Singular value decomposition in geomagnetically induced current validation

Geomagnetically induced currents (GICs) can cause transformer half cycle saturation and consequently affect the power grid with harmonic currents and increased reactive power loss. This paper focuses on using transformer neutral GIC measurements to help validate the GIC models. A linear GIC model is presented that relates the geoelectric field input to the transformer neutral GICs. To validate this model, a temporal GIC matrix model is introduced and the singular value decomposition (SVD) is used for estimating the geoelectric field. The effectiveness of the approach is shown using a 20 bus test case. Finally, the GIC model is extended to account for nonuniform electric field and its accuracy is evaluated through SVD.