Session 15 - Ground-based Operational and Infrastructure Impacts of Space Weather

Ellen Clarke (BGS), Gemma Richardson (BGS)
Friday 01/12, 9:45 - 13:00
Permeke


KEYWORDS - Ground-effects, Geomagnetically Induced Currents (GIC), electrical power networks, pipelines, railway signalling, geophysical prospecting, measurement-while- drilling (MWD)

The effects of Space Weather on the ground, such as unwanted geomagnetically induced currents in power systems and railway signalling systems, pipe-to-soil potentials in pipelines, increased error in, or cancellations of, aeromagnetic surveys and reduced drilling accuracy of measurement while drilling tools are all reasonably well known and documented. This does not mean to say, however, that the measurement, modelling, prediction and mitigation of these ground effects have been successfully resolved to the satisfaction of all industries affected. This session seeks contributions from engineers and researchers alike that focus on any aspect of space weather ground effects, including monitoring, modelling, prediction and mitigation. Presentations that advance our understanding of the impacts on operations and infrastructures and those where key, unresolved problems are identified will be especially welcome.

Poster Viewing
From Thursday morning to Friday noon

Talks
Friday December 1, 09:45 - 11:00, Permeke
Friday December 1, 11:45 - 13:00, Permeke

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Talks : Time schedule

Friday December 1, 09:45 - 11:00, Permeke

09:45	Space Weather Research Program focused on the Energy Sector in the UK	Ruffenach, A et al.	Invited Oral
	Alexis Ruffenach
	EDF Energy R&D UK Centre ltd, United Kingdom
	Extreme space weather events such as major geomagnetic storms could have a serious impact on ground level infrastructure. In the UK, since 2011, this hazard has been included inside the National Risk Register (a governmental document listing the significant potential risks to the UK). EDF Energy is the largest producer of low carbon electricity in the UK and the safety of its assets is the overriding priority. Our R&D group have been investigating and characterizing the potential impacts related to very intense space weather events such as geomagnetic storms (GIC) and neutron irradiation at ground level from GLE. In this talk, we shall give an overview of our R&D work and ongoing academic collaborations.
10:15	Modelling electric fields in Ireland and UK for space weather applications	Campanya, J et al.	Oral
	Joan Campanyà[1], Peter Gallagher[1], Seán Blake[1], Mark Gibbs[2], David Jackson[2], Ciarán Beggan[3], Gemma S. Richardson[3], Colin Hogg[4]
	[1]School of Physics, Trinity College Dublin, Dublin, Ireland; [2]Met Office, Exeter, UK; [3]British Geological Survey, Edinburgh, UK; [4]Dublin Institute for Advanced Studies (DIAS), Dublin, Ireland
	Solar storms can significantly disturb the Earth's magnetic field, producing induced electric fields (IEF) at the Earth’s surface. The IEF are the primary input for the estimation of geomagnetically induced currents (GICs), which can cause interruptions in electrical power distribution networks and have the potential to cause large economic losses. We tested several approaches for modelling the IEF recorded at the HAD, ESK, and LER magnetic observatories by using magnetic time series from INTERMAGNET observatories (HAD, LER, ESK, and VAL), and from the Irish magnetic observatory network (MagIE). The tested approaches contemplate: • The role of the subsurface geology at defining the IEF. We used magnetotelluric (MT) geophysical data to constrain the influence of the subsurface geology, including the use of inter-station transfer functions which relate the electric fields at specific location to the magnetic fields at the magnetic observatories. • The influence of ionospheric currents. The ionospheric currents were modelled following two different approaches to correct the non-valid assumption of plane-wave approximation during strong geomagnetic storms: 1) Using spherical elementary current system (SECS), and 2) assuming that the aurora electro-jet can be represented by a line of current. We also implemented methods based on machine learning techniques for modelling IEF from the magnetic time series as an alternative approach not based on physical properties. Differences between measured and predicted IEF in the time and frequency domain were quantified using the correlation coefficient, the performance parameter, and root-mean-square error. We evaluated the capacities and limitations of the methods and defined a suitable approach for modelling IEF in Ireland and UK.
