A não linearidade entre a reação de quem copia e de quem é copiado

This article offers an account of experiences related to the problem of third-party copyright infringement, as well as some measures adopted by Coppe (the Alberto Luiz Coimbra Institute for Graduate Studies and Research in Engineering, at Rio de Janeiro Federal University) to curb potential problems in this area, including formal and educational measures. The title suggests that the issue is still poorly understood among undergraduate and graduate students (and professors), and that a wholly nonlinear reaction is common between those who copy or those who are copied. We end the article with some suggestions on measures that could be adopted to eliminate (minimize) problems of plagiarism and raise awareness on matters of integrity in research.Este artigo apresenta um relato de experiências relacionadas ao problema de violação de direitos autorais de terceiros, bem como algumas medidas adotadas pela Coppe da Universidade Federal do Rio de Janeiro, de forma a coibir possíveis problemas nessa área, incluindo medidas formais e educativas. O título sugere que o tema ainda é pouco esclarecido entre os alunos (e professores) de graduação e pós-graduação, sendo comum a reação totalmente não linear entre quem copia ou quem é copiado. Conclui-se o trabalho com algumas sugestões sobre medidas a serem adotadas para se eliminar (minimizar) problemas de plágios e conscientizar dos problemas de integridade na pesquisa

A Computational Approach to Optimal Damping Controller Design for a GCSC

This paper presents a computational approach for an offline measurement-based design of an optimal damping controller using adaptive critics for a new type of flexible ac transmission system device-the gate-controlled series capacitor (GCSC). Remote measurements are provided to the controller to damp out system modes. The optimal controller is developed based on the heuristic dynamic programming (HDP) approach. Three multilayer-perceptron neural networks are used in the design-the identifier/model network to identify the dynamics of the power system, the critic network to evaluate the performance of the damping controller, and the controller network to provide optimal damping. This measurement-based technique provides an alternative to the classical linear model-based optimal control design. The eigenvalue analysis of the closed-loop system is performed with time-domain responses using the Prony method. An analysis of the simulation results shows potential of the HDP-based optimal damping controller on a GCSC for enhancing the stability of the power system

Analysis of integrated STATCOM-SMES based on three-phase three-level multi-pulse voltage source inverter for high power utility applications

This paper is aimed to investigate the operating characteristics of a static synchronous compensator (STATCOM) integrated with superconducting magnetic energy storage (SMES) for high power applications in the transmission network level. The STATCOM controller topology comprises multi-level multi-pulse neutral-point clamped-type (NPC) voltage source inverters (VSIs) using the harmonics cancellation technique, and incorporates a SMES coil. An innovative two-quadrant multi-level dcdc converter is proposed to effectively interface the STATCOM with the superconducting coil using a buck-boost topology with neutral point voltage control capabilities; thus enabling to simultaneously control both active and reactive power exchange with the high voltage power system. A detailed analysis of major system variables is presented, including analytical results and digital simulations using the MATLAB/Simulink environment. Moreover, a three-level control scheme is designed, including a full decoupled current control strategy in the dq reference frame with a novel controller to prevent the STATCOM dc bus capacitors voltage drift/imbalance and an enhanced power system frequency controller.Fil: Molina, Marcelo Gustavo. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Mercado, Pedro Enrique. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan; ArgentinaFil: Watanabe, Edson H.. Universidad Nacional de San Juan. Facultad de Ingeniería. Instituto de Energía Eléctrica; Argentin

Selective active filter applied to an arc furnace adjusted to harmonic emission limitations

This paper describes how to calculate the dif-ferent harmonic sequences that should be filtered with ashunt selective active filter, for two control alternatives: load current measurement or line current measurement. These results are then generalized for shunt hybrid selective filters. Passive parameters are chosen considering the resonances with the electric system that appear. Design basis are defined in order to obtain a minimum cost filter which also meet the applicable regulations requirements. Finally, results showing the potentiality of the selective filter controlled for the proposed methods are reported

Selective active filter with remote harmonic distortion control

PostprintThis paper presents the calculation methods for the different filtering blocks of a selective active filter in order to minimize the active filter inverter size, keeping the harmonic emissions at the limits stated by the applicable regulations. Since it may be necessary to comply with the regulations at a remote place with respect to the active filter location, the method has been extended to this case. In order to validate the simulations, measurements which were made at a real application - and arc furnace - were used. Finally, the simulated results obtained with a remote hybrid filter were compared with those obtained when an active filter is installed directly at the place where the harmonic emission regulations must be met. The comparison shows that remote compensation is an alternative to be seriously considered. The results are similar to those obtained with local compensation and the cost may be substantially lower

