfaces like Universal Serial Bus (USB) or Gigabit-Ethernet (GigE) Vision. The transfer model was tested in a scalable hardware platform developed in previous work.
TC4 Symposium 2011
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Nikolas Libert, Leonardo Lipinski, Marco José da Silva
The correct measurement of gas-liquid two-phase flow is important in many industrial applications. In this paper, we describe the development and evaluation of a non-intrusive capacitive probe. Care was taken to allow for fast measurements (up to 5 kHz sampling rate). Two calibration procedures for void fraction measurement in annular and stratified flow are also described.
TC4 Symposium 2011
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Raquel A. A. Rodrigues, Glauco Fontgalland, Raimundo C. S. Freire
The goal of this paper is to plot the electromagnetic field behavior from multisources and calculate the density power inside a vehicle. It was done by measuring the electric field radiated by monopole antennas of λ/4, in frequency 2.045GHz. The Monopole antennas were positioned inside the vehicle to simulate the height of the mobile device in use by adults humans. The results show that the reflections of the microwave should be considered in risk assessments of EMF exposure in daily life.
TC4 Symposium 2011
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Helena Geirinhas Ramos, Artur Lopes Ribeiro, Dário Pasadas,Tiago Rocha
This paper presents a simple algorithm to model eddy current inspection when an uniform time-variable electric field in imposed in a region of a metallic plate sample with machined hole defects. The magnetic field perturbation due to a round hole defect subject to an unperturbed field is determined. The problem is formulated in terms of complex potentials and the method of conformal mapping is used to transform the domain with a round hole into a simpler domain in which the solution can be computed. To check the validity of this method the acquired voltage signals previewed with the...
TC4 Symposium 2011
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Senay Negusse, Peter Händel
In this paper, we consider a dual channel signal model with common frequency that is appropriate in a plurality of measurement setups, including impedance measurements and imbalance measurement in direct conversion RF receivers. We investigate on a new approach and present analysis of parameter estimation, specifically the seven parameter dual channel sine fit in which the signals from both channels are uniformly subsampled with coprime pair of sparse samplers and combined in a single array. Simulation results shall show acquired improvement in complexity as well as loss in estimation...
TC4 Symposium 2011
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A. Lopes Ribeiro, Helena G. Ramos, J. Couto Arez
This paper describes the implementation of a device that measures the thickness of metallic plates. A pancake coil for magnetic field sinusoidal excitation is used and detection is performed with a bridge giant magneto-resistor sensor. The paper uses the theory of the linear transformer to explain the liftoff effect with a special attention to the point of intersection phenomenon.
TC4 Symposium 2011
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Daniele Gallo, Carmine Landi, Mario Luiso
Since the penetration of photovoltaic (PV) systems in the electrical network is increasing, the need to register and model the contribution of these systems, in terms of disturbances and power availability, is becoming a crucial key for optimal management of grid. On the other hand, electrical signature of sources and loads is the unique generation/consumption pattern intrinsic to each individual electrical appliance/piece of equipment. So, this paper, starting from the analysis of the disturbance impact of a 20 kW grid connected PV system, performs a preliminary study on building a method...
TC4 Symposium 2011
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M. P. Almeida, R. P. David, R. S. Souza,P. V. G. Castellanos, J. C. Braz, M. V. Lima, F. F. Lima, L. Silva Mello
The Digital Radio Mondiale (DRM) system broadcasts audio in the frequency band below 174 MHz [1]. In this experiment, designed to evaluate the DRM system performance in urban areas in Brazil, a hybrid signal composed of an analog AM signal and a digital DRM signal, with the same content, were broadcasted in diurnal and nocturnal transmissions. This paper describes the experimental setup and presents initial results of medium wave propagation measurements campaigns that are being carried out in Brazil. The experiment is part of a series of field trials that are being conducted by the...
TC4 Symposium 2011
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R. M. Souza, R. V. F. Ventura, F. A. Silveira
As the national metrology institute of Brazil, Inmetro is responsible for the maintenance and support given to clients in Brazil and abroad. In order to implement its services with high quality performance, Inmetro develops systems which will provide the dissemination of the basic magnitudes. Corroborating to this mission, the Voltage and Current Laboratory (Latce) presents its standard for ac-dc current transfer based on Single Junction Thermal Converters (SJTCs), the behaviour of Latce’s standards, and the recent upgrades in the system. Responsible for the calibration of both voltage and...
TC4 Symposium 2011
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