10:30	Planning new improvements for modelling and measuring geomagnetically induced currents in Spain	Torta, J et al.	Oral
	J. Miquel Torta[1], Alex Marcuello[2], Joan Campanyà[3], Santiago Marsal[1], Pilar Queralt[2], Juanjo Ledo[2]
	[1]Observatori de l’Ebre, CSIC-URL, Roquetes, Spain; [2]Institut Geomodels, Universitat de Barcelona, Spain; [3]School of Physics, Trinity College Dublin, Ireland
	Vulnerability assessments of the risk posed by geomagnetically induced currents (GICs) to power transmission grids benefit from accurate knowledge of the geomagnetic field variations at each node of the grid, the Earth’s geoelectrical structures beneath them, and the topology and relative resistances of the grid elements in the precise instant of a storm. The results of previous analyses on the threat posed by GICs to the Spanish 400 kV grid have been improved by resorting to different strategies to progress in the three aspects identified above. Firstly, although at mid-latitude regions the source fields are rather uniform, we have investigated the effect of their spatial changes by interpolating the field from the records of several closest observatories with different techniques. Secondly, we have performed a magnetotelluric (MT) sounding in the vicinity of one of the transformers where GICs are measured to determine the geoelectrical structure of the earth, and we have identified the importance of estimating the MT impedance tensor when predicting GIC, specially where the effect of lateral heterogeneities is important. Finally, a sensitivity analysis to network changes has allowed us to assess the reliability of both the information about the network topology and resistances, and the assumptions made when all the details or the network status are not available. In our case, the most essential issue to improve the coincidence between model predictions and actual observations came from the use of realistic geoelectric information involving local MT measurements. Lessons learnt from this and our previous GIC assessments are used to design a new plan for establishing a series of local MT surveys to properly map the non-homogeneous geoelectric field, enabling the matching between the model predictions and actual GIC measurements across the entire Spanish territory. The number of GIC measurements are also planned to be increased by indirectly obtaining them with the deployment of magnetometers under some selected power lines, in contrast with the more usual way of measuring the current in the neutrals of the transformers at substations, and thus avoiding the necessity of interfering with the power companies.
10:45	Simulations of GICs in the Fully Resolved Irish Power Network over 25 Years	Anon, A et al.	Oral
	Sean Blake[1,2], Peter T. Gallagher[1], Joe McCauley[1], Joan Campanya[1], Alan G. Jones[3], Colin Hogg[2], Ciaran D. Beggan[4], Alan W.P Thomson[4], Gemma S. Richardson[4], David Bell[5]
	[1]School of Physics, Trinity College Dublin, Ireland; [2]Dublin Institute for Advanced Studies, Dublin; [3]Complete MT Solutions, Manotick, Ontario, Canada; [4]British Geological Survey, Lyell Centre, Riccarton, UK; [5]Eirgrid Plc, Ballsbridge, Ireland
	Geomagnetically induced currents (GICs) are a well-known space weather hazard, known to arise both in high latitude countries and mid-latitude countries such as Ireland. Modelling power networks for geomagnetic storms often require a number of assumptions be taken. These include simplifying the characteristics of individual substations as well as the galvanic connections between power networks in different countries. Lower voltage networks are often omitted from simulations for simplicity, introducing uncertainty into GIC calculations. Ireland's relatively small network presents an opportunity to model a stand-alone network with as few assumptions as possible. To this end, a complete model of the Irish 400, 275, 220 and 110 kV network was made for GIC calculations, including individual detailed characteristics of individual substations. We took into account the number, type and winding resistances of individual transformers in substations, and in some cases measured substation grounding resistances. This network model was subjected to a number of sensitivity tests which include quantifying the influence of each of the variables have on calculated GICs (for example, grounding resistances and ground switches for transformers). Using spherical elementary currents and a magnetotelluric approach to calculate surface electric fields, GICs were calculated from 25 years of near-continuous geomagnetic data (1991-2015). Here we present the statistical results of these simulations.

