Using PC indices to predict violent GIC events threatening power grids

The aim of the present contribution is to investigate the timing relations between enhancements in the Polar Cap (PC) indices and power grid disturbances related to geomagnetically induced currents (GIC). The polar cap indices, PCN (North) and PCS (South), are based on measurements of geomagnetic variations in the central polar caps. These variations are strongly related to the transpolar convection of plasma and magnetic fields driven by the solar wind. During cases of enhanced merging processes at the front of the magnetosphere and subsequent tailward convection of plasma and embedded magnetic fields, the magnetospheric tail configuration may accumulate excess energy, which upon release may cause violent substorm activity. Earlier reports have disclosed remarkably lengthy intervals, ranging up to several hours, of elevated PC index values preceding GIC-related power grid disruptions. The present investigation has shown that the delays of typically 3–4 h between increases in the PC indices and GIC-related power grid disturbances are related to displacements of the substorm processes responsible for strong GIC events to subauroral latitudes where vulnerable power grids reside. The results have shown that PC index values remaining above an “alert level” of 10 mV/m through more than 1 h indicate a high risk for violent GIC events that may threaten power grids and other vulnerable technical systems. These results support the application of real-time PC indices in space weather monitoring and forecast services.

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Prediction of geomagnetically induced currents (GICs) flowing in Japanese power grid for Carrington-class magnetic storms

Earth Planets and Space ◽

10.1186/s40623-021-01493-2 ◽

2021 ◽

Vol 73 (1) ◽

Author(s):

Yusuke Ebihara ◽

Shinichi Watari ◽

Sandeep Kumar

Keyword(s):

Transmission Lines ◽

Power Grid ◽

Magnetic Storms ◽

Power Grids ◽

Geomagnetically Induced Currents ◽

Geomagnetic Disturbances ◽

Low Latitude ◽

Solar Eruptions ◽

Induced Currents ◽

Extra High Voltage

AbstractLarge-amplitude geomagnetically induced currents (GICs) are the natural consequences of the solar–terrestrial connection triggered by solar eruptions. The threat of severe damage of power grids due to the GICs is a major concern, in particular, at high latitudes, but is not well understood as for low-latitude power grids. The purpose of this study is to evaluate the lower limit of the GICs that could flow in the Japanese power grid against a Carrington-class severe magnetic storm. On the basis of the geomagnetic disturbances (GMDs) observed at Colaba, India, during the Carrington event in 1859, we calculated the geoelectric disturbances (GEDs) by a convolution theory, and calculated GICs flowing through transformers at 3 substations in the Japanese extra-high-voltage (500-kV) power grid by a linear combination of the GEDs. The estimated GEDs could reach ~ 2.5 V/km at Kakioka, and the GICs could reach, at least, 89 ± 30 A near the storm maximum. These values are several times larger than those estimated for the 13–14 March 1989 storm (in which power blackout occurred in Canada), and the 29–31 October 2003 storm (in which power blackout occurred in Sweden). The GICs estimated here are the lower limits, and there is a probability of stronger GICs at other substations. The method introduced here will be immediately applicable for benchmark evaluation of low-latitude GICs against the Carrington-class magnetic storms if one assumes electrical parameters, such as resistance of transmission lines, with sufficient accuracy.

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Resonant Inverse Compton Scattering above Polar Caps: Gap Acceleration Efficiency for Young Pulsars

Publications of the Astronomical Society of Australia ◽

10.1071/as98222 ◽

1998 ◽

Vol 15 (2) ◽

pp. 222-227 ◽

Cited By ~ 3

Author(s):

Qinghuan Luo ◽

R. J. Protheroe

Keyword(s):

Magnetic Fields ◽

Energy Loss ◽

Compton Scattering ◽

Effective Temperature ◽

Polar Cap ◽

Inverse Compton Scattering ◽

Polar Caps ◽

High Acceleration ◽

Inverse Compton ◽

Polar Gap

AbstractIt is shown that for moderately hot polar caps (with effective temperature of ∼106 K), the efficiency of polar gap acceleration is lower compared to the case in which the polar caps are relatively cool and inverse Compton scattering plays no role in controlling the gap. For young pulsars with superstrong magnetic fields (≥109 T) and hot polar caps (with temperature of ≥5 × 106 K), because of the energy loss of electrons or positrons due to resonant inverse Compton scattering in the vicinity of polar caps, pair cascades occur at distances further away from the polar cap, and in this case we have a relatively high acceleration efficiency, with ions carrying most of the particle luminosity.

