scholarly journals Modelling natural electromagnetic interference in man-made conductors for space weather applications

2016 ◽  
Vol 34 (4) ◽  
pp. 427-436 ◽  
Author(s):  
Larisa Trichtchenko
Keyword(s):  
Exact Solution ◽  
Space Weather ◽  
Electromagnetic Interference ◽  
Geomagnetic Storms ◽  
Electromagnetic Properties ◽  
Electromagnetic Response ◽  
Frequency Range ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Variations ◽  
Wide Range

Abstract. Power transmission lines above the ground, cables and pipelines in the ground and under the sea, and in general all man-made long grounded conductors are exposed to the variations of the natural electromagnetic field. The resulting currents in the networks (commonly named geomagnetically induced currents, GIC), are produced by the conductive and/or inductive coupling and can compromise or even disrupt system operations and, in extreme cases, cause power blackouts, railway signalling mis-operation, or interfere with pipeline corrosion protection systems. To properly model the GIC in order to mitigate their impacts it is necessary to know the frequency dependence of the response of these systems to the geomagnetic variations which naturally span a wide frequency range. For that, the general equations of the electromagnetic induction in a multi-layered infinitely long cylinder (representing cable, power line wire, rail or pipeline) embedded in uniform media have been solved utilising methods widely used in geophysics. The derived electromagnetic fields and currents include the effects of the electromagnetic properties of each layer and of the different types of the surrounding media. This exact solution then has been used to examine the electromagnetic response of particular samples of long conducting structures to the external electromagnetic wave for a wide range of frequencies. Because the exact solution has a rather complicated structure, simple approximate analytical formulas have been proposed, analysed and compared with the results from the exact model. These approximate formulas show good coincidence in the frequency range spanning from geomagnetic storms (less than mHz) to pulsations (mHz to Hz) to atmospherics (kHz) and above, and can be recommended for use in space weather applications.

scholarly journals From solar eruption to transformer saturation: the space weather chain

2013 ◽  
Vol 8 (S300) ◽  
pp. 500-501
Author(s):  
Larisa Trichtchenko
Keyword(s):  
Space Weather ◽  
Geomagnetic Field ◽  
Geomagnetic Storms ◽  
Interplanetary Medium ◽  
Practical Importance ◽  
Power Grids ◽  
Geomagnetically Induced Currents ◽  
Large Space ◽  
Weather Events ◽  
Induced Currents

AbstractCoronal mass ejections (CME) and associated interplanetary-propagated solar wind disturbances are the established causes of the geomagnetic storms which, in turn, create the most hazardous impacts on power grids. These impacts are due to the large geomagnetically induced currents (GIC) associated with variations of geomagnetic field during storms, which, flowing through the transformer windings, cause extra magnetisation. That can lead to transformer saturation and, in extreme cases, can result in power blackouts. Thus, it is of practical importance to study the solar causes of the large space weather events. This paper presents the example of the space weather chain for the event of 5-6 November 2001 and a table providing complete overview of the largest solar events during solar cycle 23 with their subsequent effects on interplanetary medium and on the ground. This compact overview can be used as guidance for investigations of the solar causes and their predictions, which has a practical importance in everyday life.

The geoelectric structure of the Romanian underground and its contribution to the geoelectric hazard during the solar cycle 23

2020 ◽  
Author(s):  
Venera Dobrica ◽  
Dumitru Stanica ◽  
Crisan Demetrescu ◽  
Cristiana Stefan
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Storms ◽  
Geomagnetic Disturbance ◽  
Geoelectric Field ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Variations ◽  
European Continent ◽  
Field Recordings ◽  
Weather Events ◽  
Solar Cycle 23

<p>A recent model of the Romanian lithosphere electric properties, based on magnetotelluric transects carried out in the past 50 years across main tectonic units, is used to assess the geoelectric hazard represented by geomagnetically induced currents (GICs) for certain space weather events. Based on the geomagnetic field recordings and on information regarding the underground electric conductivity, the surface geoelectric field associated to geomagnetic variations during several large geomagnetic storms of the solar cycle 23 (1986-1996) is determined using the plane wave approximation for the depth propagation of the geomagnetic disturbance. A comparison to the territory of the European continent is done as well.   </p>

scholarly journals Observations from SANSA’s geomagnetic network during the Saint Patrick’s Day storm of 17–18 March 2015