Friday December 1, 11:45 - 13:00, Permeke

11:45	Recent advances and validation of GIC modelling in the UK	Richardson, G et al.	Oral
	Gemma Richardson, Ciaran Beggan, Alan Thomson
	British Geological Survey
	We present a major upgrade to the power network model for the mainland UK and provide a validation of it with respect to both measured and synthetic data. Although we have only limited measured geomagnetically induced current (GIC) data with which to verify fully this updated model, we present an investigation of the sensitivity or accuracy of the model at each step in the modelling process: (1) The input geomagnetic field – we investigate the variability in modelled substation GIC with respect to network distance from magnetic field measurements made at magnetic observatories. (2) The electric field calculation - we use electric field measurements at the three UK observatories to test both the code and conductivity model used to compute the electric field across the UK. (3) The estimation of GICs in the power network - we use the test network provided by Horton et al. (2012), to test our modelling methodology and to validate the code at the GIC calculation step using a uniform electric field. (4) As a final step, we compare the output from the complete modelling chain with a small set of GIC measurements available for the March 2015 storm. We find that magnetic field measurements from observatories within a few hundred kilometres of the network can be used to estimate GIC within 30-40% of the true value; whilst observatories that are further away are less reliable, underestimating the largest values and recording false extremes. We also find good agreement between modelled and measured electric fields and GIC, giving us confidence that our models are providing sensible estimates of GIC. This research has benefitted from support from Natural Environment Research Council grant number NE/P017231/1.
12:00	Long term Geomagnetically Induced Current Observations in New Zealand: Earth return Corrections and Geomagnetic Field Driver	Clilverd, M et al.	Oral
	Daniel Mac Manus[1], Craig Rodger[1],Michael Dalzell[2],Alan Thomson[3],Mark Clilverd[4],Tanja Petersen[5],Moritz Wolf[6],Neil Thomson[1]
	[1]Department of Physics, University of Otago, Dunedin, New Zealand; [2]Transpower New Zealand Limited, New Zealand; [3]British Geological Survey (NERC), United Kingdom; [4]British Antarctic Survey (NERC), Cambridge, United Kingdom; [5]GNS Science, New Zealand; [6]Department of Applied Sciences and Mechatronics, Munich University of Applied Sciences, Munich, Germany
	Transpower New Zealand Limited has measured DC currents in transformer neutrals in the New Zealand electrical network at multiple South Island locations. Near continuous archived DC current data exist since 2001, starting with 12 different substations, and expanding to include 17 substations. From 2001-2015 up to 58 individual transformers were simultaneously monitored. Primarily the measurements were intended to monitor the impact of the High Voltage DC system linking the North and South Islands when it is operating in "Earth return" mode. However, after correcting for Earth return operation, the New Zealand measurements provide an unusually long and spatially detailed set of Geomagnetically Induced Current (GIC) measurements. Here we describe the New Zealand DC observations, and the corrections required to identify GIC in this dataset. We also examine the peak GIC magnitudes observed during two large geomagnetic storms, which occurred on 6 November 2001 and 2 October 2013. Both events were initiated by interplanetary shocks which hit when New Zealand was on the dayside of the Earth. In a transformer located at Islington near Christchurch, peak currents of ~20 A were observed during both events, although the temporal behaviour differed. Peak currents of ~30-50A were seen across South Island, depending on the measurement location. Our results show that for these two events there is a strong correlation between the magnitude of the GIC and the rate of change of the horizontal magnetic field (H').
