GICs from the End User Perspective

During geomagnetic disturbance (GMD) events, variations in the Earth's magnetic field induce low-frequency currents (relative to power system frequencies) in the power grid.These lowfrequency currents are referred to as geomagnetically-induced current or GIC.The impacts of GIC on the power grid can range from thermal damage to bulk power transformers to voltage collapse.On March 13, 1989, the Hydro Quebec system experienced a blackout resulting from a severe GMD event.