The Effects of Geomagnetic Storms on Electrical Power Systems

Geomagnetic field fluctuations produce spurious, quasi-dc currents in power systems. The currents enter through system grounding points, and are of sufficient magnitude to cause half-cycle saturation in power transformers. These currents have been recorded and are summarized, and recommendations made in the significant problem areas of system disturbances and equipment effects due to geomagnetic storms. The major problem areas include increased VAR requirements and shifts in VAR flow, system-voltage fluctuations, generation of harmonics, protective relayiing misoperations, and possible localized internal heating in transformers. Recommendations relating to these effects have Pot been published previously.