12:15	GIC modelling in Austria: comparison to long-term measurements in multiple stations	Bailey, R et al.	Oral
	Rachel Bailey[1], Thomas Halbedl[2], Ingrid Schattauer[3], Alexander Römer[3], Georg Achleitner[4], Ciaran Beggan[5], Ramon Egli[1], Roman Leonhardt[1]
	[1]Zentralanstalt für Meteorologie und Geodynamik; [2]TU Graz; [3]Geological Survey of Austria; [4]Austrian Power Grid; [5]British Geological Survey
	Measurements of geomagnetically induced currents (GIC) in Austria have been conducted since 2014, and in recent years simultaneous measurements from three different power grid substations across Austria have become available. A model of GIC in Austria has been developed based on measurements of geomagnetic variations, the conductivity structure in Austria and the nature of the network. This model has undergone many iterations in the form of a detailed parameter study, with each set of results compared to GIC measurements from multiple stations across Austria to determine which parameters lead to an improvement in model accuracy. Here we present the results of this study and conclusions on which input parameters are most important for accurate GIC modelling.
12:30	Modelling and Mitigation of Geomagnetically Induced Currents in New Zealand: Working down to the Transformer-Level	Rodger, C et al.	Oral
	Craig J. Rodger[1], Tim Divett[1], Michael Dalzell[2], Ciaran Beggan[3], Gemma Richardson[3], Daniel H. Mac Manus[1], Alan W P Thomson[3], and Mark A. Clilverd[4]
	[1]Department of Physics, University of Otago, Dunedin, New Zealand; [2]Transpower New Zealand Limited, Wellington, New Zealand; [3]British Geological Survey, Edinburgh, United Kingdom; [4]British Antarctic Survey (NERC), Cambridge, United Kingdom
	Transpower New Zealand Limited has measured DC currents in transformers in the New Zealand electrical network at multiple South Island locations. The measurements provide an unusually long and spatially detailed set of Geomagnetically Induced Current (GIC) measurements. GIC are a clear hazard to the New Zealand electrical network, with the loss of a $2 million transformer in November 2001 during a very large magnetic storm. Near continuous archived DC current data exist since 2001, starting with 12 different substations, expanding over time to presently include 17 substations. From 2001-2015 up to 58 individual transformers were simultaneously monitored. We have begun a research project to analyse the New Zealand GIC dataset in order to better understand the occurrence and impact of GIC to the New Zealand electrical network. We are working with Transpower New Zealand Limited to examine their existing GIC mitigation plans and recommend modifications. Initial results from that effort will be discussed. In order to advance our understanding of these impacts, and the potential severity of GIC on this network during extreme events, we have developed a network model of the South Island’s electrical transmission network. It is driven by modelled geoelectric fields to calculate expected GIC. New Zealand’s geomagnetic latitude and island nature are similar to the United Kingdom and Ireland, allowing us to build on previous modelling approaches developed there. However, previous GIC models assume that each substation can be represented by a single resistor in series with an earth-ground resistor. By contrast, in the present study we have developed a more detailed transformer-level network model, although still using the same nodal network structure as in previous studies. In this model we represent every high and low voltage winding of each individual transformer as a unique resistor, based on DC electrical properties provided by Transpower. The need for this transformer-level detail is demonstrated by the observation that GIC in transformers in the same substation can be more than an order of magnitude different due to their differing designs. The model confirms that the magnitude of high GIC "hot spots" identified at the substation level may be very different to the equivalent "hot spots" when the transformer-level is considered.
