Characterizing poqer systems for seismic response or risk analysis

ABSTRACT

Power systems are complex networks that have a high degree of redundancy incorporated into their designs to improve system reliability. The redundancy includes multiple circuits that use diverse routes on the transmission and sub-transmission systems between nodes, and also incorporates redundancy into the design of systerm nodes, that is, its substations. A method is presented for modeling power systems to assess their response that takes into account both levels of redundancy. The methodology accommodates different levels of detail to describe the network to meet different application needs. The methodology can be used to estimate direct losses and the extent and duration of disruption from scenario earthquakes. To determine the duration of disruption, the restoration process must be characterized and must include realistic methods used by utilities to restore service under emergency conditions. The focus of the paper is on formulating generic substation models based on data used by utilities for load flow analysis combined with limited description of design practices provided by utilities. The importance of including local soil effects on substation perfomance in fragility estimates is dicussed.(AU)