Refined Modeling and Compensation of Current Transformers Behavior for Line Parameters Estimation Based on Synchronized Measurements

Nowadays, in modern management and control applications, line parameters need to be known more accurately than in the past to achieve a reliable operation of the distribution grids. Phasor measurement units (PMUs) may improve line parameter estimation processes, but the accuracy of the result is affected by all the elements of the PMU-based measurement chain, in particular by the instrument transformers. Current transformers (CTs) are nonlinear and, therefore, their behavior is not easily described: their models cannot be straightforwardly included in the estimation problem. In this regard, this article refines modeling and compensation of CT systematic errors in line parameter estimation processes, based on different methods to describe the transformer behavior under various operating conditions. As the main result, the systematic errors of CTs are remarkably identified and mitigated. Moreover, the estimation of shunt susceptance values is significantly improved

Tecniche di ottimizzazione per la stima e il monitoraggio di sistemi elettrici di potenza

The evolution of modern electric power grids requires increasingly complex, flexible, and effective management and control tools. These rely on data obtained from monitoring systems consisting of measurement instruments with advanced features but still characterized by uncertainty, and of estimation methods influenced by all the uncertainty sources of the measurement chain. Consequently, the availability of mathematical tools able to effectively model estimation problems, fully exploiting the characteristics of measurement instruments and a priori knowledge, is increasingly important. The thesis explores an approach based on optimization techniques to some relevant problems of estimation and monitoring designed for the power systems. The aim is to optimize the estimation performance through the integration in the problem formulation of a priori information on the domain under investigation and on the state to be reconstructed, exploiting the available knowledge on measurement errors. The considered optimization formulations involve two terms: the approximation error and the regularization term. The first one, also called fitting term, evaluates how well the solution matches the available measurements, while the regularization term considers the a priori information on the solution to be recovered. The estimation problems addressed in the thesis are the estimation of the main sources of harmonic pollution, i.e., the Harmonic Source Estimation (HSoE), in a distribution network and the simultaneous estimation of transmission line parameters and systematic errors in the measurement chain. In both cases, synchronized phasor measurements (at fundamental or harmonic frequency), available from a new generation of measurement devices, are considered. The identification of the prevailing harmonic sources is modelled as an underdetermined problem with a sparse solution and is addressed by using the Compressive Sensing approach as an L1 minimization. The problem is faced using first the L1 minimization with equality constraints, then, starting from the theoretical aspects involved in the evaluation of measurement uncertainties, and aiming at the reduction of their impact on HSoE algorithms, a new formulation based on the L1 minimization with quadratic constraints is proposed. To maximize the algorithm performance, a whitening matrix that allows retrieving the information on the distributions of the measurement errors, and thus estimating the corresponding energy bounds, is presented. The effectiveness of the presented solution is evaluated by simulations on appropriate test networks. The simultaneous estimation of line parameters and systematic errors of the measurement chain is addressed by a new method based on synchronized measurements by phasor measurement units (PMUs). The method is conceived to exploit a multiple-branch approach and a potentially large number of obtained measurements, corresponding to multiple operating conditions. The method is designed in the context of Tikhonov regularization and allows exploiting the high accuracy and reporting rate of PMUs more effectively, to improve the estimation of line parameters and to refine the compensation of systematic measurement errors, particularly from instrument transformers. The validity of the proposal has been verified through simulations performed on the IEEE 14-bus test system. The validity of the proposed paradigm has been confirmed by all the applications and experiments conducted. The flexibility of the optimization techniques discussed in this thesis has in fact made it possible to model the various a priori information about the considered domain and the state to be recovered, exploiting any type of available knowledge on measurement errors. These techniques can therefore be considered a valid, flexible, and effective tool for addressing the new measurement problems posed by modern electric power grids

Same-day transfer for the invasive strategy of patients with non-ST-segment elevation acute coronary syndrome admitted to spoke hospitals: Data from the Emilia-Romagna Regional Network