12:45	An assessment of the spatial scales of second-minute scale dB/dt magnetic disturbances driving GICs: What spatial density of ground magnetometer stations is needed for GIC monitoring?	Dimitrakoudis, S et al.	Oral
	Stavros Dimitrakoudis, David K. Milling, Ian R. Mann, Andy Kale, Ivan Pakhotin
	University of Alberta
	A major ground effect of space weather is the driving of geomagnetically induced currents (GICs) in terrestrial electrical power grids, arising from induced electric fields from magnetic field changes in the coupled magnetosphere-ionosphere-ground system. Since ground dB/dt can be used as a GIC proxy, arrays of ground magnetometers can be used to study the temporal and spatial structure and evolution of large magnetic disturbances driving GICs. Most previous studies have used 10 second to 1 minute data to examine dB/dt associated with GICs. Here we use higher temporal resolution 1 to 2 second data to study the response to two magnetic storms using data from two magnetometer arrays, a very dense network of 75 stations deployed temporarily from June to July 1998 in the Baltic Electromagnetic Array Research (BEAR) Project in Scandinavia and the Canadian Array for Realtime Investigations of Magnetic Activity (CARISMA; www.carisma.ca) array in North America. These arrays have the benefit of allowing the characterisation of the longitudinal extent, and the high spatial resolution structure, of large amplitude dB/dt from second to minute timescales. In particular, we examine the magnitude and coherence of the dB/dt in such timescales and examine the optimal spacing between magnetometers, in latitude and longitude, which might be required for monitoring and determining GIC risk as a function of the timescale of the disturbance.

Posters

1	Strengths and weaknesses of monitoring useful realtime mid-latitude geomagnetic disturbances: Local Disturbance index and Local Current index	Guerrero, A et al.	e-Poster
	Antonio Guerrero, Elena Saiz, Consuelo Cid, Judith Palacios, Yolanda Cerrato
	Space Weather Group, Departamento de Física y Matemáticas, Universidad de Alcalá, Alcalá de Henares, Spain
	Space weather users are still relying in low resolution and/or global character geomagnetic indices which do not fit their needs. Moreover, at mid-latitude location the geomagnetic disturbances capable to disrupt technology come with different appearances and some of them are not being monitored. The Local Disturbance index and the Local Current index for Spain (LDiñ and LCiñ) developed by the Space Weather group at University of Alcala offer a real-time monitoring of hazardous disturbances without missing strong local disturbances like field-aligned currents. The high value of these products is achieved thanks to its realtime operation to effectively remove solar regular variations for mid-latitudes. We will show the improvement respect to other geomagnetic indices and in the case of LCiñ its correlation with GICs measured at the systems of the Spanish power company.
2	Association between space weather conditions and emergency ambulance calls for elevated arterial blood pressure	Vencloviene, J et al.	p-Poster
	Jone Vencloviene[1], Deivydas Kiznys[1], Agne Braziene[1], Paulius Dobozinskas[2]
	[1]Vytautas Magnus University, Lithuania; [2]Lithuanian University of Health Sciences, Lithuania
	Researchers who analyzed the effect of increased geomagnetic activity on human health have detected a biological response 2-3 days before the onset of geomagnetic disturbances. The aim of the study was to detect the complex association between daily emergency ambulance calls (EAC) for elevated arterial blood pressure (EABP) and space weather conditions, adjusting for the impact of the month of the year, the day of the week, day length, and weather variables. The multivariate Poisson regression was used, and the risk areas for a higher EAC were detected by applying the classification and regression tree technique. During the period of the study (January 1, 2009 – June 30, 2011), 17,114 cards of EAC at Kaunas city ambulance service were used. A significant increase in the daily number of EAC for EABP was detected on the second day after the Ap≥16 period and on the 2nd day before the Ap≥16 onset. To detect the changes in solar wind parameters that were associated with an increase in daily EAC before days of Ap≥16, we analyzed mean values of solar wind parameters on 6 days preceding the onset of Ap≥16. During the sixth – the second days before the onset of Ap≥16, a significantly (p=0.023) increased trend in the daily Stream Interaction Regions rate was observed. A significant increase (p=0.016) in solar wind dynamic pressure (P) was observed on the 4nd day before Ap≥16 as compared to two previous days. In addition, during the fourth – the second days before the onset of Ap≥16, a decrease in the mean values of solar wind density (Np), P, and plasma beta was observed. The second day before Ap≥16 was associated with significantly lower Np and P, as compared to the 4nd day before Ap≥16. An increase in the risk of EAC was associated with an increase in mean daily plasma beta by 2.5 times (Rate ratio (RR) =1.09, p=0.002), days of CME-HALO with solar wind dynamic pressure >1.815 nT two days before (RR=1.14, p=0.017), the fall in daily P as compared to that observed two days before (P at lag 2 days >1.78 nT and P<1.02 nT) (RR=1.14, p<0.001), and high-speed solar wind (RR=1.14, p=0.002). Daily variations in solar wind dynamic pressure and plasma beta may be used as new risk factors for human health.
