Special Aspects of Neutral Grounding System of Power Transformers with Photothyristors During Space Weather Disturbances

Identified the protective system of power transformer of electric power system from the influence of geomagnetically induced currents during space weather disturbances. The main element of the system that has been suggested is a high voltage semiconductor key. The protective system consist a minimum quantity of semiconductor elements and fulfilled by the most simple power scheme which is implemented on the photo-thyristor base. Protective system of power transformer which was suggested allow fully block or limit to a low level intensity of geomagnetically induced currents.