Background: The service strategy (same-day transfer between spoke hospital and hub centre with catheterisation laboratory (cath-lab) facility to perform invasive procedures) has been suggested to improve the management of patients with non-ST-segment elevation acute coronary syndrome (NSTEACS) admitted to spoke hospitals. We used data from a large prospective Italian registry to describe application, performance and outcome of the service strategy in the daily clinical practice. Methods: This study was based on an observational, post-hoc analysis of all consecutive NSTEACS patients admitted to spoke non-invasive hospitals of the Emilia-Romagna regional network and receiving coronary artery angiography (CAA)percutaneous coronary intervention (PCI). We evaluated: application of service strategy, time to cath-lab access, hospital stay length, 30-days occurrence of adverse events. Results: From January 2011-December 2012, 2952 NSTEACS consecutive patients were admitted to spoke non-invasive hospitals and received CAA. Overall, 1765 (60%) patients were managed with a service strategy. After multivariable analysis, service strategy emerged as independent predictor of faster access to cath-lab (within 72 h: hazard ratio (HR) 2.3, 95% confidence interval (CI) 1.9-2.7, p<0.0001; within 24 h: HR 2.8, 95% CI 2.2-3.3, p<0.0001, respectively). Service strategy significantly reduced hospital stay length (-5.5 days, p<0.0001). We estimated a mean of Euro1590 saved for each patient managed with service strategy. Thirty-day occurrence of adverse events did not differ between patients managed with or without a service strategy. Conclusions: In our daily clinical practice, a service strategy seems to be an effective approach to optimise the invasive management of NSTEACS patients admitted to spoke hospitals

Safety and efficacy of ombitasvir/paritaprevir/ritonavir/dasabuvir plus ribavirin in patients over 65 years with HCV genotype 1 cirrhosis

