Geomagnetically induced currents in the Irish power network during geomagnetic storms

Blake, Seán P.; Gallagher, Peter T.; McCauley, Joseph L.; Jones, Alan G.; Hogg, Colin; Campanyà, Joan; Beggan, Ciarán; Thomson, Alan; Kelly, Gemma; Bell, D.

doi:10.1002/2016sw001534

Cited by 56 publications

(77 citation statements)

References 38 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…For example, Figure shows that Benmore and Aviemore have NER installed, while Tekapo B and Ohau A do not. The large variability seen in Figure is consistent with recent modeling results for the Irish power grid [ Blake et al ., ], where a constant 1 V/km geoelectric field produced large variations in GIC current throughout the network due to network configuration and differing ground conductivity.…”

Section: Storm Of 6 November 2001: Network Responsementioning

confidence: 99%

Long‐term geomagnetically induced current observations in New Zealand: Earth return corrections and geomagnetic field driver

et al. 2017

Self Cite

View full text Add to dashboard Cite

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 from 2009 to include 17 substations. From 2001 to 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, as described here, the New Zealand measurements provide an unusually long and spatially detailed set of geomagnetically induced current (GIC) measurements. We examine the peak GIC magnitudes observed from these observations during two large geomagnetic storms on 6 November 2001 and 2 October 2013. Currents of ~30–50 A are observed, depending on the measurement location. There are large spatial variations in the GIC observations over comparatively small distances, which likely depend upon network layout and ground conductivity. We then go on to examine the GIC in transformers throughout the South Island during more than 151 h of geomagnetic storm conditions. We compare the GIC to the various magnitude and rate of change components of the magnetic field. Our results show that there is a strong correlation between the magnitude of the GIC and the rate of change of the horizontal magnetic field (H′). This correlation is particularly clear for transformers that show large GIC current during magnetic storms.

show abstract

Section: Storm Of 6 November 2001: Network Responsementioning

confidence: 99%

Long‐term geomagnetically induced current observations in New Zealand: Earth return corrections and geomagnetic field driver

et al. 2017

Self Cite

View full text Add to dashboard Cite

show abstract

“…Although one generally expects that at middle to low latitudes the magnitude of GICs is 1 order of magnitude lower than that at high latitudes [ Pulkkinen et al ., ], recently there has been a great wealth of studies on the vulnerability assessment at those middle to low latitude grids [e.g., Demiray et al ., ; Liu et al ., ; Torta et al ., ; Barbosa et al ., ; Zhang et al ., ; Blake et al ., ]. The increasing concern about GICs as an emergent natural hazard has been boosted by the evidence that power system disturbances can be associated with the occurrence of geomagnetic sudden commencements (SCs) at those lower latitudes [ Kappenman , ; Torta et al ., ; Fiori et al ., ; Carter et al ., ].…”

Section: Introductionmentioning

confidence: 99%

Improving the modeling of geomagnetically induced currents in Spain

et al. 2017

Self Cite

View full text Add to dashboard Cite

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 are improved in this study by resorting to different strategies to progress in the three aspects identified above. First, although at midlatitude 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 close observatories with different techniques. Second, 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, especially 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.

show abstract

“…These are then in turn used as input into a model of the electric transmission network to calculate the resulting GIC. This method has been used to study GIC in France (Kelly et al, ), Ireland (Blake et al, ), and the UK (McKay, ), as well as being recently applied in New Zealand (Divett et al, ). Although such modeling has the potential to allow investigation of mitigation strategies by testing the effect of modifications to the transmission network on GIC, it also has significant drawbacks.…”

Section: Introductionmentioning

confidence: 99%

Assessment of GIC Based On Transfer Function Analysis

et al. 2017

View full text Add to dashboard Cite

Transfer functions are calculated for periods between 2 and 1,000 min between geomagnetically induced currents (GIC) measured at three transformers in the South Island of New Zealand and variations in the horizontal components of the geomagnetic field measured at the Eyrewell Observatory near Christchurch. Using an inverse Fourier transform, the transfer functions allow the GIC expected in these transformers to be estimated for any variation of the inducing magnetic field. Comparison of the predicted GIC with measured GIC for individual geomagnetic storms shows remarkable agreement, although the lack of high‐frequency measurements of GIC and the need for interpolation of the measurements lead to a degree of underestimation of the peak GIC magnitude. An approximate correction for this is suggested. Calculation of the GIC for a magnetic storm in November 2001 that led to the failure of a transformer in Dunedin suggests that peak GIC were as large as about 80 A. Use of spectral scaling to estimate the likely GIC associated with a geomagnetic storm of the magnitude of the 1859 Carrington Event indicates that GIC of at least 10 times this magnitude may occur at some locations. Although the impact of changes to the transmission network on calculated transfer functions remains to be explored, it is suggested that the use of this technique may provide a useful check on estimates of GIC produced by other methods such as thin sheet modeling.

show abstract

Geomagnetically induced currents in the Irish power network during geomagnetic storms

Cited by 56 publications

References 38 publications

Long‐term geomagnetically induced current observations in New Zealand: Earth return corrections and geomagnetic field driver

Long‐term geomagnetically induced current observations in New Zealand: Earth return corrections and geomagnetic field driver

Improving the modeling of geomagnetically induced currents in Spain

Assessment of GIC Based On Transfer Function Analysis

Contact Info

Product

Resources

About