Enhancing Power System Resilience Under Geomagnetic Disturbances: Hazard Characterization, Vulnerability Assessment, and Mitigation Solutions

Abstract

The power grid's availability is vital for well-being, and economic functioning. However, its complexity and interconnections expose it to hazards such as severe weather and deliberate attacks. Geomagnetic disturbances (GMDs) caused by solar activities pose a significant threat, leading to reactive power losses, voltage instability, and transformer overheating due to geomagnetically induced currents (GICs). To prevent widespread system failure, it is crucial to identify and protect critical components. This dissertation assesses power systems during GMDs by modeling hazard, evaluating transformer thermal assessment, and proposing effective mitigation strategies. It employs a holistic approach, constructing GMD scenarios in large-scale power grids and utilizing advanced algorithms for GIC analysis. The research enhances our understanding of GMD analysis and its impact on power systems. This dissertation, in part, highlights the significance of correct modeling of generator step-up (GSU) transformers in GMD analysis. It sheds light on the potential risks that arise when the status of these critical transformers is disregarded during GMD analysis. By identifying at-risk transformers and analyzing their thermal response to GICs, this study proposes mitigation strategies that prioritize transformers based on failure hazard rates. This approach enhances the resilience of the grid during GMD events and enables utilities and system operators to better prepare for such occurrences. The proposed strategies mitigate potential risks and costs associated with transformer failure, ultimately strengthening the overall preparedness and response capabilities of power grids in the face of GMDs.