none191norestrictedAscione, Antonio*; De Luca, Massimo; Melazzini, Mario; Montilla, Simona; Trotta, Maria Paola; Petta, Salvatore; Puoti, Massimo; Sangiovanni, Vincenzo; Messina, Vincenzo; Bruno, Savino; Izzi, Antonio; Villa, Erica; Aghemo, Alessio; Zignego, Anna Linda; Orlandini, Alessandra; Fontanella, Luca; Gasbarrini, Antonio; Marzioni, Marco; Giannini, Edoardo G.; Craxì, Antonio; Abbati, Giuseppe; Alberti, Alfredo; Andreone, Pietro; Andreoni, Massimo; Angeli, Paolo; Angelico, Mario; Angarano, Gioacchino; Angrisani, Debora; Antinori, Andrea; Antonini, Cinzia; Avancini, Ivo; Barone, Michele; Bruno, Raffaele; Benedetti, Antonio; Bernabucci, Veronica; Blanc, Pier; Boarini, Chiara; Boffa, Nicola; Boglione, Lucio; Borghi, Vanni; Borgia, Guglielmo; Brancaccio, Giuseppina; Brunetto, Maurizia; Cacciola, Irene; Calabrese, Paolo; Calvaruso, Vincenza; Campagnolo, Davide; Canovari, Benedetta; Caporaso, Nicola; Capra, Franco; Carolo, Giada; Cassola, Giovanni; Castelli, Francesco; Cauda, Roberto; Silberstein, Francesca Ceccherini; Cecere, Roberto; Chessa, Luchino; Chiodera, Alessandro; Chirianni, Antonio; Ciancio, Alessia; Cima, Serena; Coco, Barbara; Colombo, Massimo; Coppola, Nicola; Corti, Giampaolo; Cosco, Lucio; Corradori, Silvia; Cozzolongo, Raffaele; Cristaudo, Antonio; Danieli, Elena; Monforte, Antonella D’Arminio; Monache, Marco delle; Del Poggio, Paolo; de Luca, Andrea; Dentone, Chiara; Di Biagio, Antonio; Di Leo, Alfredo; Di Perri, Giovanni; Di Stefano, Marco; D’Offizi, Giampiero; Donato, Francesca; Durante, Emanuele; Erne, Elke; Fagiuoli, Stefano; Falasca, Katia; Federico, Alessandro; Felder, Martina; Ferrari, Carlo; Gaeta, Giovanni Battista; Ganga, Roberto; Gatti, Pietro; Giacomet, Vania; Giacometti, Andrea; Gianstefani, Alice; Giordani, Maria; Giorgini, Alessia; Grieco, Antonio; Guerra, Michele; Gulminetti, Roberto; Ieluzzi, Donatella; Imparato, Michele; Iodice, Valentina; La Monica, Silvia; Lazzarin, Adriano; Lenzi, Marco; Levrero, Massimo; Lichtner, Myriam; Lionetti, Raffaella; Guercio, Carmela Lo; Madonna, Salvatore; Magnani, Silvia; Maida, Ivana; Marignani, Massimo; Marrone, Aldo; Marsetti, Fabio; Martini, Silvia; Masarone, Mario; Maserati, Renato; Mastroianni, Claudio Maria; Memoli, Massimo; Menzaghi, Barbara; Merli, Manuela; Miele, Luca; Milella, Michele; Mondelli, Mario; Montalbano, Marzia; Monti, Monica; Morelli, Olivia; Morisco, Filomena; Nardone, Gaetano; Novara, Sergio; Onnelli, Giovanna; Onofrio, Mirella; Paganin, Simona; Pani, Luca; Parisi, Maria Rita; Parruti, Giustino; Pasquazzi, Caterina; Pasulo, Luisa; Perno, Carlo Federico; Persico, Marcello; Piai, Guido; Picciotto, Antonino; Pigozzi, Grazielle Marie; Piovesan, Sara; Piras, Maria Chiara; Pirisi, Massimo; Piscaglia, Anna Maria; Ponti, Laura; Potenza, Domenico; Pravadelli, Cecilia; Quartini, Mariano; Quirino, Tiziana; Raimondo, Giovanni; Rapaccini, Gian Ludovico; Rendina, Maria; Rizzardini, Giuliano; Rizzetto, Mario; Rizzo, Salvatore; Romagnoli, Dante; Romano, Antonietta; Rossi, Cristina; Rumi, Maria Grazia; Russello, Maurizio; Russo, Francesca Paolo; Russo, Maria Luisa; Sansonno, Domenico Ettore; Santantonio, Teresa Antonia; Saracco, Giorgio; Schimizzi, Anna Maria; Serviddio, Gaetano; Simeone, Filomena; Solinas, Attilio; Soria, Alessandro; Tabone, Marco; Taliani, Gloria; Tarantino, Giuseppe; Tarquini, Pierluigi; Tavio, Marcello; Termite, Antonio; Teti, Elisabetta; Toniutto, Pierluigi; Torti, Carlo; Tundi, Paolo; Vecchiet, Giacomo; Verucchi, Gabriella; Gentilucci, Umberto Vespasiani; Vinci, Maria; Vullo, Vincenzo; Zolfino, Teresa; Zuin, MassimoAscione, Antonio; De Luca, Massimo; Melazzini, Mario; Montilla, Simona; Trotta, Maria Paola; Petta, Salvatore; Puoti, Massimo; Sangiovanni, Vincenzo; Messina, Vincenzo; Bruno, Savino; Izzi, Antonio; Villa, Erica; Aghemo, Alessio; Zignego, Anna Linda; Orlandini, Alessandra; Fontanella, Luca; Gasbarrini, Antonio; Marzioni, Marco; Giannini, Edoardo G.; Craxì, Antonio; Abbati, Giuseppe; Alberti, Alfredo; Andreone, Pietro; Andreoni, Massimo; Angeli, Paolo; Angelico, Mario; Angarano, Gioacchino; Angrisani, Debora; Antinori, Andrea; Antonini, Cinzia; Avancini, Ivo; Barone, Michele; Bruno, Raffaele; Benedetti, Antonio; Bernabucci, Veronica; Blanc, Pier; Boarini, Chiara; Boffa, Nicola; Boglione, Lucio; Borghi, Vanni; Borgia, Guglielmo; Brancaccio, Giuseppina; Brunetto, Maurizia; Cacciola, Irene; Calabrese, Paolo; Calvaruso, Vincenza; Campagnolo, Davide; Canovari, Benedetta; Caporaso, Nicola; Capra, Franco; Carolo, Giada; Cassola, Giovanni; Castelli, Francesco; Cauda, Roberto; Silberstein, Francesca Ceccherini; Cecere, Roberto; Chessa, Luchino; Chiodera, Alessandro; Chirianni, Antonio; Ciancio, Alessia; Cima, Serena; Coco, Barbara; Colombo, Massimo; Coppola, Nicola; Corti, Giampaolo; Cosco, Lucio; Corradori, Silvia; Cozzolongo, Raffaele; Cristaudo, Antonio; Danieli, Elena; Monforte, Antonella D’Arminio; Monache, Marco delle; Del Poggio, Paolo; de Luca, Andrea; Dentone, Chiara; Di Biagio, Antonio; Di Leo, Alfredo; Di Perri, Giovanni; DI STEFANO, Marco; D’Offizi, Giampiero; Donato, Francesca; Durante, Emanuele; Erne, Elke; Fagiuoli, Stefano; Falasca, Katia; Federico, Alessandro; Felder, Martina; Ferrari, Carlo; Gaeta, Giovanni Battista; Ganga, Roberto; Gatti, Pietro; Giacomet, Vania; Giacometti, Andrea; Gianstefani, Alice; Giordani, Maria; Giorgini, Alessia; Grieco, Antonio; Guerra, Michele; Gulminetti, Roberto; Ieluzzi, Donatella; Imparato, Michele; Iodice, Valentina; La Monica, Silvia; Lazzarin, Adriano; Lenzi, Marco; Levrero, Massimo; Lichtner, Myriam; Lionetti, Raffaella; Guercio, Carmela Lo; Madonna, Salvatore; Magnani, Silvia; Maida, Ivana; Marignani, Massimo; Marrone, Aldo; Marsetti, Fabio; Martini, Silvia; Masarone, Mario; Maserati, Renato; Mastroianni, Claudio Maria; Memoli, Massimo; Menzaghi, Barbara; Merli, Manuela; Miele, Luca; Milella, Michele; Mondelli, Mario; Montalbano, Marzia; Monti, Monica; Morelli, Olivia; Morisco, Filomena; Nardone, Gaetano; Novara, Sergio; Onnelli, Giovanna; Onofrio, Mirella; Paganin, Simona; Pani, Luca; Parisi, Maria Rita; Parruti, Giustino; Pasquazzi, Caterina; Pasulo, Luisa; Perno, Carlo Federico; Persico, Marcello; Piai, Guido; Picciotto, Antonino; Pigozzi, Grazielle Marie; Piovesan, Sara; Piras, Maria Chiara; Pirisi, Massimo; Piscaglia, Anna Maria; Ponti, Laura; Potenza, Domenico; Pravadelli, Cecilia; Quartini, Mariano; Quirino, Tiziana; Raimondo, Giovanni; Rapaccini, Gian Ludovico; Rendina, Maria; Rizzardini, Giuliano; Rizzetto, Mario; Rizzo, Salvatore; Romagnoli, Dante; Romano, Antonietta; Rossi, Cristina; Rumi, Maria Grazia; Russello, Maurizio; Russo, Francesca Paolo; Russo, Maria Luisa; Sansonno, Domenico Ettore; Santantonio, Teresa Antonia; Saracco, Giorgio; Schimizzi, Anna Maria; Serviddio, Gaetano; Simeone, Filomena; Solinas, Attilio; Soria, Alessandro; Tabone, Marco; Taliani, Gloria; Tarantino, Giuseppe; Tarquini, Pierluigi; Tavio, Marcello; Termite, Antonio; Teti, Elisabetta; Toniutto, Pierluigi; Torti, Carlo; Tundi, Paolo; Vecchiet, Giacomo; Verucchi, Gabriella; Gentilucci, Umberto Vespasiani; Vinci, Maria; Vullo, Vincenzo; Zolfino, Teresa; Zuin, Massim

