Toward More Accurate GIC Estimations in the Portuguese Power Network

New geomagnetically induced current (GIC) computations for mainland Portugal include the entire power network, with network parameters and topology provided by transmission grid operator all high voltage lines (150, 220, 400 kV). The first 3D conductivity model west region of Iberian Peninsula, based on 31 broadband magnetotelluric soundings, is used in calculations, revealing effect different crustal domains GIC distribution. Geomagnetic field variations are taken from Coimbra or San Fernando magnetic observatories, according to Nearest Neighbor method, together surface impedance values predicted new calculate electric a regular grid. global distribution GICs over characterized results derived eight most significant storms registered Iberia during solar cycle 24. Substations susceptible highest found near transition between granitic geotectonic unit Central Zone Lusitanian Basin. A prototype Hall sensor has been installed at substation active since end August 2021. In order validate our model, recent measurements compared simulations. computation prone uncertainties various sources, possibly contributing weights final error computed values. Here, we evaluate contribution earthing resistance nonuniqueness uncertainties.