Estimating geomagnetically induced currents at sub-auroral and low latitudes to assess their effects on power systems

During large magnetic storm the geomagnetically induced current has a negative impact on ground conducting technology systems. The time derivative of the horizontal component of the geomagnetic field (dH/dt) is greater than 30nT/min for induced currents causing undesirable consequence in power grids. Multiple regression analyses were developed to predict the level of geomagnetic disturbance using time derivatives of the horizontal geomagnetic field, east and north components of the geoelectric field, auroral electrojet and disturbance storm times from 1994-2007 at low and subauroral latitudes. The statistical test RMSE (Root Mean Square Error) and MBE (Mean Bias Error) were employed to evaluate the accuracy of the geomagnetic disturbance. Different variables have been used to develop different types of models. Values of the correlation coefficient and the coefficient of determination were high, which indicates that the results are good. The equations produced the best correlations at subauroral and low latitudes, and the best correlation was obtained with low values of RMSE and MBE.