Houston, TX, United States
Houston, TX, United States

Time filter

Source Type

Mansano R.K.,Integrated AV Systems | Godoy E.P.,Integrated AV Systems | Porto A.J.V.,University of Sao Paulo
Sensors (Switzerland) | Year: 2014

Recent advances in wireless networking technology and the proliferation of industrial wireless sensors have led to an increasing interest in using wireless networks for closed loop control. The main advantages of Wireless Networked Control Systems (WNCSs) are the reconfigurability, easy commissioning and the possibility of installation in places where cabling is impossible. Despite these advantages, there are two main problems which must be considered for practical implementations of WNCSs. One problem is the sampling period constraint of industrial wireless sensors. This problem is related to the energy cost of the wireless transmission, since the power supply is limited, which precludes the use of these sensors in several closed-loop controls. The other technological concern in WNCS is the energy efficiency of the devices. As the sensors are powered by batteries, the lowest possible consumption is required to extend battery lifetime. As a result, there is a compromise between the sensor sampling period, the sensor battery lifetime and the required control performance for the WNCS. This paper develops a model-based soft sensor to overcome these problems and enable practical implementations of WNCSs. The goal of the soft sensor is generating virtual data allowing an actuation on the process faster than the maximum sampling period available for the wireless sensor. Experimental results have shown the soft sensor is a solution to the sampling period constraint problem of wireless sensors in control applications, enabling the application of industrial wireless sensors in WNCSs. Additionally, our results demonstrated the soft sensor potential for implementing energy efficient WNCS through the battery saving of industrial wireless sensors. © 2014 by the authors; licensee MDPI, Basel, Switzerland..


De Andrade M.G.C.,Integrated AV Systems | Martino J.A.,University of Sao Paulo | Simoen E.,IMEC | Claeys C.,IMEC | Claeys C.,Catholic University of Leuven
Microelectronic Engineering | Year: 2015

In this paper, the low-frequency (LF) noise in standard n-channel triple-gate Bulk FinFETs has been experimentally investigated with variation in the fin widths (WFin), channel lengths (L) and gate dielectric. The origin of the noise will be analyzed in order to understand the physical mechanisms involved in 3D device architectures. Although the device scaling brings the idea of noise reduction, we show the opposite behavior because already single electron trapping has a marked impact on the device operation. Significant variation in the noise spectral density has been observed, which is related to the random occurrence of excess Lorentzian components (1/f2-like), associated with generation-recombination (GR) noise. In addition, the gate-voltage-dependent GR noise peaks have been studied, which are assigned to gate oxide traps. © 2015 Elsevier B.V.


Pradhan K.P.,National Institute of Technology Rourkela | Andrade M.G.C.,Integrated AV Systems | Sahu P.K.,National Institute of Technology Rourkela
Superlattices and Microstructures | Year: 2016

The symmetrical dual-k spacer technology in hybrid FinFETs has been widely explored for better electrostatic control of the fin-based devices in nanoscale region. Since, high-k tangible spacer materials are broadly became a matter of study due to their better immunity to the short channel effects (SCEs) in nano devices. However, the only cause that restricts the circuit designers from using high-k spacer is the unreasonable increasing fringing capacitances. This work quantitatively analyzed the benefits and drawbacks of considering two different dielectric spacer materials symmetrically in either sides of the channel for the hybrid device. From the demonstrated results, the inclusion of high-k spacer predicts an effective reduction in off-state leakage along with an improvement in drive current. However, these devices have paid the cost in terms of a high total gate-to-gate capacitance (C gg) that consequently results poor cutoff frequency (f T) and delay. © 2016 Elsevier Ltd.


Liberado E.V.,University of Campinas | Marafao F.P.,Integrated AV Systems | Simoes M.G.,Colorado School of Mines | Souza W.A.D.,University of Campinas | Pomilio J.A.,University of Campinas
Expert Systems with Applications | Year: 2015

In order to ensure good power quality for modern power systems and/or industrial installations, power conditioning devices have been extensively applied. However, the data analysis for the installation of a determined compensator mainly considers a particular power quality index or disturbance and it is usually based on human expertise. Therefore, this paper proposes a novel expert system that automatically suggests the most appropriate and cost-effective solution for compensating reactive, harmonic and unbalanced current through a careful analysis of several power quality indices and some grid characteristics. Such an expert system is an important tool in real-world applications, where there is a complex scenario in choosing, designing and applying power quality compensators in modern power grids. Since there are no strict boundaries for voltage and current non idealities at distribution level or clear correlation between them and possible solutions, a fuzzy decision-maker was developed to deal with such uncertainties and to embed human expertise in the system. The approach is based on analyzing data from a given time window and providing off-line recommendations for the design and installation of proper compensators. Therefore, the application of the proposed expert system may result in enhanced and faster projects when compared to the traditional design methods for power conditioning. A computational study consisting on applying the suggested compensators for a 5-node network and different load configurations shows the effectiveness of the proposed expert system. © 2014 Elsevier Ltd.


