Peculiarities of Power Transit by Overhead Lines Under Conditions of Geomagnetic Disturbances

The authors obtained analytical expressions to determine total power complexes at the beginning and the end of the intersystem overhead line with the account of the power transformer magnetizing branches' parameters. The latter allow the authors to consider the intensity of geomagnetic disturbances' influence on the electrical power transmission mode. It was demonstrated that the increase in the geomagnetically induced current intensity causes the decrease of the transmitted active power limit and is capable of a complete disturbance of reactive power transit due to the multiple increase of power transformer magnetizing power as a result of a unilateral saturation of magnetic systems. A numerical example is provided to illustrate the transmission capacity decrease and stop of reactive power transit at quite intense geomagnetic disturbances.