2008
Authors
Fidalgo, JN;
Publication
PROCEEDINGS OF THE 7TH WSEAS INTERNATIONAL CONFERENCE ON COMPUTATIONAL INTELLIGENCE, MAN-MACHINE SYSTEMS AND CYBERNETICS (CIMMACS '08)
Abstract
Loads estimation is becoming each time more fundamental for an efficient management and planning of electric distribution systems. Among the factors that contribute to this need of more efficiency are the increasing complexity of these networks, the deregulation process and the competition in an open energy market, and environment preservation requirements. However, the only information generally available at MV and LV levels is essentially of commercial nature, i.e., monthly energy consumption, hired power contracts and activity codes. In consequence, distribution utilities face the problem of estimating load diagrams to be used in planning and operation studies. The typical procedure uses measurements in typical classes of consumers defined by experts to construct inference engines that, most of the times, only estimate peak loads. In this paper, the definition of classes was performed by clustering the collected load diagrams. Artificial Neural Networks (ANN) were then used for load Curve estimation. This article describes the adopted methodology and presents some representative results. Performance attained is discussed as well as a method to achieve confidence intervals of the main predicted diagrams.
2008
Authors
Carpaneto, E; Chicco, G; Sumaili Akilimali, J;
Publication
Electric Power Systems Research
Abstract
In the restructured electricity industry, meaningful loss allocation methods are required in order to send correct signals to the market taking into account the location and characteristics of loads and generations, including the local sources forming the distributed generation (DG). This paper addresses the issues related to loss allocation in radial distribution systems with DG, with a three-fold focus. First, the key differences in the formulation of the loss allocation problem for radial distribution systems with respect to transmission systems are discussed, specifying the modeling and computational issues concerning the treatment of the slack node in radial distribution systems. Then, the characteristics of derivative-based and circuit-based loss allocation techniques are presented and compared, illustrating the arrangements used for adapting the various techniques to be applied to radial distribution systems with DG. Finally, the effects of introducing voltage-controllable local generation on the calculation of the loss allocation coefficients are discussed, proposing the adoption of a "reduced" representation of the system capable of taking into proper account the characteristics of the nodes containing voltage-controllable DG units. Numerical results are provided to show the time evolution of the loss allocation coefficients for distribution systems with variable load and local generation patterns.
2008
Authors
Saeed, S; Harinarayanan, EV; Sinha, D; Ferreira, A;
Publication
Audio Engineering Society - 124th Audio Engineering Society Convention 2008
Abstract
We recently introduced a novel Automatic Noise Reduction (ANR) algorithm for the removal of wideband stationary/non-stationary noise from audio [1]. Current noise reduction techniques exhibit certain undesirable characteristics. Distortion and/or alteration of the audio characteristics is a common problem. User intervention in identifying the noise profile is sometimes necessary. ANR uses a novel framework employing dominant component subtraction and restoration and performs better than conventional techniques in subjective tests. Here we describe three enhancements to ANR. The first of these increases the level of noise removal for the special case of stationary background noise. The second is a new tool for improving the temporal envelope coherence and yields additional noise removal. The third is a multi-band processing tool for conditioning time-frequency envelope for reduced listener fatigue.
2008
Authors
Luo, Q; Salgado, HM; Pereira, JR;
Publication
2008 IEEE ANTENNAS AND PROPAGATION SOCIETY INTERNATIONAL SYMPOSIUM, VOLS 1-9
Abstract
This paper proposes a new low profile dual band WLAN Planar inverted-F antenna (PIFA) by using Electromagnetic Band-Gap (EBG) material as ground plane. The total thickness of this antenna is only 4 mm, which is half of the height when a normal perfect electric conductor (PEC) ground plane is used. The backward radiation ratio is also reduced as the existence of EBG. Moreover, the bandwidth for the 5 GHz; band is increased by 10 times compared to the reference antenna. This EBG PIFA is built on the ground plane with size of 40x62 mm, which is suitable for most of the mobile devices.
2008
Authors
Prado, AG; Bolzon, LB; Pedroso, CP; Moura, AO; Costa, LL;
Publication
Applied Catalysis B: Environmental
Abstract
2008
Authors
Carpaneto, E; Chicco, G; Sumaili Akilimali, J;
Publication
IEEE Transactions on Power Systems
Abstract
In this paper, the concepts related to loss partitioning among the phase currents in three-phase distribution systems are revisited in the light of new findings identified by the authors. In particular, the presence of a paradox in the classical loss partitioning approach, based on the use of the phase-by-phase difference between the input and output complex power, is highlighted. The conditions for performing effective loss partitioning without the occurrence of the paradox are thus established. The corresponding results are then used to extend the branch current decomposition loss allocation method for enabling its application to three-phase unbalanced distribution systems with distributed generation. Several numerical examples on a three-phase line with grounded neutral and on the modified IEEE 13-node test system are provided to assist the illustration and discussion of the novel conceptual framework. © 2008 IEEE.
The access to the final selection minute is only available to applicants.
Please check the confirmation e-mail of your application to obtain the access code.