- Conventional automation and control devices are passive and responsive. These devices typically respond to changes in the power system as measured against fixed thresholds and preset limits. These systems are designed to prevent catastrophic failures and incorrect operations and work well for general data acquisition and remote supervisory control. However, feedback control, system diagnostics, advanced protection, and contingency control are difficult to implement on the ever changing power system with these conventional approaches. Knowledge based systems have the potential for following the changes in the power system and adjusting decision criteria accordingly. Decisions can be made on a more complete data base which is constantly adjusted to changes ir system parameters and operation. This paper describes the various functions where knowledge based systems could ideally be used. The use of a knowledge based, adaptive system approach for diagnosing distribution system disturbances and equipment failures is presented. Two field experiments are described. Copyright 1987 by The Institute of Electrical and Electronics Engineers, Inc.