Real-time detection of vulnerable power system areas to geomagnetic disturbance

Abstract

This study proposes an approach for the fast and accurate identification of the vulnerable areas of the power system to geomagnetic disturbance (GMD). The proposed method can be used for real-time situational awareness and preparedness in power system control rooms and proactive mitigation of the GMD threats. In addition, it can be employed as an off-line GMD vulnerability assessment tool for power system planning analysis. In this study, a generalised mathematical basis is presented to find the maximum geomagnetically induced current (GIC) flow in the multi-zone earth structure based on the orthogonal GIC components. Furthermore, a real-time frequency estimation method is developed based on wavelet transform to estimate the frequency of the geomagnetic waveform for the maximum GIC calculation. The proposed approach is applied to the Ontario 500 and 230 kV transmission systems to identify the vulnerable equipment. The results are also compared with the angle sweep results. The numerical results reveal that not only the proposed method is more accurate but also significantly faster than the angle sweep method. Such prominent features introduce the proposed approach as a preferable method for real-time applications and optimisation of power system operation during GMDs.