Estimation of the geomagnetically induced current magnitude in the Central power district of the Kamchatka power system

A simulation of the geoelectric field, voltages on power transmission lines and geomagnetic induced currents (GIC) in the power lines of the Central Power District of the Kamchatka Region power system during an extreme magnetic storm was performed. The calculation uses a one-dimensional model of the lithosphere electrical conductivity distribution at Kamchatka with an average electrical resistivity of about 100 Ohms$\cdot$m. The length and orientation of power lines, the linear resistance of their wires, the resistance and number of transformers at terminal substations, as well as the GIC distribution effect between neighboring closely located substations in the agglomeration «Petropavlovsk-Kamachsky — Elizovo» are taken into account. It is shown that the GIC amplitude can reach 1 A at the power lines «Mutnovskaya geothermal power plant — electrical substation Avacha» and «Elizovo — Milkovo» which are oriented along the meridian. On a 110 kV power line «Apacha — Yelizovo», which is oriented in the latitudinal direction, a GIC value of about 1.5 A can be observed. An assessment of the GIС effect on power transformers at the Apacha electrical substation showed that the intensity of the magnetic field generated by GIC in the transformer core does not exceed 24 % of the intensity of the working magnetic field. Such an effect is not dangerous for the transformer, but it can cause the generation of even harmonics.