3	Characterizing the geomagnetic field variability for the study of magnetic storm impact on electric power lines	Belakhovsky, V et al.	p-Poster
	Pilipenko V.A.[1], Belakhovsky V.B.[1], Sakharov Ya.A.[2], Selivanov V.N.[3]
	[1]Institute of Physics of the Earth, Moscow, Russia; [2]Polar Geophysical Institute, Apatity, Russia; [3]Kola Scientific Center, Apatity Russia
	Geomagnetically induced currents (GIC) are often modeled as fluctuations of intensity of the east-west auroral electrojet. On the basis of these notions, it is commonly supposed that geomagnetic disturbances are most dangerous for technological systems extended in longitudinal direction. Here we apply new characteristics do describe variability of the geomagnetic field during two moderate magnetic storms. These characteristics calculated from the data of IMAGE magnetometer array are compared with results of GIC recording at Kola Peninsula and in Karelia. This system for recording of GIC in the power lines that has been deployed and operated since 2010. This system consists from 5 stations elongated in latitudinal direction. The GIC intensity is determined by variations of geomagnetic field. We apply to the geomagnetic data various techniques to characterize the geomagnetic field variability: vector mapping of time series and a measure of time variations of vector angle cosines. These techniques have shown that during moderate magnetic storms on March 17, 2013 and June 28-29, 2013 the ionospheric currents fluctuate not just in E-W direction, but chaotically in both E-W and N-S directions.
4	SWIGS: A New UK Research Consortium to Study ‘Space Weather Impacts on Ground-based Systems’	Thomson, A et al.	p-Poster
	Alan Thomson (on behalf of the SWIGS consortium*)
	British Geological Survey
	The British Geological Survey leads a new UK Natural Environment Research Council funded study into ‘Space Weather Impacts on Grounded Structures’ (SWIGS), through a four-year research project that started in May 2017. The SWIGS consortium of ten UK institutes and universities will research links between the magnetosphere and ionosphere, the generation of geo-electric fields, through interaction of geomagnetic variations with the solid Earth, and the impact of enhanced geomagnetic activity on ground infrastructures such as high voltage power grids, rail and pipeline networks. SWIGS is supported by an industry stakeholder group and a group of international project partners that includes advisors and experts from the Finnish Meteorological Institute, Natural Resources Canada, UK Met Office, North China Electric Power University, and the Universities of Cape Town, Otago, Trinity College Dublin, Frankfurt, Gottingen, John Hopkins and Beihang. In addition to research that improves physical models of the space weather interaction with Earth’s space environment and the space weather threat to ground level technologies, SWIGS will also promote workshops and other meetings. In this poster presentation, we outline some of the primary questions we want to answer within SWIGS and we detail the research goals of the project. * Dr Ciaran Beggan1, Dr Yulia Boganova6, Prof Jeremy Chittenden5, Dr Mark Clilverd3, Prof Malcolm Dunlop6, Dr Emma Eastoe4, Dr Jonathan Eastwood5, Dr Robert Fear7, Dr Mervyn Freeman3, Prof Mike Hapgood6, Dr Andrew Kavanagh3, Dr Phil Livermore8, Prof Mike Lockwood9, Dr Jon Mound8, Dr Matthew Owen9, Dr Jonathan Rae10, Dr Gemma Richardson1, Dr Fiona Simpson7, Prof Katherine Whaler2, Prof Jim Wild4 1. British Geological Survey, 2. University of Edinburgh, 3. British Antarctic Survey, 4. University of Lancaster, 5. Imperial College, 6. Rutherford Appleton Laboratory, 7. University of Southampton, 8. University of Leeds, 9. University of Reading, 10. University College London
5	An investigation into Geoelectric tides at three sites in the UK	Baillie, O et al.	p-Poster
	Orsi Baillie[1,2], Kathy Whaler[2], Ciaran Beggan[1]
