Eco-sustainable routing of power lines for the connection of renewable energy plants to the Italian high-voltage grid

Routing of high-voltage electric transmission lines for the connection of renewable energy-distributed generation plants is a critical issue from an environmental point of view. A standard methodology that accounts for multiple perspectives, influence factors and is able to mediate between weighted constraints can be a useful tool for the regulating bodies that are involved in approval processes. The methodology can be an effective support to increase reliability, save consumers' money and mitigate the unavoidable impacts of the lines on the population living nearby. In this paper we investigate the suitability of a procedure employed by Terna, the Italian high-voltage transmission system operator, to identify the corridors where to route new overhead transmission lines with the lowest environmental impact. The methodology is based on the subdivision of all the relevant constraints dictated by environmental issues and territory legislations in four main classes. A real case study concerning the design and connection of a wind farm placed near Collarmele, in the center of Italy, shows the effectiveness of the proposed methodology

Reliability Engineering Methods for Distribution Systems - Influence of Differences between Cable Systems and Overhead Lines

One way to increase distribution network reliability is to replace traditional overhead lines with underground cables. To fully utilize these investments, network owners will have to adjust their reliability engineering methods to suit the new cable networks. In this paper different condition assessment methods as well as improved failure statistics for cable systems are considered. The paper is based on information from project reports and scientific papers. In addition a number of Swedish distribution network owners have been asked to share their opinion of reliability engineering work of today and the future. The methods used for distribution system condition assessment change as overhead lines are replaced by underground cable. Visual inspections can no longer be used and diagnostic methods are instead introduced. The diagnostic methods are costly to perform. To become frequently used they must prove to be efficient enough to justify the financial means required. New, improved, diagnostic methods are under development and since most cable failures are related to component properties the use of diagnostic methods is likely to increase. Statistics show that a majority of the cable system failures are ageing failures. The ageing failures do not to any large extent depend on environmental factors but on component properties. This implies that component lifetime standard deviation decreases as component data are related to the statistics, yet failure statistics is at present not related to component data. A majority of the network owners contributing to this paper agree that the nature of cable failures, except excavation failures, makes it interesting and useful to related cable data to failure statistics and to share the statistics with other network owners. Several Swedish distribution network owners are in the process of installing new program for network analysis. One challenge is to decide which component data that shall be related to the failure statistics. Operational age, maintenance history, manufacturer and year of manufacturer are four manageable factors which influence on failure statistics is already established but yet not thoroughly evaluated. In addition the method of cable excavation is suggested as a fifth interesting factor related to cable system reliability

Automated classification of three-dimensional reconstructions of coral reefs using convolutional neural networks

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Hopkinson, B. M., King, A. C., Owen, D. P., Johnson-Roberson, M., Long, M. H., & Bhandarkar, S. M. Automated classification of three-dimensional reconstructions of coral reefs using convolutional neural networks. PLoS One, 15(3), (2020): e0230671, doi: 10.1371/journal.pone.0230671.Coral reefs are biologically diverse and structurally complex ecosystems, which have been severally affected by human actions. Consequently, there is a need for rapid ecological assessment of coral reefs, but current approaches require time consuming manual analysis, either during a dive survey or on images collected during a survey. Reef structural complexity is essential for ecological function but is challenging to measure and often relegated to simple metrics such as rugosity. Recent advances in computer vision and machine learning offer the potential to alleviate some of these limitations. We developed an approach to automatically classify 3D reconstructions of reef sections and assessed the accuracy of this approach. 3D reconstructions of reef sections were generated using commercial Structure-from-Motion software with images extracted from video surveys. To generate a 3D classified map, locations on the 3D reconstruction were mapped back into the original images to extract multiple views of the location. Several approaches were tested to merge information from multiple views of a point into a single classification, all of which used convolutional neural networks to classify or extract features from the images, but differ in the strategy employed for merging information. Approaches to merging information entailed voting, probability averaging, and a learned neural-network layer. All approaches performed similarly achieving overall classification accuracies of ~96% and >90% accuracy on most classes. With this high classification accuracy, these approaches are suitable for many ecological applications.This study was funded by grants from the Alfred P. Sloan Foundation (BMH, BR2014-049; https://sloan.org), and the National Science Foundation (MHL, OCE-1657727; https://www.nsf.gov). The funders had no role in the study design, data collection and analysis, decision to publish, or preparation of the manuscript

Fatigue analysis of catenary contact wires for high speed trains

The fatigue fracture is one of the most critical failures which may occur on the high speed network because it is undetectable and it has a huge impact on traffic disruption. The contact wire lifespan of a high speed line is estimated at more than 50 years and thus it is necessary to consider the risk of fatigue. The Railway Technical Research Institute in Japan studied this phenomenon for a long time and performed experimental tests. Using these results and by comparing with failures occurred in France, a preliminary analysis is carried out to identify parameters which significantly influence the fatigue phenomenon. This analysis consists in using the numerical software OSCAR© to evaluate the loads, perform a fatigue assessment of the contact wire. The procedure, using a one-dimensional and a three-dimensional model, is described in this article

How to increase cross border transmission capacity? A case study: Belgium.

Cross border capacity allows electric energy to be traded internationally. The electricity sector used to be vertically integrated and often state-owned. High voltage grids were generally developed within the borders of a country. Connecting different national high voltage grids was done to improve the security of the system and to accomodate for a few historical long term contracts. By doing so, the different systems could share their reserve generation capacity. Since the liberalization of the electricity sector, cross border capacity has gained a renewed interest as this can increase the competition in the market. This paper aims to give an overview of recent and planned investments which increase the cross border capacity of Belgium. Also we give an insight into the different technologies which can be used and their advantages and drawbacks are discussed.

Conceptual design study for an advanced cab and visual system, volume 2

The performance, design, construction and testing requirements are defined for developing an advanced cab and visual system. The rotorcraft system integration simulator is composed of the advanced cab and visual system and the rotorcraft system motion generator, and is part of an existing simulation facility. User's applications for the simulator include rotorcraft design development, product improvement, threat assessment, and accident investigation