scholarly journals Spatial Scale of Geomagnetic Pc5/pi3 Pulsations as a Factor of Their Efficiency in Generation of Geomagnetically Induced Currents

2020 ◽  
Author(s):  
Nadezda V. Yagova ◽  
Vyacheslav Pilipenko ◽  
Yaroslav Sakharov ◽  
Vasily Selivanov
Keyword(s):  
Electric Power ◽  
Spatial Scale ◽  
Large Scale ◽  
Power Transmission ◽  
Spatial Scales ◽  
Power Line ◽  
Small Scale ◽  
Geomagnetically Induced Currents ◽  
Electric Power Line ◽  
Induced Currents

Abstract Geomagnetically induced currents (GICs) in a meridional power transmission line at the Kola Peninsula are analyzed during the intervals of Pc5/Pi3 (frequency range from 1.5 to 5 mHz) pulsation activity observed at the IMAGE magnetometer network. We have analyzed GIC in a transformer at the terminal station Vykhodnoj (68◦N, 33◦E) during the entire year of 2015, near the maximum of 24-th Solar cycle. To quantify the efficiency of GIC generation by a geomagnetic pulsation, a ratio between power spectral densities of GIC and magnetic field variations is introduced. Upon examination of the efficiency of geomagnetic pulsations in GIC generation, the emphasis is given to its dependence on frequency and spatial scale. To estimate pulsation spatial scales in latitudinal and longitudinal directions, the triangle of stations KEV-SOD-KIL has been used. Large-scale pulsations along the electric power line (with a high spectral coherence, low phase difference, and similar amplitudes) are found to be more effective in GIC generation than small-scale pulsations. The accuracy of GIC prediction also depends on the pulsation scale transversal to the electric power line.

scholarly journals Spatial scale of geomagnetic Pc5/Pi3 pulsations as a factor of their efficiency in generation of geomagnetically induced currents

2020 ◽  
Author(s):  
Nadezda V. Yagova ◽  
Vyacheslav Pilipenko ◽  
Yaroslav Sakharov ◽  
Vasily Selivanov
Keyword(s):  
Spatial Scale ◽  
Large Scale ◽  
Power Transmission ◽  
Spatial Scales ◽  
Small Scale ◽  
Geomagnetically Induced Currents ◽  
Power Spectral ◽  
Electric Power Line ◽  
Induced Currents ◽  
Magnetic Field Variations

Abstract Geomagnetically induced currents (GICs) in a meridional power transmission line on the Kola Peninsula are analyzed during the intervals of Pc5/Pi3 (frequency range from 1.5 to 5 mHz) pulsations recorded at the IMAGE magnetometer network. We have analyzed GIC in a transformer at the terminal station Vykhodnoj (68 N, 33 E) during the entire year of 2015, near the maximum of 24-th Solar cycle. To quantify the efficiency of GIC generation by geomagnetic pulsations, a ratio between power spectral densities of GIC and magnetic field variations is introduced. Upon examination of the geomagnetic pulsation efficiency in GIC generation, the emphasis is given to its dependence on frequency and spatial scale. To estimate pulsation spatial scales in latitudinal and longitudinal directions, the triangle of stations KEV-SOD-KIL has been used. Large-scale pulsations (with a high spectral coherence, low phase difference, and similar amplitudes at latitudinally separated stations) are found to be more effective in GIC generation than small-scale pulsations. The GIC response also depends on the pulsation scale across the electric power line.

scholarly journals Spatial scale of geomagnetic Pc5/Pi3 pulsations as a factor of their efficiency in generation of geomagnetically induced currents

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Nadezda V Yagova ◽  
Vyacheslav A Pilipenko ◽  
Yaroslav A Sakharov ◽  
Vasily N Selivanov
Keyword(s):  
Spatial Scale ◽  
Large Scale ◽  
Power Transmission ◽  
Spatial Scales ◽  
Small Scale ◽  
Geomagnetically Induced Currents ◽  
Power Spectral ◽  
Electric Power Line ◽  
Induced Currents ◽  
Magnetic Field Variations

