Chapter Habitat and flora monitoring in the Regional Nature Reserve of "Palude del Conte e Duna Costiera di Porto Cesareo" (Puglia, Italy)

This study describes the results of the monitoring activity on habitats and plant species in the Regional Nature Reserve of "Palude del Conte e Duna Costiera di Porto Cesareo" (Puglia, Italy) and in the adjoining special areas of conservation (SACs), in the period April-December 2018. The activity combined field vegetation surveys and interpretation of orthophotos on a GIS system. The study identifies the pressure and threat factors that negatively affect the conservation of habitats

Improving DTR assessment by means of PCA applied to wind data

open5Traditionally, the rating of an overhead transmission line is determined under a set of specified and standardized conditions. However, weather conditions along the line change during operation. Therefore, the standard rating of the line might be either underestimated, leading to inefficient utilization of the line, or overestimated, leading to unsecure operation. This is the major drawback of the traditional approach: the so-called dynamic thermal rating (DTR), that takes into account the actual operating conditions along the line to determine the rating, is today a critical need. In this paper, we develop a comprehensive methodology for exploring all necessary information about stochastic processes of environmental variables surrounding and along the line using available data. The results can be used as input to determine the actual rating of the considered transmission line to enhance the determination of the rating for transmission lines.openBosisio, Alessandro*; Berizzi, Alberto; Le, Dinh-Duong; Bassi, Fabio; Giannuzzi, GiorgioBosisio, Alessandro; Berizzi, Alberto; Le, DINH DUONG; Bassi, Fabio; Giannuzzi, Giorgi

On-Line Estimation Assessment of Power Systems Inertia With High Penetration of Renewable Generation

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An Original Educational Algorithm Assessing the Behaviours of Angular Frequency Deviations of a Multimachine System in Small Signal Analysis

The paper presents a fully self-implementable algorithm that has demonstrated to be an effective tool for power education at the University of Padova-Department of Industrial Engineering. It deals with the small signal analysis of the electromechanical transients of a multimachine system. The algorithm allows analytically building both the state matrix and the input matrix. Moreover, by exploiting the matrix exponential, the angular frequency deviations of synchronous generators can be computed and plotted so to help students to evaluate transient stability. Besides the full exposition of the algorithm, the paper presents a comparison between a self-implemented linearized dynamic in Matlab environment and the dynamic simulation obtained by the commercial software DIgSILENT PowerFactory

A Novel Modeling for Assessing Frequency Behavior During a Hydro-to-Thermal Plant Black Start Restoration Test

Northern electric grid of Italy was involved in a black start mock drill. This test took place on November 2016 in order to check the coordination and efficiency of all the operational staffs and the automatic regulators involved in the case of a real blackout scenario. This paper presents the results of a research carried out in collaboration with Terna Rete Italia (the Italian Transmission System Operator), in order to find strengths and weaknesses and eventually to upgrade the existing restoration plan. Starting from the measures coming from generating plants and substations bars, the model of frequency regulation system for both the participating hydro and thermal power plants is developed. This work gives the system operator an essential tool to understand many complex dynamics and phenomena occurred during the test. At the same time, a robust model simulating the system behavior with different grid configurations is presented: it gives the opportunity to enhance both the classical power system control theory and the black start practices

