Patent ID: 7489485

Claim:
A method for protection of power transformers and other power system components, which are vulnerable to geomagnetically induced currents, which comprises feeding a DC-diverter from at least one of an overhead line or a cable conductor connected to the power transformers, said DC-diverter consisting of primary diverter windings and compensation windings applied on a respective magnetic core leg, which at least one DC-diverter is connected to critical busses, and diverting “quasi” direct current flowing on the at least one of an overhead line or a cable conductor as a result of earth surface potential gradients caused by geomagnetically induced currents, wherein said DC-inverter comprises a magnetic core structure having three phase legs, each leg provided with a primary diverter winding and each provided with a diverter compensation winding having a filter connected to the neutral point of the three-phase diverter to reduce harmonics, to eliminate flow of these through the compensation winding, and whereby the diverter has an impedance lower than that of a component diverted from.