{"title":"Comments on the high-frequency response of hemispherical grounding electrodes with emphasis on magnetic induction effects","authors":"","doi":"10.1016/j.epsr.2024.111100","DOIUrl":null,"url":null,"abstract":"<div><div>Accurate calculation of electrodes’ impedance is of major importance for the operation and protection of overhead power lines whose towers are periodically bonded to earth via grounding electrodes; particularly when the towers are hit by lightning discharges. A recent paper has proposed a simple RC-circuit to model the frequency response of hemispherical electrodes which predicts a continuous decrease to zero in electrode impedance as the frequency increases. The prediction agrees with the model, but the model is not sound and, therefore, the prediction is disputable. We show that the model is inadequate because it is founded on the conviction that the magnetic field is zero everywhere inside the soil <sup>___</sup>which we claim is a mistake. We employ a full-wave FEM solver to recalculate the numerical results presented in that paper and observed a notable disagreement for high frequencies. In addition, we also show how the problem of calculating the impedance of hemispherical grounding systems can be solved, encompassing displacement-current effects and magnetic-field effects.</div></div>","PeriodicalId":50547,"journal":{"name":"Electric Power Systems Research","volume":null,"pages":null},"PeriodicalIF":3.3000,"publicationDate":"2024-09-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.sciencedirect.com/science/article/pii/S0378779624009854/pdfft?md5=e44ae86fce0890d1c0b95ce7695fae23&pid=1-s2.0-S0378779624009854-main.pdf","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Electric Power Systems Research","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0378779624009854","RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"ENGINEERING, ELECTRICAL & ELECTRONIC","Score":null,"Total":0}
引用次数: 0
Abstract
Accurate calculation of electrodes’ impedance is of major importance for the operation and protection of overhead power lines whose towers are periodically bonded to earth via grounding electrodes; particularly when the towers are hit by lightning discharges. A recent paper has proposed a simple RC-circuit to model the frequency response of hemispherical electrodes which predicts a continuous decrease to zero in electrode impedance as the frequency increases. The prediction agrees with the model, but the model is not sound and, therefore, the prediction is disputable. We show that the model is inadequate because it is founded on the conviction that the magnetic field is zero everywhere inside the soil ___which we claim is a mistake. We employ a full-wave FEM solver to recalculate the numerical results presented in that paper and observed a notable disagreement for high frequencies. In addition, we also show how the problem of calculating the impedance of hemispherical grounding systems can be solved, encompassing displacement-current effects and magnetic-field effects.
期刊介绍:
Electric Power Systems Research is an international medium for the publication of original papers concerned with the generation, transmission, distribution and utilization of electrical energy. The journal aims at presenting important results of work in this field, whether in the form of applied research, development of new procedures or components, orginal application of existing knowledge or new designapproaches. The scope of Electric Power Systems Research is broad, encompassing all aspects of electric power systems. The following list of topics is not intended to be exhaustive, but rather to indicate topics that fall within the journal purview.
• Generation techniques ranging from advances in conventional electromechanical methods, through nuclear power generation, to renewable energy generation.
• Transmission, spanning the broad area from UHV (ac and dc) to network operation and protection, line routing and design.
• Substation work: equipment design, protection and control systems.
• Distribution techniques, equipment development, and smart grids.
• The utilization area from energy efficiency to distributed load levelling techniques.
• Systems studies including control techniques, planning, optimization methods, stability, security assessment and insulation coordination.