Analysis of Seismic Resilience and Repair Economics of Complex Network Systems in Substations

The design of substation systems is characterized by its complexity and high level of integration, as it encompasses various types of electrical equipment housed within a confined building structure, interconnected through meticulously arranged wiring. This paper presents a methodology for evaluating the seismic resilience of substation systems, which integrates a directed graph model of power pathways with Simulink electrical simulations. The substation is conceptualized as a power transmission pathway formed by interconnected equipment and wiring, leading to the establishment of a directed graph model that represents the substation system network. An evaluation of seismic resilience is conducted from the perspective of a high-voltage multi-input to low-voltage multi-output system, yielding median values and logarithmic standard deviations of seismic capacity across different functional requirements. The failure probabilities associated with the ten outgoing lines of the substation are analyzed through nonlinear fitting, while Monte Carlo simulation is employed to assess the vulnerability of the substation system. By utilizing the actual electrical capacity of the substation system as a reference point, the overall functional state of the substation is characterized, and resilience indicators pertinent to seismic conditions in substations are proposed. Utilizing the strength-based assessment methodology outlined in FEMAP-58, a systematic evaluation of the maintenance costs for substations was conducted under three distinct seismic intensity conditions. This analysis delineated the probability distribution of maintenance costs across various numerical ranges and illustrated the probability distribution of the median maintenance cost (i.e., the P=50% quantile) within these ranges.