Modeling the Impact of Geomagnetically Induced Currents on Electrified Railway Signalling Systems in the United Kingdom

Patterson, Cameron; Wild, J. A.; Boteler, D. H.

doi:10.22541/essoar.167134688.89166284/v1

Cited by 2 publications

(2 citation statements)

References 12 publications

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“…Such substorm activity enhances the auroral electrojets (Gjerloev et al., 2004; Kamide & Nakamura, 1996) leading to intense magnetic field variations ( d B / d t ) on the ground (Freeman et al., 2019; Ngwira et al., 2018; Piccinelli & Krausmann, 2018; Viljanen et al., 2006). According to Faraday's law curl E = − d B / dt , such field variations couple with artificial conductors on the ground leading to the generation of geomagnetically induced currents (GICs) flowing in the conductors, which are detrimental to power infrastructure, oil/gas pipelines, and railway infrastructure (Molinski, 2002; Oliveira & Ngwira, 2017; Patterson et al., 2023; Piersanti & Carter, 2020; Pulkkinen et al., 2013; Smith et al., 2022; Thaduri et al., 2020; Tsurutani & Hajra, 2021).…”

Section: Introductionmentioning

confidence: 99%

Substorm‐Time Ground dB/dt Variations Controlled by Interplanetary Shock Impact Angles: A Statistical Study

Oliveira,

Weygand,

Coxon

et al. 2024

Space Weather

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In this study, we investigate the effects caused by interplanetary (IP) shock impact angles on the subsequent ground dB/dt variations during substorms. IP shock impact angles have been revealed as a major factor controlling the subsequent geomagnetic activity, meaning that shocks with small inclinations with the Sun‐Earth line are more likely to trigger higher geomagnetic activity resulting from nearly symmetric magnetospheric compressions. Such field variations are linked to the generation of geomagnetically induced currents (GICs), which couple to artificial conductors on the ground leading to deleterious consequences. We use a sub‐set of a shock data base with 237 events observed in the solar wind at L1 upstream of the Earth, and large arrays of ground magnetometers at stations located in North America and Greenland. The spherical elementary current system methodology is applied to the geomagnetic field data, and field‐aligned‐like currents in the ionosphere are derived. Then, such currents are inverted back to the ground and dB/dt variations are computed. Geographic maps are built with these field variations as a function of shock impact angles. The main findings of this investigation are: (a) typical dB/dt variations (5–10 nT/s) are caused by shocks with moderate inclinations; (b) the more frontal the shock impact, the more intense and the more spatially defined the ionospheric current amplitudes; and (c) nearly frontal shocks trigger more intense dB/dt variations with larger equatorward latitudinal expansions. Therefore, the findings of this work provide new insights for GIC forecasting focusing on nearly frontal shock impacts on the magnetosphere.

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Section: Introductionmentioning

confidence: 99%

Substorm‐Time Ground dB/dt Variations Controlled by Interplanetary Shock Impact Angles: A Statistical Study

Oliveira,

Weygand,

Coxon

et al. 2024

Space Weather

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“…Patterson et al. (2023) (from here on referred to as P23) conducted an initial investigation of how DC track circuit signaling systems on AC electrified railways in the UK are impacted by GICs. The study focused on the simplest case of misoperation, known as “right side” failures, which have the potential to cause disruption, but are not hazardous.…”

Section: Introductionmentioning

confidence: 99%

Modeling “Wrong Side” Failures Caused by Geomagnetically Induced Currents in Electrified Railway Signaling Systems in the UK

Patterson,

Wild,

Boteler

2023

Space Weather

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The majority of studies into space weather impacts on ground‐based systems focus on power supply networks and oil and gas pipelines. The effects on railway signaling infrastructure remain a sparsely covered aspect even though these systems are known to have experienced adverse effects in the past as a result of geomagnetic activity. This study extends recent modeling of geomagnetic effects on DC signaling for AC‐electrified railways in the UK that analyzed “right side” failures in which green signals are turned to red. The extended model reported here allows the study of “wrong side” failures where red signals are turned green: a failure mode that is potentially more dangerous. Railway lines using track circuit signaling, like those modeled in this study, are separated into a number of individual blocks. This study shows that a relay is most susceptible to “wrong side” failure when a train is at the end of a track circuit block. Assuming that each train is positioned at the end of the block it is occupying, the results show that the geoelectric field threshold at which “wrong side” failures can occur is lower than for “right side” failures. This misoperation field level occurs on a timescale of once every 10 or 20 years. We also show that the estimated electric field caused by a 1‐in‐100 years event could cause a significant number of “wrong side” failures at multiple points along the railway lines studied, although this depends on the number of trains on the line at that time.

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Modeling the Impact of Geomagnetically Induced Currents on Electrified Railway Signalling Systems in the United Kingdom

Cited by 2 publications

References 12 publications

Substorm‐Time Ground dB/dt Variations Controlled by Interplanetary Shock Impact Angles: A Statistical Study

Substorm‐Time Ground dB/dt Variations Controlled by Interplanetary Shock Impact Angles: A Statistical Study

Modeling “Wrong Side” Failures Caused by Geomagnetically Induced Currents in Electrified Railway Signaling Systems in the UK

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