Search results for "TTR"
showing 10 items of 3945 documents
Transient stability simulation of a fixed speed wind turbine by Matlab/Simulink
2007
This paper describes the dynamic behavior of a typical fixed speed wind turbine connected to the grid; the model is developed in the simulation tool Matlab/Simulink and created as a modular structure. The pitch control system is used for stabilization of the wind turbine at grid faults. In this way, voltage stability of the system with grid-connected wind turbines can be improved by using blade-angle control for a temporary reduction of the wind turbine power during a short-circuit fault in the grid. This paper shows a new variable control for maintaining of voltage stability, when a three-phase fault is applied close to the wind turbine and cleared by disconnecting the affected line. In th…
Information Dynamics of Electric Field Intensity before and during the COVID-19 Pandemic.
2022
This work investigates the temporal statistical structure of time series of electric field (EF) intensity recorded with the aim of exploring the dynamical patterns associated with periods with different human activity in urban areas. The analyzed time series were obtained from a sensor of the EMF RATEL monitoring system installed in the campus area of the University of Novi Sad, Serbia. The sensor performs wideband cumulative EF intensity monitoring of all active commercial EF sources, thus including those linked to human utilization of wireless communication systems. Monitoring was performed continuously during the years 2019 and 2020, allowing us to investigate the effects on the patterns…
Contributo allo studio sul valore probatorio delle e-mail
2019
L'autore affronta il problema, assai dibattuto, della natura e del conseguente valore probatorio dell'e-mail. Dopo aver passato in rassegna le possibili soluzioni conclude per la natura di documento informatico sottoscritto con firma semplice. Invero la firma elettronica (analogamente a quanto accade per altre fattispecie, come gli acquisti di beni e servizi presso piattaforme online) è apposta nell'e-mail attraverso un procedimento a formazione progressiva, nel corso del quale il firmatario è chiamato ad autenticarsi tramite le proprie credenziali (username e password), a navigare e digitare il messaggio in modalità “autenticata” e a confermare la propria volontà di inviare il messaggio at…
Earth resistance measurements in urban contexts: Problems and possible solutions
2017
Both EN 50522 and IEEE Std. 81 propose the Fall of Potential Method (FPM) to carry out the measurement of the resistance to earth of an Earthing System (ES). However, in urban areas, the recommended distances between the ES and auxiliary electrodes are not easy to respect, due to the presence of buildings and tarmac. Moreover, unknown buried metallic parts, as well as the interconnection among the ESs made by the Distributor System Operator, could modify the earth potential profile of the area, affecting the measurement results. In this paper, the issues that could affect the measurement result if FPM is used in an urban context are presented. A parametric analysis, carried out with Comsol …
Considering safety issues in minimum losses reconfiguration for MV distribution networks
2009
This paper offers a new perspective over the traditional problem of the multiobjective optimal reconfiguration of electrical distribution systems in regular working state. The issue is indeed here formulated including also safety issues. Indeed, dimensioning the earth electrodes of their own secondary substations, distribution companies take into account the probable future configurations of the network due to transformations of overhead lines into cable lines or realization of new lines. On the contrary, they do not consider that, during normal working conditions. the structure of the network can be modified for long periods as a consequence of reconfiguration manoeuvres, with differences …
Psychological adjustment and victim-blaming among intimate partner violence offenders: The role of social support and stressful life events
2013
AbstractIntimate partner violence offenders often use victim-blaming attributions to explain their own violent behavior. These attributions represent an important challenge for intervention programs for intimatepartner violence offenders. The main objectives of this study were to analyze both the influence of social support and stressful life events on the psychological adjustment (self-esteem and depressive symptomatology) of intimate partner violence offenders and the relationship between offenders’ psychological adjustment and their victim-blaming attributions. The sample consists of 314 men convicted of intimate partner violence who were referred to a community-based intervention progra…
Multi-modal search for multiobjective optimization: an application to optimal smart grids management
2012
This paper studies the possibility to use efficient multimodal optimizers for multi-objective optimization. In this paper, the application area considered for such new approach is the optimal dispatch of energy sources in smart microgrids. The problem indeed shows a non uniform Pareto front and requires efficient optimal search methods. The idea is to exploit the potential of agents in population-based heuristics to improve diversity in the Pareto front, where solutions show the same rank and are thus equally weighted. Since Pareto dominance is at the basis of the theory of multi-objective optimization, most algorithms show the non dominance ranking as quality indicator, with some problem i…
LA SENTINELLA GLOBALE. I campi elettromagnetici del MUOS di Niscemi e i loro effetti.
2017
Il MUOS (Mobile User Objective System), un radar installato in Sicilia proprio all’interno della riserva “sughereta di Niscemi”, è una delle quattro sentinelle del sistema globale che la Us Navy ha realizzato nei vari angoli del mondo per tenere sott’occhio tutto il pianeta. La storia di questo impianto è fatta di promesse non mantenute, di interventi politici pro MUOS poi sconfessati dalla magistratura, di proteste organizzate nel tentativo di interloquire con quei poteri, che pure erano sembrati disponibili. Al fondo delle azioni del movimento NO MUOS, che qui vengono ricordate insieme all’analogo caso di Radio Vaticana che all’inizio degli anni Duemila scosse il mondo politico italiano, …
EFFETTI DEL CAMPO MAGNETICO ELF SU ALCUNE SPECIE VEGETALI DI INTERESSE ORNAMENTALE ED ECOLOGICO
2015
Diversi studi riportati nella letteratura scientifica di riferimento, effettuati sia in vivo che in vitro, hanno evidenziato effetti positivi determinati dall’esposizione dei tessuti vegetali al campo magnetico ELF
Impact of Nonlinear Inductor on Efficiency and Power Losses in a SMPS: a Case Study
2022
This paper proposes a comparative analysis focused on losses in two Switched Mode Power Supplies, adopting a linear inductor and an inductor operated up to saturation, respectively. The use of the nonlinear inductor saves weight and cost on the magnetic material, which is of great interest for automotive applications; however, it increases the peak current and can increase losses. The analysis aims to compare, by simulations, the impact on the efficiency of the different current waveforms throughout the converter. The losses are discussed in detail and calculated for each component of the converters.