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The Role of Global/Regional Earth Conductivity Models in Natural Geomagnetic Hazard Mitigation

Surveys in Geophysics ◽

10.1007/s10712-019-09579-z ◽

2019 ◽

Vol 41 (1) ◽

pp. 115-166 ◽

Cited By ~ 7

Author(s):

Anna Kelbert

Keyword(s):

Electrical Conductivity ◽

Electric Power ◽

Power Grid ◽

Geomagnetic Disturbance ◽

Power Grids ◽

Geomagnetically Induced Currents ◽

Geomagnetic Disturbances ◽

Entry Points ◽

Electric Power Grids ◽

Submarine Cables

AbstractGeomagnetic disturbances cause perturbations in the Earth’s magnetic field which, by the principle of electromagnetic induction, in turn cause electric currents to flow in the Earth. These geomagnetically induced currents (GICs) also enter man-made technological conductors that are grounded; notably, telegraph systems, submarine cables and pipelines, and, perhaps most significantly, electric power grids, where transformer groundings at power grid substations serve as entry points for GICs. The strength of the GICs that flow through a transformer depends on multiple factors, including the spatiotemporal signature of the geomagnetic disturbance, the geometry and specifications of the power grid, and the electrical conductivity structure of the Earth’s subsurface. Strong GICs are hazardous to power grids and other infrastructure; for example, they can severely damage transformers and thereby cause extensive blackouts. Extreme space weather is therefore hazardous to man-made technologies. The phenomena of extreme geomagnetic disturbances, including storms and substorms, and their effects on human activity are commonly referred to as geomagnetic hazards. Here, we provide a review of relevant GIC studies from around the world and describe their common and unique features, while focusing especially on the effects that the Earth’s electrical conductivity has on the GICs flowing in the electric power grids.

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Extreme value analysis of the time derivative of the horizontal magnetic field and computed electric field

Annales Geophysicae ◽

10.5194/angeo-34-485-2016 ◽

2016 ◽

Vol 34 (4) ◽

pp. 485-491 ◽

Cited By ~ 6

Author(s):

Peter Wintoft ◽

Ari Viljanen ◽

Magnus Wik

Keyword(s):

Magnetic Fields ◽

Time Derivative ◽

Extreme Value ◽

Power Grids ◽

Extreme Value Analysis ◽

Geomagnetically Induced Currents ◽

Horizontal Magnetic Field ◽

Value Analysis ◽

Electrical Fields ◽

Ground Magnetic

Abstract. High-frequency ( ≈ minutes) variability of ground magnetic fields is caused by ionospheric and magnetospheric processes driven by the changing solar wind. The varying magnetic fields induce electrical fields that cause currents to flow in man-made conductors like power grids and pipelines. Under extreme conditions the geomagnetically induced currents (GIC) may be harmful to the power grids. Increasing our understanding of the extreme events is thus important for solar-terrestrial science and space weather. In this work 1-min resolution of the time derivative of measured local magnetic fields (|dBh∕dt|) and computed electrical fields (Eh), for locations in Europe, have been analysed with extreme value analysis (EVA). The EVA results in an estimate of the generalized extreme value probability distribution that is described by three parameters: location, width, and shape. The shape parameter controls the extreme behaviour. The stations cover geomagnetic latitudes from 40 to 70° N. All stations included in the study have contiguous coverage of 18 years or more with 1-min resolution data. As expected, the EVA shows that the higher latitude stations have higher probability of large |dBh∕dt| and |Eh| compared to stations further south. However, the EVA also shows that the shape of the distribution changes with magnetic latitude. The high latitudes have distributions that fall off faster to zero than the low latitudes, and upward bounded distributions can not be ruled out. The transition occurs around 59–61° N magnetic latitudes. Thus, the EVA shows that the observed series north of ≈ 60° N have already measured values that are close to the expected maxima values, while stations south of ≈ ° N will measure larger values in the future.

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Effect of the Earth’s lateral conductivity variations on geomagnetically induced currents in power grids

International Journal of Electrical Power & Energy Systems ◽

10.1016/j.ijepes.2021.107148 ◽

2021 ◽

Vol 132 ◽

pp. 107148

Author(s):

Xuan Wang ◽

Chunming Liu ◽

Zhouming Kang

Keyword(s):

Power Grids ◽

Geomagnetically Induced Currents ◽

Induced Currents

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Polar caps and auroral zones under idealized axisymmetric magnetic fields

Advances in Space Research ◽

10.1016/j.asr.2021.02.003 ◽

2021 ◽

Vol 67 (10) ◽

pp. 3228-3236

Author(s):

Angel O.U. Parentis ◽

Bruno S. Zossi ◽

Hagay Amit ◽

Ana G. Elias

Keyword(s):

Magnetic Fields ◽

Polar Caps

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POWER GRIDS ANALYSIS IN COMPRESSED KRYLOV-SUBSPACE METHODS

Journal of Circuits System and Computers ◽

10.1142/s0218126608004435 ◽

2008 ◽

Vol 17 (03) ◽

pp. 439-446

Author(s):

HAOHANG SU ◽

YIMEN ZHANG ◽

YUMING ZHANG ◽

JINCAI MAN

Keyword(s):

Present Method ◽

Large Scale ◽

Krylov Subspace ◽

Power Grid ◽

Excellent Result ◽

Krylov Subspace Methods ◽

Power Grids ◽

Improved Method ◽

Subspace Methods ◽

Transient Simulations

An improved method is proposed based on compressed and Krylov-subspace iterative approaches to perform efficient static and transient simulations for large-scale power grid circuits. It is implemented with CG and BiCGStab algorithms and an excellent result has been obtained. Extensive experimental results on large-scale power grid circuits show that the present method is over 200 times faster than SPICE3 and around 10–20 times faster than ICCG method in transient simulations. Furthermore, the presented algorithm saves the memory usage over 95% of SPICE3 and 75% of ICCG method, respectively while the accuracy is not compromised.

