Search results for "signal processing"
showing 10 items of 2451 documents
Efficient CAD of Optimal Multi-Port Junctions Loaded with Partial-Height Cylindrical Posts using the 3D BI-RME Method
2005
A rigorous full-wave technique based on the 3D BI-RME (Boundary Integral-Resonant Mode Expansion) method for the analysis and design of compensated waveguide junctions is presented. This method is used to investigate the electrical performance of right-angled bends and rectangular waveguide T-junctions loaded with partial-height cylindrical posts, with the aim of extending the typical usable bandwidths of such components. It is found that the electrical performance of a two-way power divider can be significantly improved by considering a post displaced along the symmetry plane of the structure. Therefore, this contribution reveals a new crucial design parameter not considered in previous wo…
A low-cost compact uniplanar Quasi–Yagi printed antenna
2008
A low cost directive uniplanar broadband printed Quasi–Yagi antenna design is presented. As a particular realization, some prototypes have been designed to operate in the 2.45 GHz band. They have been then modeled, fabricated onto standard printed circuit dielectric substrate and tested successfully. For the design and the modeling processes, we have make use of FDTD based in-house developed algorithms. The obtained bandwidth is, for all the considered cases, better than 15%. The main radiation characteristics are 2–5.5 dBi gain, depending on the number of director elements, and better than 25 dB front-to-back ratio. Overall antenna size was, in any case lesser than 1 λ × 0.5 λ. © 2008 Wile…
Design and experimental verification of a smart sensor to measure the energy and power consumption in a one-phase AC line
2009
Abstract A mixed electronic system has been designed to measure the active, apparent and reactive energies delivered to a load in a single-phase AC voltage line. For this purpose a smart sensor (ADE7753 from Analog Devices) was used. A magnetoresistance sensor is used as a current transducer and it is constant current biased by a generalized impedance converter. The magnetoresistance sensor technology provides direct isolation from the mains voltage and ferrite cores are not needed like Hall counterparts. All the measurements provided by the ADE7753 are read through the parallel port of the computer using a LabView application, which will process and present the readings to the user.
A computer‐aided instrument for pattern recognition of partial discharges
1998
In this paper a new computer‐aided digital system for partial discharge (PD) measurements is presented. The system is able to collect a great number of data, up to a pulse repetition rate of 100kHz, during the acquisition phase, thus allowing an off‐line analysis of PD data. After a description of the instrument, some experimental tests performed on epoxy specimens are here presented in terms of amplitude, phase and energy resolved histograms. Finally, emphasis is given to the very interesting use of the instrument for pattern recognition techniques in the discrimination and classification of discharges in HV components.
Two Methods to Broaden the Bandwidth of a Nonlinear Piezoelectric Bimorph Power Harvester
2017
We propose two methods to broaden the operation bandwidth of a nonlinear pinned–pinned piezoelectric bimorph power harvester. The energy-scavenging structure consists of a properly poled and electroded flexible bimorph with a metallic layer in the middle, and is subjected to flexural vibration. Nonlinear effects at large deformations near resonance are considered by taking the in-plane extension of the bimorph into account. The resulting output powers are multivalued and exhibit jump phenomena. Two methods to broaden the operation bandwidth are proposed: The first method is to extend the operation frequency to the left single-valued region through optimal design. The second method is to exc…
Fuzzy control for Electric Power Steering System with assist motor current input constraints
2015
Abstract Friction and disturbances of the road are the main sources of nonlinearity in the Electric Power Steering (EPS) System. Consequently, conventional linear controllers design based on a simplified linear model of the EPS system will result in poor dynamic performance or system instability. On the other hand, a brush-type DC motor is more used in EPS control with an input current that is limited in practice. The control laws designed without taking into account the saturation effect may have undesirable consequences on the system stability. In this paper, a Takagi–Sugeno (T−S) fuzzy is used to represent the nonlinear behavior of an EPS system, and stabilization conditions for nonlinea…
Energy efficient operation in smart grids: optimal management of shiftable loads and storage systems
2012
In this paper, the authors analyze the impact of the participation of customers to the sustainable implementation of energy rational strategies in microgrids. The management of shiftable loads is compared to the control of real and reactive storage systems in smart grids. An optimization algorithm is used as analysis tool to assess the impact of such control variables in different conditions. The results clearly indicate that if shiftable loads are of suitable size, they have a more promising as tools to both reduce losses and to flatten the peak load through the HV/MV bus. Many tests have been carried out on a real experimental MV system in the area of Rome Italy.
Energy Harvesting-Aware Backoff Algorithms for Distributed Device-to-Device Communication
2016
Due to limited energy capacity in mobile devices, energy harvesting is regarded as a promising technology for lifetime extension in device-to-device (D2D) communication. However, medium access control (MAC) protocols designed for D2D communication intrinsically do not consider the existence of harvested energy. In this paper we study four backoff (BO) algorithms, among which one algorithm is proposed to enhance the BO selection based on energy harvesting rate and residual energy of devices. Simulations are performed in order to assess how the proposed algorithm can extend the lifetime of a D2D communication network as well as to provide fair channel access opportunities among devices.
Energy Savings through Integration of the Illumination Natural and Artificial, Using a System of Automatic Dimming: Case Study
2013
The reduction of electrical energy consumption in buildings is a subject of great interest in the international scientific community. In buildings with a lot of available natural light, designed with large glazed surfaces, the artificial lighting system is often oversized and cannot be divided into segments to meet lighting demands during daylight hours.This article presents an experimental study, conducted in a university lecture hall that has a glazed surface covering the whole wall at one end, which provides a level of internal illumination that is only sufficient for the area next to the window itself, even when the outside lighting conditions are very bright. It is therefore necessary …
Multi-objective strategies for management and design of distributed electric storage systems in a Mediterranean island
2013
The paper proposes an analytical study about the design and operation of distributed Electrical Storage Systems(ESS) in an active distribution network supplying a Mediterranean island, according to different criteria. The approach is based on the application of a multi-objective optimization algorithm (NSGA-II) that outputs a set of optimized schedules of the ESS in different configurations when operated according to different criteria (minimum energy losses in the grid, total generation cost, greenhouse gas emissions, limiting the fluctuations of the generation from fossil fuel plants). Moreover the variability of the voltage profile has been investigated also by a comparison with a refere…