New Electric Shipboard Topologies for High Resiliency

Abstract

All-electric ships commissioned for military use must survive any physical attack resulting in short-circuit faults that lead to service interruption. Unlike previous works on improving resiliency, this paper seeks to design new topologies by understanding the relationship between the resiliency and the structural topology of a shipboard power system (SPS). Resiliency is evaluated on the basis of the total load served in a network following an attack, which causes maximum disruption in the network. The worst-case attack is identified using a bilevel and a mixed-integer linear programming framework. This method is employed to analyze the resiliency of similarly sized nominal SPS topologies (in terms of load and generator ratings). Breaker-and-a-half and ring bus topologies are determined to be more resilient, as they can survive up to $\text{eight}$ simultaneous worst-case attacks. Based on the study of structural dependence of resiliency, two new topologies are designed that can survive up to $\text{14}$ worst-case attacks each. It is to be noted that the new topologies are designed with the same number of circuit breakers, DC buses, and lines as the nominal topologies.