The impact of GIC on system voltage and generator output

Aiming at the phenomenon of the system voltage decrease in the case of geomagnetic storms, a Geomagnetically Induced Current (GIC)-Direct Current (DC) bias simulation model with 2 generators and 5 buses based on the PSCAD/EMTDC platform is established, in which the GIC is simulated by low frequency sinusoidal alternating current, to analyze the mechanism of DC bias caused by GIC impacting the system voltage in this paper. Based on the simulation model, the variations of transformer reactive power consumption and system voltage are recorded. In addition, the impact of GIC on the generator output is studied. The results indicate that the consumption of transformer reactive power increases periodically with the increasing of GIC, which results in the periodic reduction of system voltage and decrease of generator output.