2019 ◽  
Vol 115 (1/2) ◽  
Author(s):  
Emmanuel Nahayo ◽  
Pieter B. Kotzé ◽  
Pierre J. Cilliers ◽  
Stefan Lotz
Keyword(s):  
Electric Field ◽  
Space Weather ◽  
Power Distribution ◽  
Geomagnetic Storms ◽  
Geomagnetically Induced Currents ◽  
Weather Events ◽  
Induced Currents ◽  
Temporary Disturbance ◽  
Global And Local ◽  
Magnetic Observatories

Geomagnetic storms are space weather events that result in a temporary disturbance of the earth’s magnetosphere caused by a solar wind that interacts with the earth’s magnetic field. We examined more closely how some southern African magnetic observatories responded to the Saint Patrick’s Day storm using local K-indices. We show how this network of observatories may be utilised to model induced electric field, which is useful for the monitoring of geomagnetically induced anomalous currents capable of damaging power distribution infrastructure. We show an example of the correlation between a modelled induced electric field and measured geomagnetically induced currents in southern Africa. The data show that there are differences between global and local indices, which vary with the phases of the storm. We show the latitude dependence of geomagnetic activity and demonstrate that the direction of the variation is different for the X and Y components. Significance: • The importance of ground-based data in space weather studies is demonstrated. • We show how SANSA’s geomagnetic network may be utilised to model induced electric field, which is useful for the monitoring of geomagnetically induced anomalous currents capable of damaging power distribution infrastructure.

Towards the estimation of Space Weather-related corrosion on pipelines

2021 ◽  
Author(s):  
Larisa Trichtchenko
Keyword(s):  
Space Weather ◽  
Geomagnetic Storms ◽  
Pipeline Steel ◽  
Geomagnetically Induced Currents ◽  
Constant Frequency ◽  
Corrosion Rates ◽  
Weather Events ◽  
Continuous Frequency ◽  
The Times ◽  
Telluric Currents

<p>Geomagnetically induced currents (GIC), increased during space weather events, are able to interfere with pipeline corrosion protections systems and potentially can increase corrosion of the pipeline steel.</p><p>Methods, widely used for the evaluation of annual corrosion rates, are based on exposure of steel to constant currents and voltages (DC), or alternating currents and voltages of a constant frequency (50 Hz or 60 Hz), while GIC are characterised by a continuous frequency spectrum, with the range of frequencies from 10<sup>-5</sup> Hz to 1 Hz.</p><p>This paper introduces the methods for use in the estimation of corrosion rates on pipeline steel produced by GIC (commonly referred to as “telluric currents” in the pipeline industry) and provides results calculated for specific time periods with use of available recordings made on pipelines at the times of geomagnetic storms. As well, annual cumulative corrosion rates are estimated based on the modelling of pipeline currents and voltages.</p><p>In addition to the detailed presentation of the methods utilised, a comparison of corrosion rates produced by telluric variations on non-protected and protected pipelines located in mid- and high-latitudes is presented.</p>

scholarly journals Modelling geomagnetically induced currents in midlatitude Central Europe using a thin-sheet approach

2017 ◽  
Vol 35 (3) ◽  
pp. 751-761 ◽  
Author(s):  
Rachel L. Bailey ◽  
Thomas S. Halbedl ◽  
Ingrid Schattauer ◽  
Alexander Römer ◽  
Georg Achleitner ◽  
...  
Keyword(s):  
Power Systems ◽  
Geomagnetic Storms ◽  
Thin Sheet ◽  
Geoelectric Field ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Variations ◽  
Detailed Surface ◽  
Short Period ◽  
Long Time ◽  
Induced Currents

Abstract. Geomagnetically induced currents (GICs) in power systems, which can lead to transformer damage over the short and the long term, are a result of space weather events and geomagnetic variations. For a long time, only high-latitude areas were considered to be at risk from these currents, but recent studies show that considerable GICs also appear in midlatitude and equatorial countries. In this paper, we present initial results from a GIC model using a thin-sheet approach with detailed surface and subsurface conductivity models to compute the induced geoelectric field. The results are compared to measurements of direct currents in a transformer neutral and show very good agreement for short-period variations such as geomagnetic storms. Long-period signals such as quiet-day diurnal variations are not represented accurately, and we examine the cause of this misfit. The modelling of GICs from regionally varying geoelectric fields is discussed and shown to be an important factor contributing to overall model accuracy. We demonstrate that the Austrian power grid is susceptible to large GICs in the range of tens of amperes, particularly from strong geomagnetic variations in the east–west direction.

