Development of an expert system for power system protection coordination

The author describes the development of a prototype expert system for the protection coordination of an industrial power system. The system has proved successful to-date, however the knowledge base requires expansion to cover a larger portion of the application domain. Therefore, the reliability and integrity of the system are still to be tested. The graphic user interface can respond within nearly a second, even for redrawing a large power system map. On the other hand a computation and reasoning time is rather long. The protection coordination computation takes about 10 seconds for the previous example but each reasoning of answer takes about one minute to get a solution. The use of empirical rules results in a faster computation when heuristic search techniques can be used to integrate analytical techniques into an expert system