AbstractGeomagnetically induced currents (GICs) in a quasi-meridional power transmission line on the Kola Peninsula are analyzed during the intervals of Pc5/Pi3 (frequency range from 1.5 to 5 mHz) pulsations recorded at the IMAGE magnetometer network. We have analyzed GIC in a transformer at the terminal station Vykhodnoy ($$68^{\circ }$$ 68 ∘  N, $$33^{\circ }$$ 33 ∘  E) during the entire year of 2015, near the maximum of the 24th Solar cycle. To quantify the efficiency of GIC generation by geomagnetic pulsations, a ratio between power spectral densities of GIC and magnetic field variations is introduced. Upon examination of the geomagnetic pulsation efficiency in GIC generation, the emphasis is given to its dependence on frequency and spatial scale. To estimate pulsation spatial scales in latitudinal and longitudinal directions, the triangle of stations KEV-SOD-KIL has been used. Large-scale pulsations (with a high spectral coherence, low phase difference, and similar amplitudes at latitudinally separated stations) are found to be more effective in GIC generation than small-scale pulsations. The GIC response also depends on the pulsation scale across the electric power line.

scholarly journals Impulsive disturbances of the geomagnetic field as a cause of induced currents of electric power lines

2019 ◽  
Vol 9 ◽  
pp. A18 ◽  
Author(s):  
Vladimir Belakhovsky ◽  
Vyacheslav Pilipenko ◽  
Mark Engebretson ◽  
Yaroslav Sakharov ◽  
Vasily Selivanov
Keyword(s):  
Electric Power ◽  
Transmission Lines ◽  
Geomagnetic Field ◽  
Energy Yield ◽  
Interplanetary Shocks ◽  
Geomagnetically Induced Currents ◽  
Ionospheric Currents ◽  
Geomagnetic Variations ◽  
Electric Power Line ◽  
Induced Currents

Geomagnetically induced currents (GICs) represent a significant challenge for society on a stable electricity supply. Space weather activates global electromagnetic and plasma processes in the near-Earth environment, however, the highest risk of GICs is related not directly to those processes with enormous energy yield, but too much weaker, but fast, processes. Here we consider several typical examples of such fast processes and their impact on power transmission lines in the Kola Peninsula and in Karelia: interplanetary shocks; traveling convection vortices; impulses embedded in substorms; and irregular Pi3 pulsations. Geomagnetic field variability is examined using data from the IMAGE (International Monitor for Auroral Geomagnetic Effects) magnetometer array. We have confirmed that during the considered impulsive events the ionospheric currents fluctuate in both the East-West and North-South directions, and they do induce GIC in latitudinally extended electric power line. It is important to reveal the fine structure of fast geomagnetic variations during storms and substorms not only for a practical point of view but also for a fundamental scientific view.

scholarly journals Observed small spatial scale and seasonal variability of the CO<sub>2</sub> system in the Southern Ocean

2014 ◽  
Vol 11 (1) ◽  
pp. 75-90 ◽  
Author(s):  
L. Resplandy ◽  
J. Boutin ◽  
L. Merlivat
Keyword(s):  
Southern Ocean ◽  
Spatial Scale ◽  
Large Scale ◽  
Carbon Budget ◽  
Spatial Scales ◽  
Mixed Layer Depth ◽  
Small Scale ◽  
Spatiotemporal Resolution ◽  
Small Spatial Scale ◽  
Data Set

