Preliminary consideration of voltage stability impacts of geomagnetically induced currents

This paper provides a preliminary consideration of the voltage stability aspects of geomagnetically induced currents (GICs). Since the underlying geomagnetic disturbances (GMDs) can have rise times of less than one minute, there is a need to consider their impact on power system short-term voltage stability. The paper shows that the assumed dynamic models for loads and network controls such as load tap changing transformers (LTCs) can significantly reduce the GICs needed to cause a voltage collapse. Therefore more detailed dynamic simulations are recommended for inclusion in GIC studies.