Variation Characteristics of Geoelectric Field in Mid-to-Low Latitude Area during Geomagnetic Storms

2014 ◽  
Vol 1008-1009 ◽  
pp. 524-529
Author(s):  
Ping Liu ◽  
Chun Ming Liu ◽  
Lian Guang Liu
Keyword(s):  
Power Systems ◽  
Space Weather ◽  
Transmission Lines ◽  
Geomagnetic Storms ◽  
System Component ◽  
Geoelectric Field ◽  
Geomagnetically Induced Currents ◽  
Low Latitude ◽  
Variation Characteristics ◽  
East West

Large geoelectric field generated in the ground during severe space weather events are sources of geomagnetically induced currents (GICs), which flow in power systems potentially causing damage to system component or failure of the system. In this paper, based on the H and D components of the recent geomagnetic storm data measured at 10 mid-to-low latitude geomagnetic observatories, we analyzed the variation characteristics of the amplitude of north-south and east-west geoelectric components with geographic latitudes. Furthermore, we discussed the possibilities of GIC problem occurrence in transmission lines in different directions at different latitude in China. The result shows that transmission lines in east-west direction at higher latitude are more susceptible to space weather hazard. And it will contribute to the assessment of geomagnetic hazard to power systems and the control of GIC in the current and future power grids in China.

scholarly journals Reproducibility of the Geomagnetically Induced Currents at Middle Latitudes During Space Weather Disturbances

2021 ◽  
Vol 8 ◽  
Author(s):  
Takashi Kikuchi ◽  
Yusuke Ebihara ◽  
Kumiko. K. Hashimoto ◽  
Kentaro Kitamura ◽  
Shin-Ichi Watari
Keyword(s):  
Space Weather ◽  
Linear Correlation ◽  
Geomagnetic Storms ◽  
Geomagnetic Latitude ◽  
Transverse Magnetic ◽  
Step Response ◽  
Quiet Time ◽  
Layer Model ◽  
Geomagnetically Induced Currents ◽  
Ionospheric Currents

Watari et al. (Space Weather, 2009, 7) found that the geomagnetically induced current (GIC) in Hokkaido, Japan (35.7° geomagnetic latitude (GML)), is well correlated with the y-component magnetic field (By) (correlation coefficients >0.8) and poorly correlated with Bx,z and dBx,y,z/dt. The linear correlation with By would help predict the GIC, if we have capabilities of reproducing the magnetosphere–ionosphere currents during space weather disturbances. To validate the linear correlation with By for any periods (T) of disturbances, we made correlation analyses for the geomagnetic sudden commencements and pulsations (T = 1–10 min), quasi-periodic DP2 fluctuations (30 min), substorm positive bays (60 min), geomagnetic storms (1–20 h), and quiet-time diurnal variations (8 h). The linear correlation is found to be valid for short periods (cc > 0.8 for T < 1 h) but not for long periods (cc < 0.3 for T > 6 h). To reproduce the GIC with any periods, we constructed one-layer model with uniform conductor and calculated the electric field (IEF) induced by By using the convolution of dBy/dt and the step response of the conductor. The IEF is found to be correlated with the GIC for long periods (cc > 0.9), while the GIC-By correlation remains better for short periods. To improve the model, we constructed a two-layer model with highly conductive upper and less conductive lower layers. The IEF is shown to reproduce the GIC with cc > 0.9 for periods ranging from 1 min to 24 h. The model is applied to the GIC measured at lower latitudes in Japan (25.3° GML) with strong By dependence. The mechanism of the strong By dependence of the GIC remains an issue, but a possible mechanism for the daytime GIC is due to the zeroth-order transverse magnetic (TM0) mode in the Earth-ionosphere waveguide, by which the ionospheric currents are transmitted from the polar to equatorial ionosphere.

scholarly journals Terahertz Optics of Materials with Spatially Harmonically Distributed Refractive Index

Materials ◽  
2020 ◽  
Vol 13 (22) ◽  
pp. 5208
Author(s):  
Dzmitry Bychanok ◽  
Gleb Gorokhov ◽  
Artyom Plyushch ◽  
Alfredo Ronca ◽  
Marino Lavorgna ◽  
...  
Keyword(s):  
Refractive Index ◽  
Thermoplastic Polyurethane ◽  
Electromagnetic Properties ◽  
Electromagnetic Response ◽  
Frequency Range ◽  
Spatially Periodic ◽  
3D Printed ◽  
New Generation ◽  
Analytical Expressions ◽  
Theoretical Results

