Influence of Geomagnetic Storms on Power System Static Voltage Security

The adverse effects of geomagnetic storms on power systems have been confirmed by numerous examples and observations. However, there remains a dearth of research on the quantitative assessment of the safety risks of a system under extreme geomagnetic storm conditions. Accordingly, in this study, we developed a risk assessment model for magnetic storm disasters based on the static voltage security region theory from the global perspective of power grid security. First, we determined the boundary shape of the static security region of a system under magnetic storm conditions and analyzed its influence on the voltage stability of the system from a regional perspective. Subsequently, a static safe-distance index was proposed to characterize the influence of a magnetic storm disaster on the system voltage. Considering the uncertainty in the injected power during a magnetic storm, we calculated the static voltage instability probability of the system. Through probability index analysis, a probabilistic safety assessment of the system under magnetic storm conditions was performed, and its overall static voltage safety level was measured. Finally, a simulation analysis based on the UIUC 150 node showed the proposed method to be reasonable and effective.