Operation of electromechanical and microprocessor devices of relay protection during geoinduced current effect on electrical network in the period of magnetic storm

This paper presents investigation of operation of typical domestic electromechanical and microprocessor devices of relay protection at the geoinduced current (GIC) effect in the period of a magnetic storm. An experiment- calculated technology of the simulation of the relay protection devices operation in the electrical network was used. A 330 kV Olenegorsk-Monchegorsk signal in the current protection of the residual current realized on the basis of an electromechanical relay was the initial GIC data. The signal was recorded during the magnetic storm in the overhead power transmission line on November 24, 2001. It was shown that as opposed to an electromechanical relay, the GIC effect on the modern microprocessor device does not result in the actuation of its protection, as well as of the current protection of the residual current. The reason is the blocking of the GIC flow through the secondary measuring transformers of the device.