The electromagnetic properties of structures with spatially periodic distributed graded refractive index were investigated in the terahertz frequency range. The band structure and electromagnetic response of material with harmonically distributed refractive index were calculated and analyzed. The analytical expressions for frequencies of the first and second bandgap are derived. 3D printed gyroid based architectures were proven to be harmonically graded refractive index structures with designed bandgaps in THz frequency ranges. The transmission coefficient of thermoplastic polyurethane-based samples were experimentally measured in the frequency range 100–500 GHz and compared with theoretical results. Due to losses in the real world produced samples, the predicted response is significantly dumped in the terahertz range and only traces of band gaps are experimentally observed. This funding paves the way toward a new generation of 3D printed THz components for gradient-index optics applications.

The quantification and possible sources of spatially structured and large amplitude geomagnetic depressions during strong geomagnetic storms measured by IMAGE

2021 ◽  
Author(s):  
Andrew Dimmock ◽  
Lisa Rosenqvist ◽  
Ari Viljanen ◽  
Colin Forsyth ◽  
Mervyn Freeman ◽  
...  
Keyword(s):  
Space Weather ◽  
Geomagnetic Storms ◽  
Dynamical Behaviour ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Disturbances ◽  
Modeling Framework ◽  
Coupling Dynamics ◽  
Weather Modeling ◽  
Induced Currents ◽  
Coupling Processes

<p>Geomagnetically Induced Currents (GICs) are a space weather hazard that can negatively impact large ground-based infrastructures such as power lines, pipelines, and railways. They are driven by the dynamic spatiotemporal behaviour of currents flowing in geospace, which drive rapid geomagnetic disturbances on the ground. In some cases, geomagnetic disturbances are highly localised and spatially structured due to the dynamical behaviour of geospace currents and magnetosphere-ionosphere (M-I) coupling dynamics, which are complex and often unclear.</p><p>In this work, we investigate and quantify the spatial structure of large geomagnetic depressions exceeding several hundred nT according to the 10 strongest events measured over Fennoscandia by IMAGE. Using ground magnetometer measurements we connect these spatially structured geomagnetic disturbances to possible M-I coupling processes and identify their likely magnetospheric origin. In addition, the ability for these disturbances to drive large GICs is assessed by calculating their respective geoelectric fields in Sweden using the SMAP ground conductivity model. To compliment the observations, we also utilise high resolution runs (>7 million cells) of the Space Weather Modeling Framework (SWMF) to determine to what extent global MHD models can capture this behaviour.</p>

scholarly journals North Europe power transmission system vulnerability during extreme space weather

2018 ◽  
Vol 8 ◽  
pp. A03 ◽  
Author(s):  
Roberta Piccinelli ◽  
Elisabeth Krausmann
Keyword(s):  
Space Weather ◽  
Power Transmission ◽  
Geomagnetic Storms ◽  
Extreme Event ◽  
Transmission System ◽  
Mitigation Measures ◽  
Geomagnetically Induced Currents ◽  
Power Transmission System ◽  
Induced Currents ◽  
The Impact

Space weather driven by solar activity can induce geomagnetic disturbances at the Earth's surface that can affect power transmission systems. Variations in the geomagnetic field result in geomagnetically induced currents that can enter the system through its grounding connections, saturate transformers and lead to system instability and possibly collapse. This study analyzes the impact of extreme space weather on the northern part of the European power transmission grid for different transformer designs to understand its vulnerability in case of an extreme event. The behavior of the system was analyzed in its operational mode during a severe geomagnetic storm, and mitigation measures, like line compensation, were also considered. These measures change the topology of the system, thus varying the path of geomagnetically induced currents and inducing a local imbalance in the voltage stability superimposed on the grid operational flow. Our analysis shows that the North European power transmission system is fairly robust against extreme space weather events. When considering transformers more vulnerable to geomagnetic storms, only few episodes of instability were found in correspondence with an existing voltage instability due to the underlying system load. The presence of mitigation measures limited the areas of the network in which bus voltage instabilities arise with respect to the system in which mitigation measures are absent.

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