An expert system for fault diagnosis integrated in existing SCADA systems

The operators of Hydro-Quebec´s 9 Regional Control Centres (RCC) are sometimes overloaded by the number of alarm messages produced when automatic controls operate to clear faults. To help operators, Hydro-Quebec has developed an expert system to perform a continuous analysis of alarm messages, automatically detect the application of the protection or restoration control and then produce a concise, real-time diagnosis identifying the origin and consequences of the fault. This paper describes the fault diagnosis problem faced by operators and the requirements met by the LANGAGE Expert System. It gives an overview of the knowledge representation technique used and of the actual distribution of the application that allows the execution of the various modules of LANGAGE in many computers and workstations installed in parallel with the existing SCADA system