WP1: Power Grid Model
Compile a DC description of the European high-voltage power network and update existing GIC modelling software. Compile (for validation and comparison) two regional models (UK and NW Russia).
Other contributors: FMI, BGS, PGI
- Technical note on the European power grid model:
D1.1 DC description of power grids
Ari Viljanen, Risto Pirjola and Magnus Wik
A model of the European high-voltage power grids is a basic input to the tasks of the EURISGIC project (European Risk from Geomagnetically Induced Currents). Due to the quasi-dc nature of geomagnetically induced currents (GIC), only a DC description is needed. This contains a list of transformer stations (nodes), their locations and resistances, and a list of transmission lines and their resistances. Because GIC is divided uniformly between three phases, a single-phase reduction can be done. This means that resulting GIC are expressed as the sums of the currents in the three phases.
The purpose of the EURISGIC grid model is to provide a prototype which covers whole Europe and has a realistic number of nodes and lines, so that it gives a reasonable understanding of the occurrence of GIC in dierent parts of the continent. The model must also be easy to extend and adjust whenever additional information becomes available.
The European power grid system consists of four parts, which are connected by DC lines. From the GIC viewpoint, these parts can be considered separately. The largest part is the South and Central Europe, and the other parts are the Baltic countries, Nordic countries and British Isles. The number of nodes of the whole model used here is 1487 (1107 in South and Central Europe) and there are 2027 transmission lines (1557 in South and Central Europe). The voltage levels included are 400 kV, 330 kV and 220 kV. This fixed conguration will be the basic input in the later EURISGIC studies.
This document starts with a general overview of the GIC modelling method applied within EURISGIC. Then the construction of the power grid model is described and approximations are explained. Eects on GIC due to varying power grid parameters are discussed by simple examples with comparisons to GIC in the prototype grid model. We have applied the old widely-used Finnish grid model of 1978-79 as a reference, and veried that the basic GIC modelling works reliably with much larger grids too. Applications of the prototype model with real geophysical input data are described in an accompanying document by Viljanen et al. (2012).
- Technical note on GIC software:
D1.2 GIC software
Ari Viljanen, Risto Pirjola and Magnus Wik
Developing the main products of the EURISGIC project (European Risk from Geomagnetically Induced Currents) require powerful computation of geomagnetically induced currents (GIC) in a continent-wide power grid of more than 1000 nodes and transmission lines. Previous GIC studies have dealt with national grids in fairly small geographic areas. Within EURISGIC, the previous scientic models and software developed at the Finnish Meteorological Institute (FMI) since 1980's has served as the starting point.
The main modules of the new software are:
1) General settings: earth conductivity models, power grid model, denition of input magnetic field data.
2) Calculation of the ionospheric equivalent current system from measured geomagnetic variations.
3) Interpolation of the magnetic field to the nodes of the power grid by utilising equivalent currents.
4) Calculation of the geoelectric field at the nodes using the local plane wave method.
5) Calculation of GIC due to the geoelectric field.
All modules were already included in the older software at FMI, but major improvements in computational performance have been made by vectorising the code, and also by making it compatible both with MatLab and Octave. Calculation of the geovoltages between nodes is now made in the spherical geometry whereas the old code assumed a planar geometry. Comparison between these methods shows a good correspondence and generally only small differences between them.
Performance tests were made with Octave (in MacBook Pro and FMI Linux server) and MatLab (in FMI Linux server). Calculation of 1-minute values of GIC at 1107 nodes of the South and Central Europe prototype power grid model takes about 30 minutes per year. Consequently, the new code is fast enough for extensive runs to derive GIC statistics in later phases of EURISGIC.
- Technical note on regional studies (UK):
D1.3 UK Regional GIC Studies
Ciaran Beggan and Alan W P Thomson
This report is the published product of a study by the British Geological Survey (BGS) as part of the EURISGIC project (NEE4272SF and NEE3710F) into geomagnetically induced currents in the high voltage UK power system. We report on model developments since 2010, including a re-evaluation of the October 2003 impact on the UK grid system and an analysis of the impact of hypothetical extreme space weather events on the grid.
- Technical note on regional studies (RU):
D1.4 GIC recording and local model of N-W Russian power grid
Yaroslav Sakharov, Yurij Katkalov and Ari Viljanen
One task of the EURISGIC project (European Risk from Geomagnetically Induced Currents) is investigation of space weather impacts on main power lines in North-West Russia. For this purpose a special system was constructed for GIC recordings, data storage and use for GIC modeling. This document describes the data acquisition system, GIC recording unit and power grid model used within EURISGIC.
- Public online tool: