Reliability assessment of multiple substations in Idaho system using a node-breaker model

The reliability performance of transmission substations and switching stations is critical to the overall system reliability. The outage of an element in a substation can result in multiple outages of other network elements, such as lines and transformers, and can lead to cascading events. Traditionally, probabilistic techniques have been applied to a bus-branch (BB) model, and to assess the impact of substation-related outages, it was necessary to manually add substation configurations. This paper presents an approach for assessing the reliability of multiple substations in Idaho Power Company (IPC) system using a detailed node-breaker (NB) model representation. The paper also presents an approach to automatically generate a large number of contingencies from the NB model that can be used in complying with the North American Electric Reliability Corporation (NERC) Transmission System Planning Performance Requirements (TPL) and performing system reliability studies. The presented approach is illustrated using a portion of the actual IPC system that includes all 230 kV and higher voltage substations.