Feature Extraction For Geomagnetic Field Variations Aimed At Geomagnetically Induced Current In Power Grid

When geomagnetic storms caused by solar activity occurs, geomagnetically induced current in power grid will threaten safe operation of power systems, thus it is important to research on GIC in power grid. The main research content is as follows:In this paper, based on geomagnetic storm data measured by several mid-to-low latitude geomagnetic observatories, the variation law of the amplitude of north-south and east-west geomagnetic component change rate pulse with geomagnetic latitude is analyzed when geomagnetic field changed very severely, the possibilities of power grid in different direction beening affected by GIC with the change of latitude are discussed. The analysis results will contribute to the evaluation of GIC in Chinese current and future power grid. Based on the plane wave algorithm, the "converter" of calculating surface electric fieldin real time with geomagnetic measurement signal is set up. It can be used for real-time monitoring GIC in power grid with "conveter" and thus estimating the storm’s impact on grid, which can not use the rate of change of the magnetic field directly. According to the output of signal "converter", a selection criteria of the geomagnetic field pulse that may produce a significant GIC in grid are established and spectrum of data selected is analyzed. The selection and analysis results will lay the foundation for more accurately calculating the electric field.