An expert system for secondary distribution system design

The authors present the development and use of SECOND, a rule-based expert system (ES) for radial, electric power secondary distribution system design accommodating a projected load growth over a specified time horizon. SECOND is implemented in an integrated environment involving Prolog, conventional languages, and a graphic user interface (GUI) toolkit. SECOND makes use of conventional languages (Fortran/C) for algorithm-based numerical calculations, since Prolog is inefficient for this purpose. It also incorporates a window-based user interface (implemented in C) using the GUI toolkit: SunView. The window handling functions are performed by a set of predicates collected into a Prolog library. The data and information on secondary distribution system components are encoded in state frames (SFs), which organize numerical and nonnumerical data into defined slots. This information is then used by the rule-based procedures to arrive at an acceptable design