	[1]British Geological Survey, United Kingdom; [2]University of Edinburgh, United Kingdom
	Electric fields are created by the motions of sea water through the geomagnetic field. Continuous geoelectric field monitoring began at the UK magnetic observatories in 2012/2013 alongside the standard geomagnetic field measurements. The three observatories are in quite different settings in relation to the seas surrounding the British Isles and the new data allow investigation of any tidally generated signals. More generally, the new electric field measurements will provide ground-truth data to test the accuracy of electric field estimates calculated using the geomagnetic field data and models of the electrical conductivity structure beneath the observatories for space weather studies. In this work, an investigation into the effects of periodic phenomena has been carried out, revealing both solar and lunar signals. Firstly, superposed epoch analysis has been performed. The results for Hartland observatory are consistent with the findings of previous experiments in the English Channel, with regard to the magnitude of solar and lunar semi-diurnal (S2 and M2) variations. Secondly, frequency analysis, using the fast Fourier transform has been used to find the dominant frequencies present in the electric field data again identifying known Sq-harmonics and the dominant motion-induced M2 tidal period at each station. There are difficulties in carrying out conventional Fourier analysis because of gaps in the data. This limits the length of continuous input data sets and so the frequency resolution. To overcome this problem, we have also used the Lomb-Scargle periodogram to investigate the spectrum as this method permits gaps in the data. We have also calculated the correlation between the geoelectric field components and data from closest tidal gauge stations to each site. As very accurate tidal models are available, confirmation of the expected periods provides the motivation to attempt to model and remove the predictable tidal component of the geoelectric field variations. If successful this will help isolate the space weather effects in the measurements.
6	Space weather effects and Polish energy infrastructure	Gil, A et al.	p-Poster
	A. Gil[1], R. Modzelewska[1], P. Szmitkowski[2], A. Wawrzynczak[3]
	[1]Siedlce University, Faculty of Sciences, Institute of Mathematics and Physics, 08-110 Siedlce, Poland; [2]Siedlce University, Faculty of Humanities, Social Science and Security Institute; [3]Siedlce University, Faculty of Sciences, Institute of Computer Sciences
	Geomagnetically induced currents (GIC) impact on electrical grids and energetic infrastructure as a whole is very well known. Fortunately, failures caused by GIC are not so enormous as Hydro-Quebec blackout on the 13th of March 1989. In the connection with Polish energetic infrastructure in the literature cannot be found many information. Thorberg (2012) reported that during the Halloween Storm, October/November 2003, there were two events on SwePol Link. SwePol it is the 600 MW, 450 kV high voltage direct current (HVDC) connection under the Baltic Sea, between Poland and Sweden. The owners are the PSE-Operator S.A., operator of the Polish national grids and the Swedish national grid operator, the Svenska Kraftnat. On the 29th of October 2003, at 07:46 SwePol Link at Karlshamn tripped disrupting an import from Poland of 300 MW. And again, on the 20th of November 2003, at 18:04 an import from Poland of 400 MW was interrupted. Here we present results of analysis of a series of not very extensive failures in Polish electrical grids which occurred in July-September 2017 and were not caused by the meteorological effects. The analysed events coincide with the occurrence of geomagnetic disturbances caused by solar effects, as recurring coronal holes (especially north, but also transequatorial) appearance. References: Thorberg R., Risk analysis of geomagnetically induced currents in power systems, Lund 2012