Simulation Calculation of Influence of DC Bias Suppression of Grounding Electrodes on GIC of Hami Power Grid

Abstract

A lot of HVDC projects in China adopted capacitor blocking devices to suppression DC bias magnetic. This method will lead to a redistribution of the DC bias current and the geomagnetic induced current of the power grid, increasing the risk of geomagnetic storm hazards to the power grid. For the Tianshan grounding Electrode DC bias magnetic suppression of the Tianzhong HVDC project, the GIC model for 750 kV and 220 kV Hami grid was established. The GIC of grid before and after suppression was calculated using 1V/km geoelectric field and MATLAB programming. The impact of capacitor blocking devices on the GIC of 750 kV and 220 kV Hami grid was compared. The results show that the use of capacitor blocking devices to suppress the DC bias current of the grounding electrode will increase the GIC of some transformers of neighboring substations in the power grid, and the research methods and results are of great significance to the GIC suppression of power grid.