Extreme natural hazards can significantly degrade the survivability of field automation terminals (FATs), thereby affecting post-disaster service restoration (SR) in distribution systems (DSs). However, existing SR studies commonly assume fully available FATs and may consequently overestimate SR performance. To address this issue, this paper proposes a survivability-aware multi-period SR strategy for soft open point (SOP)-based DSs. The cyber-physical survivability of FATs is explicitly modeled through limited switching operations of spring-operated remote-controlled switches and constrained communication availability after faults. A multi-period SR optimization model is then developed by explicitly incorporating FAT survivability into the restoration decision-making process, together with time-varying ZIP load characteristics and distributed energy resource outputs. A nonlinear transformation method is further employed to transform the original optimization problem into a tractable form for efficient solution. Case studies on a modified IEEE 33-node system demonstrate that considering FAT survivability provides a more realistic assessment of SR capability, avoids overestimation of SR performance, and supports more reliable post-disaster decision-making.
