Search results for "Tort"

An harmonic test condition for the metrological characterization and the operating principle identification of reactive static meters

2008

This paper faces the problem of the metrological characterization of the static meters for reactive energy in the presence of harmonic distortion. Starting from the only available accuracy test condition in the presence of harmonics introduced in the Standards for active static meters, an experimental approach is proposed for the verification of such meters in the presence of harmonic distortion, as well as for the individuation of their operating principle. A theoretical validation of the obtained results is presented by means of a comparison with a standard and a commercial static meter with a known operating principle.

Static meters for the reactive energy in the presence of harmonics: an experimental metrological characterization

2009

Electricity metering plays a crucial role for all the commercial transactions on the energy market. Thus, an accurate evaluation of the performance of the electricity metering equipment is required not only in the reference operating conditions but also in the presence of disturbances affecting the power systems. As regards this matter, this paper analyzes the main aspects related to the metrological characterization of the static meters for the reactive energy in the presence of harmonic distortion. Attention is focused not only to the meters covered by the current standards but also to the meters of better accuracy and to the reference standard meters. The analysis is supported by several…

A New Measurement Method for the Detection of Harmonic Sources in Power Systems Based on the Approach of the IEEE Std. 1459–2000

2010

In this paper, a novel single-point strategy is proposed for the detection of the harmonic sources in power systems. The method is an improvement of a strategy previously proposed by the authors; it is developed from the IEEE Std 1459-2000 approach and it can be entirely implemented in the time domain, thus simplifying the measurement system. The effectiveness of the proposed method is evaluated by introducing simple decision-making rules and by taking the presence of the measurement transducers into account. Several simulations and experimental tests are presented, showing that the enhanced strategy is able to give an useful information on the detection of the dominant harmonic source upst…

A PC-based wattmeter for accurate measurements in sinusoidal and distorted conditions: Setup and experimental characterization

2012

This paper presents the development of a high-accuracy sampling wattmeter, which can be employed with both sinusoidal and distorted input signals. The proposed personal computer (PC)-based system is a simple, portable, and low-cost solution because it is based on two commercial data acquisition boards connected to a common PC. Owing to this solution, the voltage is sensed directly, avoiding expensive voltage dividers, while the current is sensed by means of a noninductive current shunt. Commercial software is also used for data processing and implementation of the virtual instrument. The setup of the PC-based wattmeter is described, with a detailed description of the correction strategy of …

Baseband predistorter using direct spline computation

2005

A baseband predistorter is presented. Key features of the predistorter reside in the use of cubic spline interpolation to generate predistorted input data to the power amplifier, without time convergence problems of classical approaches, with the goal of a reduction in the computational effort. Simulated behaviour of the proposed scheme is presented, demonstrating the effectiveness of the approach.

Phase Margin Degradation of a Peak Current Controlled Converter at Reduced Duty Cycle

2010

An inner current loop is frequently used in many switching power supplies to achieve higher stability and a good current sharing. Nevertheless, some problems derived from its practical implementation can be encountered. One problem is related to the need of filtering of the sensed current and was discovered by the authors in the implementation of a 500 W converter, when peak current control was applied by sensing the switch current. This paper will demonstrate mathematically that an RC filter not only filters out the noise but also can cause a degradation of the phase margin, especially, if the needed duty cycle is close to zero. The main reason for it is the severe distortion of the curren…

Medición del efecto látigo en redes de suministro

2016

La variabilidad de la demanda que se origina de un agente a otro en la cadena de suministro, aumenta o amplifica a medida que la señal se aleja del punto de origen; estas distorsiones se denominan Efecto Látigo. En este artículo se aborda una red de suministros multieslabón, que estima los intervalos de medición de la distorsión de la demanda de la red, de acuerdo a comportamientos extremos en el sistema que permiten diagnosticar su desempeño en términos de la amplificación de demanda. Para la investigación se aplican mediciones estáticas locales y globales del efecto látigo, en cada nivel de la red de suministros del juego de la cerveza de cuatro eta-pas; cada etapa o eslabón tiene múltipl…

Impact of integrating photovoltaic based DG on distribution network harmonics

2017

The process of integrating various distributed generation (DG) technologies in power system networks is increasing rapidly in the recent years. One major concern about the integration of DGs is their impact on network harmonics. The aim of this paper is to investigate the effects caused by the integration of photovoltaic DG in distribution networks on system harmonics. The penetration level, number of DG units, and their location are used as parameters in order to verify the effects of DG on system harmonics. Moreover, a study of single and double tuned filters is conducted as harmonics mitigation techniques. Detailed simulations using Matlab/Simulink are inserted in order to explain and ve…

Gozos a nuestra Señora del Buen Parto, venerada en el termino de Tortosa, en la Ermita, de la Virgen de la Providencia.

El full orlat. Grav. xil. enmarcat de "N.S. del Bon Part", flanquejat per ornaments florals. Text del goig a tres col separades per filets.

A Victim of a Road Traffic Accident Not Fastened by the Seat Belt and the EU Motor Insurance Law: CJEU Judgment in Vítor Hugo Marques Almeida

2013

This case note relates to the recent judgement (23 October 2012) by the Court of Justice of the European Union in the case No C-300/10 concerning interrelation of the European Union motor insurance law and the national civil liability regulation. As the civil liability arising from motor traffic accidents is not approximated by the European Union law, its regulation falls within the national law. Yet, application of the national civil liability law shall not undermine the obligation to provide insurance coverage for victims of road traffic accidents. The discussed case concerns a situation when a victim who was not fastened by a seat belt at the moment of a motor traffic accident was injure…