DIRECTIONAL SENSITIVITY TO GEOMAGNETICALLY INDUCED CURRENTS OF THE HYDRO-QUEBEC 735-KV POWER-SYSTEM

To examine the sensitivity to geomagnetically induced currents (GIC) o f the Hydro-Quebec 735 kV power system, model calculations were made o f the GIC produced by uniform electric fields directed northwards (azi muth of 0-degree) and with azimuths increasing in 15-degrees increment s. The results show that the maximum GIC was produced in the system fo r an electric field bearing 15-degrees. In addition the model results allow the variation of GIC amplitude with electric field direction to be examined for individual substations. Maximum GIC occurred at substa tions at the ends of a long transmission line when the electric field was aligned with the transmission line.