In-Field RAS Testing
Southern California Edison
Power grids are increasingly stressed and are increasingly relying on Remedial Action Schemes (RAS), which are last-resort tripwire schemes that are a generalization of traditional protection schemes. RAS schemes involve 3 or more substations, and are calibrated when first fielded. The question is, will they still work 10 or more years later when they are needed to prevent a large blackout? Sensor values drift, and other things can change. We note that misconfiguration of protection schemes (including RAS) is the #1 cause of major blackouts, including the recent one in San Diego. The goals of this activity were to develop a middleware framework to test RAS schemes in the field; to extend the framework, Erkios, to have a more formal specification of the RAS scheme to analyze its temporal characteristics and eventually find bugs in existing RAS schemes; and to integrate actual relays into Erkios in a lab at Washington State University. We investigated how Erkios’s application-unaware testing mechanisms could be combined with ARMOR’s application-aware software fault tolerance, and what benefits might accrue to the development and testing of future RAS schemes with such a system. We also integrated Erkios into DETERLab to enable more control over timing and reliability of message delivery and node failures.