scholarly journals On the Use of LoRa Technology for Logic Selectivity in MV Distribution Networks

Energies ◽  
2018 ◽  
Vol 11 (11) ◽  
pp. 3079 ◽  
Author(s):  
Leopoldo Angrisani ◽  
Francesco Bonavolontà ◽  
Annalisa Liccardo ◽  
Rosario Schiano Lo Moriello

In this paper, a logic selectivity system based on Long Range (LoRa) technology for the protection of medium-voltage (MV) networks is proposed. The development of relays that communicate with each other using LoRa allows for the combination of the cost-effectiveness and ease of installation of wireless networks with long-range coverage and reliability. The realized demonstrator to assess the proposed system is also presented in the paper; based on different types of faults and different locations, the times needed for clearing a fault and restoring the network were estimated from repeated experiments. The obtained results confirm that, with an optimized design of transmitted packets and of protocol characteristics, LoRa communication grants fault management that meets the criteria of logic selectivity, with fault isolation occurring within the maximum allowed time.

2004 ◽  
Vol 14 (5) ◽  
pp. 931-937 ◽  
Author(s):  
W. A. A. Tjalma ◽  
P. A. Van Dam ◽  
A. P. Makar ◽  
D. J. Cruickshank

The aim of the present article was to evaluate the cost-effectiveness of follow-up in endometrial cancer patients. A literature review was performed regarding the studies that addressed routine follow-up of endometrial cancer. For each published study, the costs of the follow-up program were calculated according to Belgium standards. A mean total of 13% relapsed. Symptomatology and clinical examination detected over 83% of the recurrences. The follow-up cost in euro after 5 and 10 years ranged between 127.68 and 2028.78 and between 207.48 and 2353.48, respectively. Based on the available data, there is little evidence of routine follow-up improving survival rates. Multiple protocols are used in practice without an evidence base. There is an urgent need for prospective randomized studies to evaluate the value of the current so-called ‘standard medical practice of follow-up.’ It is to be expected that the cost of follow-up could be reduced considerably, for instance, by tailoring to low- and high-risk groups, or by abandoning routine follow-up. Symptomatic patients, however, should be evaluated immediately. A reduction in the number of visits and examinations would mean an enormous reduction in costs. This economic benefit would be warmly welcomed in the times of increased health costs and decreased budgets.


Energies ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2874
Author(s):  
Édison Massao Motoki ◽  
José Maria de Carvalho Filho ◽  
Paulo Márcio da Silveira ◽  
Natanael Barbosa Pereira ◽  
Paulo Vitor Grillo de Souza

The objective of this work is to propose and apply a methodology to obtain the cost of industrial process shutdowns due to voltage sag and short interruption. A field survey, aided by a specific questionnaire, was carried out in several industries connected to medium voltage networks, in the states of Espírito Santo and São Paulo in Brazil. The results obtained were the costs per event and the costs per demand in a total of 33 companies in 12 different types of activities. It is noteworthy that this survey brings a relevant technical contribution to the electricity sector, helping to fill, even partially, an existing gap in both national and international literature.


Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3759 ◽  
Author(s):  
Farughian ◽  
Kumpulainen ◽  
Kauhaniemi

In this paper, a new method for locating single-phase earth faults on non-effectively earthed medium voltage distribution networks is proposed. The method requires only current measurements and is based on the analysis of the negative sequence components of the currents measured at secondary substations along medium voltage (MV) distribution feeders. The theory behind the proposed method is discussed in depth. The proposed method is examined by simulations, which are carried out for different types of networks. The results validate the effectiveness of the method in locating single-phase earth faults. In addition, some aspects of practical implementation are discussed. A brief comparative analysis is conducted between the behaviors of negative and zero sequence currents along a faulty feeder. The results reveal a considerably higher stability level of the negative sequence current over that of the zero sequence current.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Abdelrahman M. Farouk ◽  
Rahimi A. Rahman ◽  
Noor Suraya Romali

Purpose Sustainable water management has been a trending goal in the past decade. Non-revenue water (NRW) is one form of water loss that should be addressed to reach water sustainability. While rehabilitating water distribution networks (WDNs) is one way to decrease NRW, the process is often delayed owing to cost. Therefore, it is essential to provide decision-makers with cost-effective approaches to optimize WDN rehabilitation. This study aims to evaluate the cost-effectiveness of approaches for rehabilitating WDN from developing countries’ perspectives. Design/methodology/approach A systematic literature review was first conducted to identify different WDN rehabilitation methods and techniques to develop the questionnaire survey. This is followed by collecting questionnaire survey data in Malaysia and Egypt on the cost and effectiveness of the WDN rehabilitation methods and techniques. A total of 176 respondents were collected, 109 from Malaysia and 67 from Egypt. Then, the data were analyzed using mean score ranking with normalization technique and agreement analysis. Findings The results from the data analysis show that the cost-effective approaches are “programming,” “simulation,” “digital twin” and “supervisory control and data acquisition.” Additionally, the data from Malaysia suggest two additional cost-effective approaches: “zoning network” and “genetic algorithm.” Originality/value To the best of the authors’ knowledge, this paper presents one of the first studies that laterally compares the cost-effectiveness of existing and potential WDN rehabilitation approaches between different countries. There is yet a study that compared these WDN rehabilitation approaches. This comparison which is developed depending on the systematic review could be a reference for future studies or surveys which could be done on different countries in the future. The main findings of this paper can be a useful reference for decision-makers, especially those from middle-income countries, when looking into approaches for WDN rehabilitation. A better WDN rehabilitation supports NRW reduction, moving towards sustainable water management.


2013 ◽  
Vol 416-417 ◽  
pp. 385-389 ◽  
Author(s):  
Mu Chen ◽  
K.T. Chau ◽  
Wen Long Li ◽  
Chun Hua Liu

This paper presents a quantitative comparison between the non-rare-earth permanent magnet (PM) and rare-earth PM based linear magnetic gear. By using the finite element analysis, three linear magnetic gears adopting either the non-rare-earth PM or rare-earth PM are analyzed and discussed. Hence, the cost-effectiveness comparison among different types of PMs is conducted. The results indicate that the non-rare-earth PM is preferred to the rare-earth PM for application to linear magnetic gears when cost-effectiveness is emphasized.


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