Moreira A.C.,University of Campinas | Paredes H.K.M.,Integrated AV Systems | Da Silva L.C.P.,University of Campinas
Electric Power Systems Research | Year: 2015

This article proposes the use of the conservative power theory as an alternative tool to analyze and determine the possible impacts of noisy loads on electrical distribution systems. The orthogonal decomposition of current (or power) of the conservative power theory allows the definition of different performance factors, each factor represents a specific feature of the load (current lag behind the voltage, unbalance and harmonic distortion). Each factor is used to identify potential effects of the X-ray machine on the system. Furthermore, a computational model developed in PSCAD/EMTDC of the three-phase X-ray machine is presented. The analysis and discussions are based on simulations and actual measurements obtained on the terminals of an X-ray machine. The presented results helps to demonstrate the main advantage of the CPT compared to conventional approaches, which is related to its general application for single phase and poly-phase circuits, for asymmetrical and distorted supply voltages, for nonlinear and unbalanced loads and, for variable line frequency. © 2015 Elsevier B.V. All rights reserved.


Marafao F.P.,Integrated AV Systems | Brandao D.I.,University of Campinas | Costabeber A.,University of Nottingham | Paredes H.K.M.,Integrated AV Systems
IET Renewable Power Generation | Year: 2015

ln recent years, the concept of decentralising power generation through the deployment of distributed generators (DGs) has been widely accepted and applied, driven by the growing market of renewable energy sources. These DGs are normally equipped with a switching power interface, acting as front end with the grid. This paper proposes a multi-task control strategy for distributed generation systems that simultaneously allows the DG to inject the available energy, as well as to work as a voltage drop compensator or as an active power filter, mitigating load current disturbances and improving power quality of the grid. The main contribution of the proposed system, with respect to other solutions in the literature, is that the proposed control loops are based on the Conservative Power Theory decompositions. This choice provides decoupled power and current references for the inverter control, offering a very flexible, selective and powerful control strategy for the DG. The paper also discusses the choice of the current waveform for injecting/absorbing active power into/from the grid, and both sinusoidal and resistive references have been compared in terms of damping capability. Finally, simulation and experimental results are provided in order to validate the proposed functionalities of the DG control system. © The Institution of Engineering and Technology 2015.


Brandao D.I.,University of Campinas | Paredes H.K.M.,Integrated AV Systems | Costabeber A.,University of Nottingham | Marafao F.P.,Integrated AV Systems
IET Power Electronics | Year: 2016

This study proposes a flexible active power filter (APF) controller operating selectively to satisfy a set of desired load performance indices defined at the source side. The definition of such indices, and of the corresponding current references, is based on the orthogonal instantaneous current decomposition and conformity factors provided by the conservative power theory. This flexible approach can be applied to single- or three-phase APFs or other grid-tied converters, as those interfacing distributed generators in smart grids. The current controller is based on a modified hybrid P-type iterative learning controller which has shown good steady-state and dynamic performances. To validate the proposed approach, a three-phase four-wire APF connected to a non-linear and unbalanced load has been considered. Experimental results have been generated under ideal and non-ideal voltage sources, showing the effectiveness of the proposed flexible compensation scheme, even for weak grid scenarios. © The Institution of Engineering and Technology 2016.


Liberado E.V.,University of Campinas | de Souza W.A.,University of Campinas | Pomilio J.A.,University of Campinas | Paredes H.K.M.,Integrated AV Systems | Marafao F.P.,Integrated AV Systems
Przeglad Elektrotechniczny | Year: 2013

This paper describes a methodology to design Static var Compensators (SVC) using the reactive energy definition from the Conservative Power Theory. The application of this methodology is presented through simulations of local and distributed compensation scenarios. Results show effective compensation of reactive current and load unbalance. Moreover, the harmonic distortion caused by thyristor controlled reactor has been suitable attenuated by passive filters designed in combination with the SVC.


Marafao F.P.,Integrated AV Systems | Souza W.A.,University of Campinas | Liberado E.V.,University of Campinas | da Silva L.C.P.,University of Campinas | Paredes H.K.M.,Integrated AV Systems
Przeglad Elektrotechniczny | Year: 2013

This paper deals with the analysis and application of novel conformity factors, defined by means of the Conservative Power Theory (CPT), for the purpose of load analysis and characterization. Basically, such factors are able to describe the influence of different load characteristic on the power factor calculation and they are valid under generic load and supply voltage conditions. Moreover, the development of a flexible smart-meter prototype has been described and used to the experimental validation of all power components and conformity factors considered on the paper.


Loading Integrated AV Systems collaborators
Loading Integrated AV Systems collaborators