GEOSCAN Search Results: Fastlink


TitleDistributed-source transmission line theory for modeling the coast effect on geoelectric fields
AuthorWang, X; Boteler, D HORCID logo; Pirjola, R JORCID logo
SourceIEEE Transactions on Power Delivery (Institute of Electrical and Electronics Engineers) 2023 p. 1-10,
Alt SeriesNatural Resources Canada, Contribution Series 20210437
PublisherInstitute of Electrical and Electronics Engineers
Mediapaper; on-line; digital
File formatpdf
SubjectsScience and Technology; general geology; geomagnetic fields
Illustrationsdiagrams; tables; photographs
ProgramCanadian Hazard Information Service Geomagnetism and space weather
Released2023 05 24
AbstractGeomagnetic effects on man-made ground-based systems are an increasing concern such as power grids, submarine cables, pipelines, and railway systems. Assessing the threat to these systems requires calculating the geoelectric field induced at the Earth's surface during geomagnetic disturbances and using this as input to a system model to determine the electric currents flowing across the system. Calculations of the geoelectric fields need to take account of lateral variations in conductivity that can affect the geoelectric field at and near discontinuities such as the coast. This paper presents a new method for modeling the influence of coast effect on geoelectric fields based on a generalized thin sheet model but develops a solution derived from distributed-source transmission line theory. Transmission line segments are converted to equivalent-pi circuits which are held together to compose a nodal admittance network representing the Earth's surface and underlying crust. Inversion of the admittance matrix combined with magnetic source fields then determine the geoelectric field profile across the coast. Two cases are presented to show how the DSTL theory is applied to different Earth conductivity models. Calculation results are compared with numerical solutions obtained from FEM, which confirms the accuracy of the DSTL theory for computing geoelectric fields.
Summary(Plain Language Summary, not published)
Space weather refers to the dynamic conditions on the Sun and in the space environment, in particular, in the near-Earth environment, that can affect critical infrastructure. NRCan operates the Canadian Space Weather Forecast Centre and conducts research into space weather effects on power systems, pipelines, radio communications and GNSS positioning to help Canadian industry understand and mitigate the effects of space weather. This paper describes a new simpler method for calculating the coast effect on the geoelectric fields produced during geomagnetic disturbances. For this method an analogy is made between the Earth surface structure and an electrical transmission line. Transmission line theory is then used to derive a new set of equations that can be solved to show how the geoelectric field changes near the coast. This is valuable as a tool to incorporate into modelling geomagnetically induced currents in power systems and will provide more accurate assessments of geomagnetic effects on power systems.

Date modified: