scholarly journals The Lehtinen-Pirjola Method Modified for Efficient Modelling of Geomagnetically Induced Currents in Multiple Voltage Levels of a Power Network

2021 ◽  
Author(s):  
Risto J. Pirjola ◽  
David H. Boteler ◽  
Loughlin Tuck ◽  
Santi Marsal
Keyword(s):  
Power Systems ◽  
Transmission Lines ◽  
Efficient Method ◽  
Positive Definite Matrix ◽  
Cholesky Decomposition ◽  
Multiple Time ◽  
Power Network ◽  
Geomagnetically Induced Currents ◽  
Admittance Matrix ◽  
Induced Currents

Abstract. The need for accurate assessment of the geomagnetic hazard to power systems is driving a requirement to model geomagnetically induced currents (GIC) in multiple voltage levels of a power network. The Lehtinen-Pirjola method for modelling GIC is widely used but was developed when the main aim was to model GIC in only the highest voltage level of a power network. Here we present a modification to the Lehtinen-Pirjola (LP) method designed to provide an efficient method for modelling GIC in multiple voltage levels. The LP method calculates the GIC flow to ground from each node. However, with a network involving multiple voltage levels many of the nodes are ungrounded, i.e. have infinite resistance to ground which is numerically inconvenient. The new modified Lehtinen-Pirjola (LPm) method replaces the earthing impedance matrix [Ze] with the corresponding earthing admittance matrix [Ye] in which the ungrounded nodes have zero admittance to ground. This is combined with the network admittance matrix [Yn] to give a combined matrix ([Yn]+[Ye]), which is a sparse symmetric positive definite matrix allowing efficient techniques, such as Cholesky decomposition, to be used to provide the nodal voltages. The nodal voltages are then used to calculate the GIC in the transformer windings and the transmission lines of the power network. The LPm method with Cholesky decomposition also provides an efficient method for calculating GIC at multiple time steps. Finally, the paper shows how software for the LP method can be easily converted to the LPm method and provides examples of calculations using the LPm method.

scholarly journals Comparison of methods for modelling geomagnetically induced currents

2014 ◽  
Vol 32 (9) ◽  
pp. 1177-1187 ◽  
Author(s):  
D. H. Boteler ◽  
R. J. Pirjola
Keyword(s):  
Power Systems ◽  
Transmission Lines ◽  
Matrix Method ◽  
Low Voltage ◽  
Geoelectric Field ◽  
Geomagnetically Induced Currents ◽  
Common Path ◽  
Admittance Matrix ◽  
Induced Currents ◽  
Matrix Expression

Abstract. Assessing the geomagnetic hazard to power systems requires reliable modelling of the geomagnetically induced currents (GIC) produced in the power network. This paper compares the Nodal Admittance Matrix method with the Lehtinen–Pirjola method and shows them to be mathematically equivalent. GIC calculation using the Nodal Admittance Matrix method involves three steps: (1) using the voltage sources in the lines representing the induced geoelectric field to calculate equivalent current sources and summing these to obtain the nodal current sources, (2) performing the inversion of the admittance matrix and multiplying by the nodal current sources to obtain the nodal voltages, (3) using the nodal voltages to determine the currents in the lines and in the ground connections. In the Lehtinen–Pirjola method, steps 2 and 3 of the Nodal Admittance Matrix calculation are combined into one matrix expression. This involves inversion of a more complicated matrix but yields the currents to ground directly from the nodal current sources. To calculate GIC in multiple voltage levels of a power system, it is necessary to model the connections between voltage levels, not just the transmission lines and ground connections considered in traditional GIC modelling. Where GIC flow to ground through both the high-voltage and low-voltage windings of a transformer, they share a common path through the substation grounding resistance. This has been modelled previously by including non-zero, off-diagonal elements in the earthing impedance matrix of the Lehtinen–Pirjola method. However, this situation is more easily handled in both the Nodal Admittance Matrix method and the Lehtinen–Pirjola method by introducing a node at the neutral point.

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 Geomagnetically induced currents in the Irish power network during geomagnetic storms

Space Weather ◽  
2016 ◽  
Vol 14 (12) ◽  
pp. 1136-1154 ◽  
Author(s):  
Seán P. Blake ◽  
Peter T. Gallagher ◽  
Joe McCauley ◽  
Alan G. Jones ◽  
Colin Hogg ◽  
...  
Keyword(s):  
Geomagnetic Storms ◽  
Power Network ◽  
Geomagnetically Induced Currents ◽  
Induced Currents

MAG-GIC: Geomagnetically Induced Currents risk hazard in the Portuguese power network

2020 ◽  
Author(s):  
Joana Alves Ribeiro ◽  
Maria Alexandra Pais ◽  
Fernando J. G. Pinheiro ◽  
Fernando A. Monteiro Santos ◽  
Pedro Soares
Keyword(s):  
Solar Cycle ◽  
Geomagnetic Storms ◽  
Power Network ◽  
The South ◽  
Geomagnetically Induced Currents ◽  
Crust And Upper Mantle ◽  
Solar Cycle 24 ◽  
Induced Currents ◽  
Cycle 24 ◽  
Shunt Reactors