Optimal Dynamic Neurocontrol of a Gate-Controlled Series Capacitor in a Multi-Machine Power System

This paper presents the design of an optimal dynamic neurocontroller for a new type of FACTS device - the gate controlled series capacitor (GCSC) incorporated in a multi-machine power system. The optimal neurocontroller is developed based on the heuristic dynamic programming (HDP) approach. In addition, a dynamic identifier/model and controller structure using the recurrent neural network trained with backpropagation through time (BPTT) is employed. Simulation results are presented to show the effectiveness of the dynamic neurocontroller and its performance is compared with that of the conventional PI controller under small and large disturbances

Filtro activo de mínimo costo ajustado a la carga de un horno de arco y a las reglamentaciones sobre emisión armónica aplicables

En este trabajo se presenta una forma de diseñar un filtro activo shunt utilizando la teoría de la potencia activa y reactiva instantánea adaptándose a la reglamentación aplicable en cuanto a límites de emisión armónica permitida. Se analiza la Reglamentación Argentina, se compara con las recomendaciones de la IEEE, se modela la carga típica con la que debería lidiar el filtro, que en nuestro caso es un horno de arco industrial. Luego analiza aspectos del diseño del filtro pasa altos interno del filtro activo que separa que frecuencias de la corriente se eliminan y cuales no. Finalmente se llega a valores característicos constructivas del filtro activo como ser tensiones nominales, su capacitor en el bus de continua y corrientes máximas por las llaves

Study of a simplified model for DFIG-based wind turbines

In the study of the dynamical behavior of doublyfed induction generators (DFIG), for wind power applications, the use of reduced order models is useful in order to design specific control strategies for wind power plants as well as to obtain lightweight computing simulations. Within this field this paper presents a new dynamic model for wind turbines, based on DFIG, able of representing accurately its behavior during both the steady state and the transient of the grid voltage. As it will be proven this model permits to perform an accurate analysis of the system when there is a voltage dip in the grid. In the following a theoretical study of this model will be carried out and the accuracy of its performance will be tested under different conditions, by means of PSCAD/EMTDC simulations, in order to show its reliability. Finally the reliability of the simplified model will be tested in a scaled experimental setup.Peer ReviewedPostprint (published version

Control of DFIG-WT under unbalanced grid voltage conditions

The voltage oriented control in the synchronous reference frame (VOC-SRF) have been extensively used for controlling wind turbines based on doubly fed induction generators (DFIG-WTs) through the rotor side converter of a back to back power processor. Although its performance is fast and accurate under balanced conditions its behaviour is not good enough when the voltage of the mains is unbalanced, unless an independent control for the positive and the negative sequence is implemented. This paper proposes a new control system able to control the DFIG-WT under unbalanced conditions using a simple algorithm, which does not need to be implemented for both symmetrical components but on the static αβ reference frame. The reliability of the presented system will be tested by means of PSCAD simulations under balanced and unbalanced grid conditions.Peer ReviewedPostprint (published version

Measurement of the production of a W boson in association with a charm quark in pp collisions at √s = 7 TeV with the ATLAS detector

The production of a W boson in association with a single charm quark is studied using 4.6 fb−1 of pp collision data at s√ = 7 TeV collected with the ATLAS detector at the Large Hadron Collider. In events in which a W boson decays to an electron or muon, the charm quark is tagged either by its semileptonic decay to a muon or by the presence of a charmed meson. The integrated and differential cross sections as a function of the pseudorapidity of the lepton from the W-boson decay are measured. Results are compared to the predictions of next-to-leading-order QCD calculations obtained from various parton distribution function parameterisations. The ratio of the strange-to-down sea-quark distributions is determined to be 0.96+0.26−0.30 at Q 2 = 1.9 GeV2, which supports the hypothesis of an SU(3)-symmetric composition of the light-quark sea. Additionally, the cross-section ratio σ(W + +c¯¯)/σ(W − + c) is compared to the predictions obtained using parton distribution function parameterisations with different assumptions about the s−s¯¯¯ quark asymmetry