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Analytical and experimental discussion of a circuit-based model for compact fluorescent lamps in a 60Hz power grid

Ingeniería e Investigación ◽

10.15446/ing.investig.v35n1sup.53618 ◽

2015 ◽

Vol 35 (1Sup) ◽

pp. 89-97 ◽

Cited By ~ 2

Author(s):

Gabriel Alexis Malagon ◽

Jeisson Bello Peña ◽

Gabriel Ordóñez Plata ◽

Cesar Duarte Gualdrón

Keyword(s):

Scientific Literature ◽

Power Grid ◽

Research Work ◽

Power Grids ◽

Voltage Source ◽

Electrical System ◽

Font Size ◽

Stroke Width ◽

Fluorescent Lamps ◽

Compact Fluorescent Lamps

This article presents an analysis and discussion on the performance of a circuit-based model for Compact Fluorescent Lamps (CFL) in a 120V 60Hz power grid. This model is proposed and validated in previous scientific literature for CFLs in 230V 50Hz systems. Nevertheless, the derivation of this model is not straightforward to follow and its performance in 120V 60Hz systems is a matter of research work. In this paper, the analytical derivation of this CFL model is presented in detail and its performance is discussed when predicting the current of a CFL designed to operate in a 120V 60Hz electrical system. The derived model is separately implemented in both MATLAB® and ATP-EMTP® software using two different sets of parameters previously proposed for 230V 50Hz CFLs. These simulation results are compared against laboratory measurements using a programmable AC voltage source. The measurements and simulations considered seven CFLs 110/127V 60Hz with different power ratings supplied by a sinusoidal (not distorted) voltage source. The simulations under these conditions do not properly predict the current measurements and therefore the set of parameters and/or the model itself need to be adjusted for 120V 60Hz power grids.<br style="font-style: normal; font-variant: normal; font-weight: normal; letter-spacing: normal; line-height: normal; orphans: 2; text-align: -webkit-auto; text-indent: 0px; text-transform: none; white-space: normal; widows: 2; word-spacing: 0px; -webkit-text-size-adjust: auto; -webkit-text-stroke-width: 0px;" />

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Evaluation of the geometry of ionospheric current systems related to rapid geomagnetic variations

Annales Geophysicae ◽

10.5194/angeo-22-63-2004 ◽

2004 ◽

Vol 22 (1) ◽

pp. 63-72 ◽

Cited By ~ 8

Author(s):

S. V. Apatenkov ◽

V. A. Sergeev ◽

R. Pirjola ◽

A. Viljanen

Keyword(s):

Dynamic Pressure ◽

Auroral Oval ◽

Auroral Zone ◽

Middle Part ◽

Magnetic Storms ◽

Geomagnetically Induced Currents ◽

Geomagnetic Variations ◽

Ionospheric Current ◽

Solar Wind Parameters ◽

Current Systems

Abstract. To learn about the geometry and sources of the ionospheric current systems which generate strong geomagnetically induced currents, we categorize differential equivalent current systems (DEC) for events with strong dB/dt by decomposing them into the contributions of electrojet-type and vortex-type elementary systems. By solving the inverse problem we obtain amplitudes and locations of these elementary current systems. One-minute differences of the geomagnetic field values at the IMAGE magnetometer network in 1996–2000 are analysed to study the spatial distributions of large dB/dt events. The relative contributions of the two components are evaluated. In particular, we found that the majority of the strongest dB/dt events (100–1000nT/min) appear to be produced by the vortex-type current structures and most of them occur in the morning LT hours, probably caused by the Ps6 pulsation events associated with auroral omega structures. For strong dB/dt events the solar wind parameters are shifted toward strong (tens nT) southward IMF, enhanced velocity and dynamic pressure, in order for the main phase of the magnetic storms to occur. Although these events appear mostly during magnetic storms when the auroral oval greatly expands, the area of large dB/dt stays in the middle part of the auroral zone; therefore, it is connected to the processes taking part in the middle of the magnetosphere rather than in its innermost region populated by the ring current. Key words. Geomagnetism and paleomagnetism (rapid time variations) – Ionosphere (auroral ionosphere; ionospheric disturbances)

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

Annales Geophysicae ◽

10.5194/angeo-34-427-2016 ◽

2016 ◽

Vol 34 (4) ◽

pp. 427-436 ◽

Cited By ~ 2

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.

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