<p>The MAG-GIC project has as a main goal to produce the chart of Geomagnetically Induced Currents (GIC) risk hazard in the distribution power network of Portugal mainland.</p><p>The study of GICs is important as they represent a threat for infrastructures such as power grids, pipelines, telecommunication cables, and railway systems. A deeper insight into GICs hazard may help in planning and designing more resilient transmission systems and help with criteria for equipment selection.</p><p>GICs are a result of variations in the ionospheric and magnetospheric electric currents, that cause changes in the Earth's magnetic field. The Coimbra magnetic observatory (COI) is one of the oldest observatories in operation in the world and the only one in Portugal mainland. It has been (almost) continuously monitoring the geomagnetic field variations since 1866, and in particular, it has registered the imprint of geomagnetic storms during solar cycle 24. Besides the geomagnetic storm signal, which represents the GICs driver, the crust and upper mantle electrical conductivities determine the amplitude and geometry of the induced electric fields.</p><p>To present a better approximation of the Earth's conductivity structure below the Portuguese power network, we initiated a campaign to acquire magnetotelluric (MT) data in a grid of 50x50 km all over the territory. Nonetheless, there already exist enough MT data to create a realistic 3D conductivity model in the south of Portugal.</p><p>The other important input is the electric circuit for the network grid. We benefit from the collaboration of the Portuguese high voltage power network (REN) company, in providing the grid parameters as resistances and transformer locations, thus allowing us to construct a more precise model. In particular, we implement in our model the effect of shield wires and shunt reactors resistances.</p><p>In this study, we present the results of GIC calculations for the south of Portugal for some of the strongest geomagnetic storms in the 20015-17 period recorded at COI during solar cycle 24. We will focus on the sensitivity of results concerning two different conductivity models and different values of the shielding circuit parameters and shunt reactors devices.</p>

scholarly journals Geomagnetically induced currents in the New Zealand power network

Space Weather ◽  
2012 ◽  
Vol 10 (8) ◽  
pp. n/a-n/a ◽  
Author(s):  
R. A. Marshall ◽  
M. Dalzell ◽  
C. L. Waters ◽  
P. Goldthorpe ◽  
E. A. Smith
Keyword(s):  
New Zealand ◽  
Power Network ◽  
Geomagnetically Induced Currents ◽  
Induced Currents

scholarly journals Mitigating the effects of geomagnetically induced currents in the power network

2020 ◽  
Vol 14 (23) ◽  
pp. 5514-5525
Author(s):  
Ali Hesami Naghshbandy ◽  
Arman Ghaderi Baayeh ◽  
Ayda Faraji
Keyword(s):  
Power Network ◽  
Geomagnetically Induced Currents ◽  
Induced Currents

scholarly journals Prediction of geomagnetically induced currents (GICs) flowing in Japanese power grid for Carrington-class magnetic storms

2021 ◽  
Vol 73 (1) ◽  
Author(s):  
Yusuke Ebihara ◽  
Shinichi Watari ◽  
Sandeep Kumar
Keyword(s):  
Transmission Lines ◽  
Power Grid ◽  
Magnetic Storms ◽  
Power Grids ◽  
Geomagnetically Induced Currents ◽  
Geomagnetic Disturbances ◽  
Low Latitude ◽  
Solar Eruptions ◽  
Induced Currents ◽  
Extra High Voltage

AbstractLarge-amplitude geomagnetically induced currents (GICs) are the natural consequences of the solar–terrestrial connection triggered by solar eruptions. The threat of severe damage of power grids due to the GICs is a major concern, in particular, at high latitudes, but is not well understood as for low-latitude power grids. The purpose of this study is to evaluate the lower limit of the GICs that could flow in the Japanese power grid against a Carrington-class severe magnetic storm. On the basis of the geomagnetic disturbances (GMDs) observed at Colaba, India, during the Carrington event in 1859, we calculated the geoelectric disturbances (GEDs) by a convolution theory, and calculated GICs flowing through transformers at 3 substations in the Japanese extra-high-voltage (500-kV) power grid by a linear combination of the GEDs. The estimated GEDs could reach ~ 2.5 V/km at Kakioka, and the GICs could reach, at least, 89 ± 30 A near the storm maximum. These values are several times larger than those estimated for the 13–14 March 1989 storm (in which power blackout occurred in Canada), and the 29–31 October 2003 storm (in which power blackout occurred in Sweden). The GICs estimated here are the lower limits, and there is a probability of stronger GICs at other substations. The method introduced here will be immediately applicable for benchmark evaluation of low-latitude GICs against the Carrington-class magnetic storms if one assumes electrical parameters, such as resistance of transmission lines, with sufficient accuracy.

On-line Adaptive and Intelligent Distance Relaying Scheme for Power Network

2015 ◽  
Vol 16 (5) ◽  
pp. 473-489
Author(s):  
Rahul Dubey ◽  
S. R. Samantaray ◽  
B. K. Panigrahi ◽  
G. V. Venkoparao
Keyword(s):  
Power Systems ◽  
Transmission Lines ◽  
Model Updating ◽  
Test System ◽  
Operating Conditions ◽  
Power Network ◽  
Parallel Transmission ◽  
On Line ◽  
Distance Relaying ◽  
Learning Machine

Abstract The paper presents an on-line sequential extreme learning machine (OS-ELM) based fast and accurate adaptive distance relaying scheme (ADRS) for transmission line protection. The proposed method develops an adaptive relay characteristics suitable to the changes in the physical conditions of the power systems. This can efficiently update the trained model on-line by partial training on the new data to reduce the model updating time whenever a new special case occurs. The effectiveness of the proposed method is validated on simulation platform for test system with two terminal parallel transmission lines with complex mutual coupling. The test results, considering wide variations in operating conditions of the faulted power network, indicate that the proposed adaptive relay setting provides significant improvement in the relay performance.

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