Effects of Anacetrapib in Patients with Atherosclerotic Vascular Disease

BACKGROUND: Patients with atherosclerotic vascular disease remain at high risk for cardiovascular events despite effective statin-based treatment of low-density lipoprotein (LDL) cholesterol levels. The inhibition of cholesteryl ester transfer protein (CETP) by anacetrapib reduces LDL cholesterol levels and increases high-density lipoprotein (HDL) cholesterol levels. However, trials of other CETP inhibitors have shown neutral or adverse effects on cardiovascular outcomes. METHODS: We conducted a randomized, double-blind, placebo-controlled trial involving 30,449 adults with atherosclerotic vascular disease who were receiving intensive atorvastatin therapy and who had a mean LDL cholesterol level of 61 mg per deciliter (1.58 mmol per liter), a mean non-HDL cholesterol level of 92 mg per deciliter (2.38 mmol per liter), and a mean HDL cholesterol level of 40 mg per deciliter (1.03 mmol per liter). The patients were assigned to receive either 100 mg of anacetrapib once daily (15,225 patients) or matching placebo (15,224 patients). The primary outcome was the first major coronary event, a composite of coronary death, myocardial infarction, or coronary revascularization. RESULTS: During the median follow-up period of 4.1 years, the primary outcome occurred in significantly fewer patients in the anacetrapib group than in the placebo group (1640 of 15,225 patients [10.8%] vs. 1803 of 15,224 patients [11.8%]; rate ratio, 0.91; 95% confidence interval, 0.85 to 0.97; P=0.004). The relative difference in risk was similar across multiple prespecified subgroups. At the trial midpoint, the mean level of HDL cholesterol was higher by 43 mg per deciliter (1.12 mmol per liter) in the anacetrapib group than in the placebo group (a relative difference of 104%), and the mean level of non-HDL cholesterol was lower by 17 mg per deciliter (0.44 mmol per liter), a relative difference of -18%. There were no significant between-group differences in the risk of death, cancer, or other serious adverse events. CONCLUSIONS: Among patients with atherosclerotic vascular disease who were receiving intensive statin therapy, the use of anacetrapib resulted in a lower incidence of major coronary events than the use of placebo. (Funded by Merck and others; Current Controlled Trials number, ISRCTN48678192 ; ClinicalTrials.gov number, NCT01252953 ; and EudraCT number, 2010-023467-18 .)

A Perturbation-Based Methodology to Estimate the Equivalent Inertia of an Area Monitored by PMUs

This paper proposes a novel methodology to estimate equivalent inertia of an area, observed from its boundary buses where Phasor Measurement Units (PMUs) are assumed to be installed. The areas are divided according to the measurement points, and the methodology proposed can obtain the equivalent dynamic response of the area dependent of or independent of coherency of the generators inside, which is the first contribution of this paper. The methodology is divided in three parts: estimating the frequency response, estimating the power imbalance and estimating inertia through the solution of the swing equation by Least-Squares Method (LSM). The estimation of the power imbalance is the second contribution of this paper, enabling the study of areas that contain perturbations and attending the limitation of methods of the literature that rely on assumptions of slow mechanical power. It can be further divided in three steps: accounting the total power injected, estimating an equivalent load behavior and estimating an equivalent mechanical power. The quality of results is proved with test systems of different sizes, simulating different types of perturbations

Chapter Habitat and flora monitoring in the Regional Nature Reserve of "Palude del Conte e Duna Costiera di Porto Cesareo" (Puglia, Italy)

This study describes the results of the monitoring activity on habitats and plant species in the Regional Nature Reserve of "Palude del Conte e Duna Costiera di Porto Cesareo" (Puglia, Italy) and in the adjoining special areas of conservation (SACs), in the period April-December 2018. The activity combined field vegetation surveys and interpretation of orthophotos on a GIS system. The study identifies the pressure and threat factors that negatively affect the conservation of habitats

Enabling Technologies for Enhancing Power System Stability in the Presence of Converter-Interfaced Generators

The growing attention to environmental issues is leading to an increasing integration of renewable energy sources into electrical grids. This integration process could contribute to power system decarbonization, supporting the diversification of primary energy sources and enhancing the security of energy supply, which is threatened by the uncertain costs of conventional energy sources. Despite these environmental and economical benefits, many technological and regulatory problems should be fixed in order to significantly increase the level of penetration of renewable power generators, which are connected to power transmission and distribution systems via power electronic interfaces. Indeed, these converter-interfaced generators (CIGs) perturb grid operation, especially those fueled by non-programmable energy sources (e.g., wind and solar generators), affecting the system stability and making power systems more vulnerable to dynamic perturbations. To face these issues, the conventional operating procedures based on pre-defined system conditions, which are currently adopted in power system operation tools, should be enhanced in order to allow the “online” solution of complex decision-making problems, providing power system operators with the necessary measures and alerts to promptly adjust the system. A comprehensive analysis of the most promising research directions and the main enabling technologies for addressing this complex issue is presented in this paper