Lung recruitment before surfactant administration in extremely preterm neonates with respiratory distress syndrome (IN-REC-SUR-E): a randomised, unblinded, controlled trial

Background: The importance of lung recruitment before surfactant administration has been shown in animal studies. Well designed trials in preterm infants are absent. We aimed to examine whether the application of a recruitment manoeuvre just before surfactant administration, followed by rapid extubation (intubate-recruit-surfactant-extubate [IN-REC-SUR-E]), decreased the need for mechanical ventilation during the first 72 h of life compared with no recruitment manoeuvre (ie, intubate-surfactant-extubate [IN-SUR-E]). Methods: We did a randomised, unblinded, controlled trial in 35 tertiary neonatal intensive care units in Italy. Spontaneously breathing extremely preterm neonates (24 + 0 to 27 + 6 weeks' gestation) reaching failure criteria for continuous positive airway pressure within the first 24 h of life were randomly assigned (1:1) with a minimisation algorithm to IN-REC-SUR-E or IN-SUR-E using an interactive web-based electronic system, stratified by clinical site and gestational age. The primary outcome was the need for mechanical ventilation in the first 72 h of life. Analyses were done in intention-to-treat and per-protocol populations, with a log-binomial regression model correcting for stratification factors to estimate adjusted relative risk (RR). This study is registered with ClinicalTrials.gov, NCT02482766. Findings: Of 556 infants assessed for eligibility, 218 infants were recruited from Nov 12, 2015, to Sept 23, 2018, and included in the intention-to-treat analysis. The requirement for mechanical ventilation during the first 72 h of life was reduced in the IN-REC-SUR-E group (43 [40%] of 107) compared with the IN-SUR-E group (60 [54%] of 111; adjusted RR 0·75, 95% CI 0·57–0·98; p=0·037), with a number needed to treat of 7·2 (95% CI 3·7–135·0). The addition of the recruitment manoeuvre did not adversely affect the safety outcomes of in-hospital mortality (19 [19%] of 101 in the IN-REC-SUR-E group vs 37 [33%] of 111 in the IN-SUR-E group), pneumothorax (four [4%] of 101 vs seven [6%] of 111), or grade 3 or worse intraventricular haemorrhage (12 [12%] of 101 vs 17 [15%] of 111). Interpretation: A lung recruitment manoeuvre just before surfactant administration improved the efficacy of surfactant treatment in extremely preterm neonates compared with the standard IN-SUR-E technique, without increasing the risk of adverse neonatal outcomes. The reduced need for mechanical ventilation during the first 72 h of life might facilitate implementation of a non-invasive respiratory support strategy. Funding: None