MILP-based framework for seismic resilience evaluation and enhancement of substations

Abstract

In order to minimize earthquake impacts, substation rehabilitation requires an optimal sequence for defining repair priorities. In this paper, a continuous rehabilitation process is discretized to reduce the nonlinearity of the seismic resilience evaluation. Thus, a newly proposed post-earthquake rehabilitation strategy based on mixed integer linear programming (MILP) can be applied to find the optimal rehabilitation sequence. In particular, this strategy can evaluate the global optimality of the obtained rehabilitation sequence. A differentiated retrofitting strategy for substation equipment based on iterated local search (ILS) is also proposed to improve the seismic robustness. Case study shows that the MILP rehabilitation strategy can find out the globally optimal rehabilitation sequences in most simulated scenarios, which obviously increases the restorative capacity. Meanwhile, the proposed retrofitting strategy improves the seismic robustness more significantly than other strategies. Thus, the seismic resilience of the substation was enhanced comprehensively by the proposed method.