Prospects of Using Thyristors to Protect Power Transformers of Electric Power Systems Against Geomagnetically Induced Currents

The paper presents chronological data on geomagnetic storms (GMS) to have caused blackouts or failures of power equipment in the electric power systems (EPS) around the globe. It is noted that extremely strong GMS may result in a large-scale failure of power transformers, entailing a long-lasting power outage. It is shown that GMS is a real threat to the Russian EPS due to the considerable obsolescence of power-plant and substation equipment, or power transmission lines; lack of recommendations to improve the functional resistance to geomagnetic storms does not help. The research team has developed principles of protecting power transformers against geomagnetically induced currents (GIC) during GMS by means of power semiconductor devices. We herein estimate the basic parameters and the components of thyristor-based power transformer protection against GIC.