Search results for "Wire"

Nano-structured PbO2 electrode for lead-acid battery

2014

Test procedures for use of wireless partial discharges instrumentation in HV networks

2014

On-field diagnostic methods based on Partial Discharge (PD) measurements for asset assessment in High Voltage (HV) sectors are experiencing a constant growth in recent years. This rise of interest motivated the research toward faster, reliable and less expensive methods and technologies to perform PD measurements. Recently, a portable instrument based on a wideband antenna sensor, intended for accurate partial discharge measurements, has been developed by the authors. This sensor allows to capture electromagnetic waves in a bandwidth ranging from 0.1-100 MHz as well as the electric field of the AC supply voltage to be used as a phase reference. This approach completely avoid the need of a d…

Design and experimental characterization of a low-cost, real-time, wireless AC monitoring system based on ATmega 328P-PU microcontroller

2015

This paper describes the development and experimental characterization of a real-time, low-cost, wireless AC monitoring system based on ATmega 328P-PU microcontroller. The proposed system is composed by a main brain for the acquisition and the processing of the data measured by smart meters. From the experimental tests discussed in this work it is demonstrated that the proposed system can monitor, with adequate accuracy, the working cycles of electrical loads in order to evaluate its energy consumption.

A Novel Framework of Hybrid Harvesting Mechanisms for Remote Sensing Devices

2022

Sensing networks have recently proven to be useful in a variety of disciplines. The use of mobile sensing robots and unmanned aerial vehicles (UAVs) is intended to lessen the burden of sensor node energy consumption. However, conserving energy in the networks remains a major concern. In this work, a design of a hybrid RF-Solar harvesting system to support sensing devices is investigated. The harvesting circuits may collect energy from both solar and radio frequency (RF) resources that are commonly available in ambient environments. This approach creates hybrid harvesting circuits for all elements in the combined sensor networks by combining RF and solar harvester circuits. The RF harvester …

Hybrid Solar-RF Energy Harvesting Mechanisms for Remote Sensing Devices

2022

Recently, sensor networks effectively provide many applications in different fields. The deployment of mobile sensors, unmanned aerial vehicles is to reduce the burden of energy consumption for sensor nodes. However, saving energy in such networks is still a critical issue. This paper investigates the performance of a hybrid RF-Solar harvesting circuit for remote sensing devices. The harvesting circuit can simultaneously harvest power from solar and radio frequency (RF) sources readily available in the surrounding environment. The proposed work builds RF and solar harvester circuits to create hybrid harvesting circuits for all elements in the combined sensing networks. The stand-alone RF ha…

WIRELESS DETECTION OF PD PATTERNS: APPLICATIONS IN SMART GRIDS AND MODERN POWER SYSTEMS

In this thesis, different challenges for various applications of a wireless PD detection instrument are discussed and relevant solutions are proposed. The main purpose is to assess the applicability of such technology both in current HV and MV power systems as well as in future applications for smart grids. The main challenges for these types of diagnostic systems are the following: • voltage synchronization of Phase Resolved PD pattern; • PD recognition under non-sinusoidal voltage waveforms; • PD recognition under sinusoidal voltage superimposed harmonics; • PD recognition in laboratory and in real world situations under noise and other source of disturbance. Thanks to the collaboration w…

Revealing Transmit Diversity Mechanisms in Commercial IEEE 802.11 Cards

2008

Service differentiation in WLAN has been traditionally faced at the MAC layer. However, some PHY layer parameters, such as the transmission power, the antenna, and the modulation/coding scheme, have a deep impact on network performance. Since the criterion for selecting these parameters is left to the vendor specific implementations, the performance spread of most experimental results about 802.11 WLAN could be affected by vendor proprietary schemes. The focus of this paper is an experimental analysis of the undisclosed antenna diversity mechanisms employed by some widely used cards (namely, the Atheros and Intel based cards), and a thorough understanding of the optimization goals which gui…

An Embedded System for the integration of a Combined Photovoltaic Solar (CPS) system into a ZigBee Home Area Network

2011

In this paper is reported the design and implementation of an electronic system capable of communicating over a standard ZigBee network in order to let a residential gateway collector, named agent, gain access to the parameters of a Combined Photovoltaic and Solar thermal (CPS) plant, thus realizing a networked energy production appliance . The system is made of three parts: a PV metering device, a boiler metering device also capable of controlling a heating resistor embedded within the boiler tank, and a data collector acting as a ZigBee node. The data collector device periodically retrieves the following parameters from the metering devices: instantaneous photovoltaic power production, ac…

The FP7 BeyWatch European scientific project: general features and design criteria of the Combined Photovoltaic Solar (CPS) system within the BEYWATC…

2011

This paper includes the general features and design criteria of a combined photovoltaic solar system (CPS) and its allocation within the entire architecture of the BeyWatch system. The CPS main functionalities and characteristics, the description of the CPS main components and the CPS electronic control and monitoring subsystem, together with the description of the Firmware design and communication protocols are here reported. The Combined Photovoltaic and Solar system (CPS) is a Renewable Energy system that produces thermal and electrical energy and the design has been based on a modular approach.

Realizing airtime allocations in multi-hop Wi-Fi networks: A stability and convergence study with testbed evaluation

2019

Abstract REACT is a distributed resource allocation protocol used to negotiate a max–min allocation of airtime for multi-hop ad hoc wireless networks. Two approaches are proposed for a node to realize its REACT allocation in a contention-based MAC protocol. This is achieved by tuning its contention window to a value that corresponds to its allocation. Only a change in the allocation, due to a change in local traffic requirements or local network views, results in re-tuning. The approaches for tuning are implemented in commercial Wi-Fi devices and their stability and convergence are studied experimentally in the w-iLab.t wireless network testbed. These properties are also studied analyticall…