Integrating model-based and heuristic features in a real-time expert system

The Intelligent Alarm Processor, an alarm expert system integrated in a remote monitoring and control facility for a 22-kV network of more than 1350 substations, is described. With the Intelligent Alarm Processor, operators can locate network faults, analyze fault types, and detect malfunctions in the protection system. The system filters alarms based on their importance and independence, and suppresses repetitive alarms. Since the Intelligent Alarm Processor uses a model of the protection system, it can also validate its correct operation. To achieve these functions in a reasonable response time, the expert system has been designed with several hierarchic diagnosis levels that use heuristic rules as well as compiled qualitative models.>