Abstract. The considerable uncertainties in the carbon budget of the Southern Ocean are largely attributed to unresolved variability, in particular at a seasonal timescale and small spatial scale (~ 100 km). In this study, the variability of surface pCO2 and dissolved inorganic carbon (DIC) at seasonal and small spatial scales is examined using a data set of surface drifters including ~ 80 000 measurements at high spatiotemporal resolution. On spatial scales of 100 km, we find gradients ranging from 5 to 50 μatm for pCO2 and 2 to 30 μmol kg−1 for DIC, with highest values in energetic and frontal regions. This result is supported by a second estimate obtained with sea surface temperature (SST) satellite images and local DIC–SST relationships derived from drifter observations. We find that dynamical processes drive the variability of DIC at small spatial scale in most regions of the Southern Ocean and the cascade of large-scale gradients down to small spatial scales, leading to gradients up to 15 μmol kg−1 over 100 km. Although the role of biological activity is more localized, it enhances the variability up to 30 μmol kg−1 over 100 km. The seasonal cycle of surface DIC is reconstructed following Mahadevan et al. (2011), using an annual climatology of DIC and a monthly climatology of mixed layer depth. This method is evaluated using drifter observations and proves to be a reasonable first-order estimate of the seasonality in the Southern Ocean that could be used to validate model simulations. We find that small spatial-scale structures are a non-negligible source of variability for DIC, with amplitudes of about a third of the variations associated with the seasonality and up to 10 times the magnitude of large-scale gradients. The amplitude of small-scale variability reported here should be kept in mind when inferring temporal changes (seasonality, interannual variability, decadal trends) of the carbon budget from low-resolution observations and models.

On the flow of geomagnetically induced currents in an electric power transmission network

2010 ◽  
Vol 88 (5) ◽  
pp. 357-363 ◽  
Author(s):  
Risto J. Pirjola
Keyword(s):  
Electric Power ◽  
Power Transmission ◽  
Power Grid ◽  
Space Physics ◽  
Practical Significance ◽  
Test Model ◽  
Geomagnetically Induced Currents ◽  
Geophysical Research ◽  
Model Calculations ◽  
Induced Currents

Geomagnetically induced currents (GICs) in conductor networks are among the ground-level effects of space weather. GICs are a possible source of problems to the system. Today, electric power transmission grids are the most important concern regarding GICs, which may in the worst cases lead to blackouts in large areas and permanent damage to transformers. The evaluation of GIC risks and the design of possible countermeasures require estimation of expected GIC magnitudes in transformers. This can be achieved by model calculations supplemented by GIC recordings at some sites. Although in principle GICs can flow all over a large galvanically-connected power grid, which should thus be included as a whole in a GIC calculation, the network must usually be restricted somehow in practical computations of GICs. By using a power grid test model, this paper provides a systematic numerical investigation showing that GICs do not flow over very long distances in a power grid, which is a good result and justifies the neglect of the parts of the network that lie far away from the area of primary interest. Besides practical significance in electric power engineering, studies of GICs can be used for space physics and geophysical research as well. It is also important to understand the features of the flow pattern of GICs in a network.

One Type Damper Used for Preventing Galloping of the Electric Power Line

2011 ◽  
Vol 374-377 ◽  
pp. 2057-2060
Author(s):  
Li Min Sun ◽  
Jing Chao Zou
Keyword(s):  
Transmission Line ◽  
Electric Power ◽  
High Speed ◽  
Power Transmission ◽  
Power Line ◽  
Power Transmission Line ◽  
Patent License ◽  
Electric Power Line ◽  
New Type ◽  
Overhead Power Line

When the power transmission line is covered with ice and snow in the winter, the galloping of power line often happens. A new type of damper used for preventing galloping of the electric power transmission line has been put forward and received patent license of China. The damper like fan blades, which can rotate about the axes of the power line at 360°, is fixed on the overhead power line. It hangs on the line when there is no wind. The blade rotates at high speed in the plane vertical to wind when there is wind, which results in a gyroscope. The theorem of angular momentum of a gyroscope is used in the design of the damper. Model tests of this kind of damper have been carried out and the results show that it is successful in preventing galloping of the cable model.

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