Real-Time Contingency Analysis with RAS Modeling at CAISO

A significant challenge in situational awareness when operating the power grid is identifying concerns that require operator actions from those that are protected by Remedial Action Schemes (RAS) or Special Protection Schemes (SPS). Based on planning studies, utilities have set up RAS/SPS to mitigate expected issues in the Bulk Electric System. By incorporating RAS actions into Real Time Contingency Analysis (RTCA), California ISO (CAISO) is able to model and modify contingency definitions automatically and identify potential concerns accurately. RTCA allows operators to monitor thermal, voltage and bus angle violations for the loss of generation/transmission elements. By including RAS actions into the contingency analysis, operators can also know if the RAS actions are sufficient to mitigate any potential issues or if further actions are required. This paper discusses the use of enhanced RTCA with RAS modeling at CAISO and the lessons learned.