Spectral characteristic of geomagnetically induced current during geomagnetic storms by wavelet techniques

AbstractWe need a typical method of directly measuring geomagnetically induced current (GIC) to compare data for estimating a potential risk of power grids caused by GIC. Here, we overview GIC measurement systems that have appeared in published papers, note necessary requirements, report on our equipment, and show several examples of our measurements in substations around Tokyo, Japan. Although they are located at middle latitudes, GICs associated with various geomagnetic disturbances are observed, such as storm sudden commencements (SSCs) or sudden impulses (SIs) caused by interplanetary shocks, geomagnetic storms including a storm caused by abrupt southward turning of strong interplanetary magnetic field (IMF) associated with a magnetic cloud, bay disturbances caused by high-latitude aurora activities, and geomagnetic variation caused by a solar flare called the solar flare effect (SFE). All these results suggest that GIC at middle latitudes is sensitive to the magnetospheric current (the magnetopause current, the ring current, and the field-aligned current) and also the ionospheric current.

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Long-Term Geomagnetically Induced Current Observations From New Zealand: Peak Current Estimates for Extreme Geomagnetic Storms

Space Weather ◽

10.1002/2017sw001691 ◽

2017 ◽

Vol 15 (11) ◽

pp. 1447-1460 ◽

Cited By ~ 16

Author(s):

Craig J. Rodger ◽

Daniel H. Mac Manus ◽

Michael Dalzell ◽

Alan W. P. Thomson ◽

Ellen Clarke ◽

...

Keyword(s):

New Zealand ◽

Geomagnetic Storms ◽

Induced Current ◽

Geomagnetically Induced Current ◽

Peak Current

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Study on Variation Rate Characters of Mid-to-Low Latitude Area Geomagnetic Field during Geomagnetic Storms

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.448-453.2125 ◽

2013 ◽

Vol 448-453 ◽

pp. 2125-2131

Author(s):

Xiao Mao Wang

Keyword(s):

Geomagnetic Field ◽

Geomagnetic Storms ◽

Power Grid ◽

Geomagnetic Latitude ◽

Induced Current ◽

Low Latitude ◽

Geomagnetically Induced Current ◽

Faraday’S Law ◽

Variation Rate ◽

Measurement And Control

Geomagnetic field changes acutely during geomagnetic storms. According to Faraday's law of electromagnetic induction, the change of the geomagnetic field produces geomagnetically induced current (GIC) in power grid, which directly damages the power equipment and threatens safe operation of power grid. The more dramatically geomagnetic field changes, the bigger geomagnetically induced current in power grid becomes, and thus, the greater harm it brings to power grid. In this paper, based on the H and D components of recent geomagnetic storm data measured by several mid-to-low latitude geomagnetic observatories, the variation law of the amplitude of north-south and east-west geomagnetic component change rate (dX/dt and dY/dt) pulse with geomagnetic latitude was analyzed when geomagnetic field changed very severely. Finally, the possibilities of power grid in different direction affected by GIC with the change of latitude were discussed. The analysis results will contribute to the evaluation, measurement and control of GIC in Chinese current and future power grid.

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