Multiconductor Cell Analysis of AC High Speed Railway Lines

The aim of this article is the application of Multiconductor Cell Analysis (MCA) to a very special case of a multiconductor system, i.e., the AC high-speed railway system, with 14 parallel conductors. The present matrix approach allows representing both the single elements and the entire railway system also including the high-voltage (HV) three-phase supply network. The algorithm allows computing all the steady-state regime electrical quantities (voltages, currents, and power) of each section: in particular, the ground return current, responsible for electromagnetic interferences (EMIs), can be derived by the knowledge of all the circulating currents. It is also possible to evaluate the electric unbalance impact on the supply three-phase power system given by the railway system. Eventually, two different scenarios are presented, i.e., a maximum allowable high-speed line power request and a contact-wire-to-rail short circuit

A Novel AC/DC Power Flow: HVDC-LCC/VSC Inclusion Into the PFPD Bus Admittance Matrix

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Immunology and Homeopathy. 4. Clinical Studies—Part 1

The evidence-based research of the effectiveness of homeopathic medicines in common immunologic disorders is reviewed. In part 1, we introduce methodological issues of clinical research in homeopathy, and criteria utilized to evaluate the literature. Then 24 studies (12 randomized and 12 non-randomized) on common upper respiratory tract infections and otorhinolaryngologic complaints are described. In part 2, the focus will be on allergic diseases and the effectiveness of homeopathy will be globally evaluated and discussed using the criteria of evidence-based medicine

A Three-Phase Power-Flow Algorithm for Transmission Networks: a Hybrid Phase/Sequence Approach

In this paper, the three-phase generalization of a single-phase power flow (named PFPD) developed by the first author is presented. This three-phase formulation is chiefly conceived for HV/EHV transmission network applications, but it preserves a general validity for any power system. An iterative method for the solution achievement is throughout expounded. The algorithm quantitatively aims at investigating the impact of the asymmetrical transmission structures on power systems. This impact is evaluated in terms of voltage and current sequence components. Moreover, discussions on possible improvement actions to enhance the power quality are developed. The algorithm is implemented in Matlab environment and tested by several fictitious networks. Eventually, extensive comparisons in terms of execution time, number of iterations and solution accuracy with the software DIgSILENT PowerFactory are presented

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

Results From the Cuore Experiment †

The Cryogenic Underground Observatory for Rare Events (CUORE) is the first bolometric experiment searching for neutrinoless double beta decay that has been able to reach the 1-ton scale. The detector consists of an array of 988 TeO2 crystals arranged in a cylindrical compact structure of 19 towers, each of them made of 52 crystals. The construction of the experiment was completed in August 2016 and the data taking started in spring 2017 after a period of commissioning and tests. In this work we present the neutrinoless double beta decay results of CUORE from examining a total TeO2 exposure of 86.3kg yr, characterized by an effective energy resolution of 7.7 keV FWHM and a background in the region of interest of 0.014 counts/ (keV kg yr). In this physics run, CUORE placed a lower limit on the decay half- life of neutrinoless double beta decay of 130Te \u3e 1.3.1025 yr (90% C. L.). Moreover, an analysis of the background of the experiment is presented as well as the measurement of the 130Te 2 &nuββ decay with a resulting half- life of T 2v 1/2 = [7.9 ±0.1 (stat.) ±0.2 (syst.)] x 1020 yr which is the most precise measurement of the half- life and compatible with previous results