See Also
While operation contingencies are defined using breaker actions, planning cases use simplified device contingency actions. For instance, the outage of a single transmission line is modeled in EMS systems as the set of the actual circuit breaker actions that physically de-energize the transmission line. On the planning side, the same contingency is modeled as a single contingency action related to the transmission device: OPEN LINE.
A feature of PowerWorld’s Integrated Topology Processing is the ability to convert operations-type, circuit breaker contingencies to their electrically equivalent device contingencies for single outage, multiple outages, or complex post-contingency topologies. While both the breaker contingencies and the device contingencies can be solved on the Full-Topology Model, breaker contingencies MUST be converted to device contingencies in order to solve them on the consolidated Planning Case.
Some complex breaker contingencies cannot be converted to electrically equivalent topologies by simply changing the energization status of devices. A subset of the breakers involved in those contingencies may need to be preserved in the case to entirely reproduce the electric topology.
The Breaker-to-Device Contingency Conversion is launched from the Contingency Analysis Dialog > Other button > Convert to Device Contingencies. This routine will convert all the contingencies in the list. The contingency analysis status box will indicate the progress of the contingency conversion process. The log will also provide messages during the conversion.
The new list of converted device contingencies will replace the original list of breaker contingencies previously displayed on the Contingency Analysis Dialog. The list of device contingencies can be solved directly on the Full-Topology Model. On average, device contingencies include less device actions per contingency compared to breaker actions. For instance, a single line outage usually requires opening several circuit breakers, whereas the device contingency equivalent requires a single OPEN LINE contingency action.
In order to reflect the conversion process, the actions in the Contingency Definitions include device actions with the name of the device: Line, Transformer, Load, Gen, etc. and also Breaker if breakers need to be preserved for a given contingency.