Measurement and analysis of neutral point currents in a 400-kV-network

Halbedl, Thomas Stefan; Renner, Herwig; Sakulin, Manfred; Achleitner, Georg

doi:10.1109/pq.2014.6866785

Cited by 13 publications

(18 citation statements)

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“…Research into GICs in Austria began in 2014 in a study initiated by the Austrian Power Grid AG (APG) and summarized in Halbedl et al. (2014). The aim of this first attempt was to investigate possible DC currents in the Austrian high voltage power transmission network.…”

Section: Introductionmentioning

confidence: 99%

Analysis of Long‐Term GIC Measurements in Transformers in Austria

et al. 2022

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Geomagnetically induced currents (GICs), a result of solar wind interaction with the Earth's magnetic field and the resistive ground, are known to flow in power transmission grids, where they can lead to transformer damage and grid operation problems. In this study we present an analysis of five years of continuous GIC measurements in transformer neutral points in Austria. Seven self‐designed stand‐alone measurement systems are currently installed in the Austrian 220 and 380 kV transmission levels, measuring currents up to 25 A. We identify recurrent geomagnetic activity in the measurements, and also find man‐made sources of low frequency currents using frequency analysis. In order to support the transmission grid operators, two GIC simulation approaches are used to simulate GICs in the power grid. The first model uses measurements to derive the sensitivity of the location to northward and eastward geoelectric field components (which requires no detailed grid data), and the second model uses the detailed grid model to compute GICs from a geoelectric field. We evaluate two geomagnetic storms from September 2017 and May 2021 to discuss the effects of GICs on the power transmission grid and its assets.

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Section: Introductionmentioning

confidence: 99%

Analysis of Long‐Term GIC Measurements in Transformers in Austria

et al. 2022

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“…Previous studies in Austria have established basic models of GICs in the Austrian power network managed by the Austrian Power Grid (APG) and analyzed the first sets of measurements (Bailey et al, ; Halbedl et al, , ). Measurements of direct currents flowing through the neutral points of transformers have been carried out across the network by the APG and Technical University of Graz, starting in 2014 with one specific node and adding four more stations in 2016 and 2017.…”

Section: Introductionmentioning

confidence: 99%

Validating GIC Models With Measurements in Austria: Evaluation of Accuracy and Sensitivity to Input Parameters

et al. 2018

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Space weather events can cause geomagnetically induced currents (GICs) in power transmission networks. Over the past years, these currents have been measured in multiple substations in Austria, and the measurements have been tested against a model of local GIC with the aim of producing an optimized model, which can be developed through evaluation of various input parameters. We show the impact the choice of the local resistivity, in particular the surface conductivity in thin-sheet modeling, and the source of geomagnetic variations has on GIC modeling. In addition, the sensitivity of the model to the accuracy of the network configuration is also investigated. This encompasses the inclusion of power grids outside of Austria in the model as well as the consequences of removal of a substation either through transformer failure or active disconnection. Results show that a detailed surface conductivity model brings benefits to areas with large lateral conductivity variations and that there are certain substations that lead to increases and decreases of GIC in the rest of the network when removed. The importance of regionally representative geomagnetic field measurements is also highlighted and shown to impact model accuracy. This study concentrates on regional effects, but the results are also valid for large-scale studies elsewhere. node and adding four more stations in 2016 and 2017. The purpose of this paper is to expand on the former study using the same model and particularly to utilize measurements collected at multiple different stations to evaluate the importance and required accuracy of model input parameters for the best results.

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“…The higher levels of noise were eventually correlated with geomagnetic activity. Soon after, in partnership with the APG, studies into the presence and nature of GICs in Austria were started (Halbedl et al, 2014(Halbedl et al, , 2016.…”

Section: Introductionmentioning

confidence: 99%

Modelling geomagnetically induced currents in midlatitude Central Europe using a thin-sheet approach

et al. 2017

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Abstract. Geomagnetically induced currents (GICs) in power systems, which can lead to transformer damage over the short and the long term, are a result of space weather events and geomagnetic variations. For a long time, only high-latitude areas were considered to be at risk from these currents, but recent studies show that considerable GICs also appear in midlatitude and equatorial countries. In this paper, we present initial results from a GIC model using a thinsheet approach with detailed surface and subsurface conductivity models to compute the induced geoelectric field. The results are compared to measurements of direct currents in a transformer neutral and show very good agreement for shortperiod variations such as geomagnetic storms. Long-period signals such as quiet-day diurnal variations are not represented accurately, and we examine the cause of this misfit. The modelling of GICs from regionally varying geoelectric fields is discussed and shown to be an important factor contributing to overall model accuracy. We demonstrate that the Austrian power grid is susceptible to large GICs in the range of tens of amperes, particularly from strong geomagnetic variations in the east-west direction.

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Measurement and analysis of neutral point currents in a 400-kV-network

Cited by 13 publications

References 0 publications

Analysis of Long‐Term GIC Measurements in Transformers in Austria

Analysis of Long‐Term GIC Measurements in Transformers in Austria

Validating GIC Models With Measurements in Austria: Evaluation of Accuracy and Sensitivity to Input Parameters

Modelling geomagnetically induced currents in midlatitude Central Europe using a thin-sheet approach

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