Node-breaker topology representation of Con Edison's Stations for planning studies

This paper describes a methodology and an automated process to implement node-breaker capabilities for representing major stations within Con Edison's footprint. This process creates a “hybrid” power flow model of Con Edison's system such that the user-defined stations are represented using the node-breaker model and the rest of the system is modeled using bus-branch representation. The process is implemented within the Physical and Operational Margins (POM) Suite software, which automatically expands the existing planning load flow case to incorporate nodebreaker modeling of the stations, and automatically generate breaker-oriented contingency lists. For those stations, which are represented using the node-breaker model, a breakeroriented contingency list is automatically generated. For the rest of the system, a contingency list consists of transmission line, transformer and generator outages. The breaker -oriented contingency list and the list of single element outages are automatically combined into one master contingency list. The “hybrid” model allows Con Edison to more accurately model contingencies for NERC-compliance studies.