Long-lasting geomagnetically induced currents and harmonic distortion observed in New Zealand during the 07-08 September 2017 Disturbed Period
Clilverd, Mark A. ORCID: https://orcid.org/0000-0002-7388-1529; Rodger, Craig J.; Brundell, James B.; Dalzell, Michael; Martin, Ian; Mac Manus, Daniel H.; Thomson, Neil R.; Petersen, Tanja; Obana, Yuki. 2018 Long-lasting geomagnetically induced currents and harmonic distortion observed in New Zealand during the 07-08 September 2017 Disturbed Period. Space Weather, 16 (6). 704-717. 10.1029/2018SW001822
Before downloading, please read NORA policies.Preview |
Text (Open Access)
This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited. Clilverd-2018-Long-lasting-geomagnetically-induce.pdf - Published Version Available under License Creative Commons Attribution 4.0. Download (1MB) | Preview |
Abstract/Summary
Several periods of Geomagnetically Induced Currents (GIC) were detected in the Halfway Bush substation in Dunedin, South Island, New Zealand, as a result of intense geomagnetic storm activity during 06 to 09 September 2017. Unprecedented data coverage from a unique combination of instrumentation is analyzed, i.e., measurements of GIC on the single phase bank transformer T4 located within the substation, nearby magnetic field perturbation measurements, very low frequency (VLF) wideband measurements detecting the presence of power system harmonics, and high‐voltage harmonic distortion measurements. Two solar wind shocks occurred within 25 hours, generating four distinct periods of GIC. Two of the GIC events were associated with the arrival of the shocks themselves. These generated large but short‐lived GIC effects that resulted in no observable harmonic generation. Nearby and more distant magnetometers showed good agreement in measuring these global‐scale magnetic field perturbations. However, two subsequent longer‐lasting GIC periods, up to 30 minutes in duration, generated harmonics detected by the VLF receiver systems, when GIC levels continuously exceeded 15 A in T4. Nearby and more distant magnetometers showed differences in their measurements of the magnetic field perturbations at these times, suggesting the influence of small‐scale ionospheric current structures close to Dunedin. VLF receiver systems picked up harmonics from the substation, up to the 30th harmonic, consistent with observed high‐voltage increases in even harmonic distortion, along with small decreases in odd harmonic distortion.
Item Type: | Publication - Article |
---|---|
Digital Object Identifier (DOI): | 10.1029/2018SW001822 |
ISSN: | 15427390 |
Additional Keywords: | geomagnetically induced currents, transformer saturation, geomagnetic storm, harmonics, harmonic distortion, VLF |
Date made live: | 29 May 2018 11:00 +0 (UTC) |
URI: | https://nora.nerc.ac.uk/id/eprint/520168 |
Actions (login required)
View Item |
Document Downloads
Downloads for past 30 days
Downloads per month over past year