Method for assessing the functionality of substations subjected to earthquakes based on network power flow analysis

Scholars have proposed various methods to evaluate the functionality of substations during seismic events. The HAZUS platform defined functionality simply as the ratio of properly operating equipment to the total, neglecting the electrical function and connectivity of the equipment. Recently, a more sophisticated method determined a substation’s functionality based on its maximum output power. Nevertheless, all existing methods treated the substation as an isolated entity from the power grid. In reality, the fluctuations in power flow within the grid can significantly affect the post-earthquake functionality assessment of the substation. Consequently, the existing methods may yield considerable errors, especially when the grid sustains substantial changes in the power flow distribution within the grid after an earthquake. In this regard, this paper presents a new method that accounts for the impact of network power flow on the substation’s functionality. It elucidates the underlying mechanism by which extensive damage to the power grid affects network power flow, subsequently impacting the functionality of the substation. Then, the framework of the proposed method is outlined, and a case study is conducted to compare its performance with existing methodologies. The results underscore the importance of incorporating the effect of network power flow into functionality assessments.