Search results for "Volt"
showing 10 items of 2187 documents
Experimental characterization of PEM fuel cells by micro-models for the prediction of on-site performance
2009
This paper presents the results of an experimental analysis performed on a miniaturized, 6 We Proton Exchange Membrane Fuel Cell (PEMFC) system, integrated with on-site hydrogen production by electrolysis; in particular, the effects of environmental parameters such as the external temperature and the humidity on the performance of fuel cells are investigated. PEMFC systems are zero-emissions power technologies when they are fed with pure hydrogen (at concentration higher than 97%); also, being the only results of system operation the produced electricity and some pure water, when produced by renewable sources hydrogen can be considered an attractive alternative to fossil fuels and may concu…
Study of the Audio Susceptibility in Parallel Power Processing With a High-Power Topology
2009
In this paper, the audio susceptibility characteristic of a high-efficiency nonisolated topology that processes only a part of the total power delivery is analyzed. Since the proposed topology presents a direct path from input to output, the effect of the input voltage ripple at the output voltage has been studied. The effect on the audio susceptibility of the values and disposition of the components and the effect of their parasitic elements must be taken into account. Due to this study, the analytical expression of the audio susceptibility and the design criteria to improve it have been obtained.
Least squares and genetic algorithms for parameter identification of induction motors
2001
Abstract This paper deals with off-line parameter identification of induction motors by means of least square (LS) techniques and genetic algorithms (GA), using stator voltages, stator currents and velocity as input–output data. For analytical identification by LS algorithms, filtering of experimental data is performed by means of anticausal filters. Two models useful for identification are derived in which the products of acceleration and rotor fluxes, usually neglected, are taken into account. The GA-based identification method consists of the determination of the best parameters which match input–output behaviour of the motor. Both methods are investigated and compared by means of experi…
A portable instrument for the location and identification of defects generating PD
2011
A portable instrument based on an antenna probe and suitable for partial discharge detection, have been characterized through both laboratory and on-site experiments carried out on coils and stator windings of ac rotating machines. The antenna probe allows the capture of electromagnetic waves in a bandwidth of 0.1–100 MHz. Pulse signals and ac supply voltage reference are obtained by means of high-pass and low-pass filters, respectively, so avoiding the need of a direct connection with the objects under test. By this way, real-time phase resolved partial discharge patterns can be derived. Results of a comparison of the diagnostic information provided by PD patterns due to conducted and irra…
Technical and economical evaluation on the use of reconfiguration systems in some EU countries for PV plants
2017
This paper shows the technical and economical evaluation of the application of a reconfiguration system for photovoltaic (PV) plants, considering the incentives system in some European Union countries. The reconfiguration system is an alternative to the distributed maximum power point tracking technique which used to increase the power production in the PV plants under the mismatch phenomenon. The reconfiguration techniques employ a microprocessor-based or field-programmable gate array-based system that modifies the layout of the PV plant through the change of the connections among modules. After having presented the main features working of the PV reconfiguration system allowing the improv…
On-grid residential development with photovoltaic systems in Southern Norway
2013
The application of residential photovoltaic (PV) systems is increasing rapidly worldwide. In Southern Norway, a group of on-grid smart houses with embedded PV systems, solar thermal collectors, and geothermal heat pumps are under development at Skarpnes. In this paper, performance analysis based on simulations of an on-grid residential house with PV system located at Skarpnes is presented. This project is expected to demonstrate zero energy and zero emission housing in Norway. This paper discusses a theoretical study of home energy consumption with electricity production for a single house from a PV system, including simulations of irradiation conditions and tilt angles, and of the PV syste…
On the use of narrow band power line as communication technology for medium and low voltage smart grids
2012
The aim of this work is to perform a feasibility study on the power line communication for the development of a new generation of interface devices (IDs) for smart grid applications. More in detail, this paper deals with one of the most important issues on this topic which is the communication system. Among the existing communication technologies, the study is focused on power line communications (PLCs). After a analysis of the state of the art in the field, the main aspects are analyzed, concerning the open issues on the use of PLCs, especially for medium voltage (MV) and low voltage (LV) systems. In this work the use of PLC in MV-LV networks is investigated, by means of simulations and ex…
New Power Conditioning System for Battery-free Satellite Buses with Maximum Power Point Tracking
2007
The purpose of this paper is describe a new conception of Power Conditioning Unit (PCU) developed to fulfill the requirements of BepiColombo Electronic Propulsion module. This load bus has very tough specification especially regarding transient response during total load switch-off ("beam out") which has to be less than 2% of the bus voltage. The conception we propose, is the new Sequential Switching Shunt Maximum Power Regulator (S3MPR) consisting in a S3R, to keep the SA voltage at its Maximum Power Point (MPP) followed by a Boost regulator to produce a constant 100V to supply the Electronic Propulsion (EP). This concept may also be of interest for other future missions involving high pow…
Mitigation of 50 Hz magnetic field produced by an overhead transmission line
2015
Power transmission utilities are challenged by the need to expand transmission system capacity to meet growing energy demands. The impact of high voltage overhead transmission lines on the environment represents a hot topic in the context of transport and distribution of electrical energy. In particular, interest towards the effects of extra low frequency (ELF) magnetic fields generated by high-voltage power transmission lines has been increasing significantly during the last decade, giving rise to a number of policy initiatives and research activities. Therefore, the evaluation of the magnetic field generated by conductors of overhead lines is of primary importance in order to develop meth…
Comparative evaluation of pulse width modulation techniques on effective DC link voltage utilization of grid connected inverter
2016
In this paper, comparison between two different Pulse Width Modulation (PWM) techniques employed for three phase voltage source inverter (VSI) is discussed. The three phase voltage source inverter is basic topology used to supply a grid. In this paper we have design a LC filter between the inverter and the grid in order to stabilize the output voltage. The filter gives sinusoidal three phase voltage at the output of the inverter with almost zero/less harmonic distortion. A suitable PWM technique is employed to obtain the required output voltage in the line side of the inverter. The PWM generation techniques used mainly based on sinusoidal based Pulse Width Modulation (SPWM) and Space Vector…