Korea Electric Power Corporation (KEPCO) has developed an expert system for load transfer analysis in power distribution systems since 1988.

When faults occur in power lines due to stormy weather conditions, traffic accidents, etc, automatic breakers between some sections of the power line are installed for protection against overcurrent and the reduce outage areas. Once faults occur, the system dispatcher tries to find the place where faults occur and to minimize the outage areas during the fault restoration by isolating the faulted portion through load transfer from other neighbor feeders.

Load transfer is not only needed to energize areas not affected by the work in progress during the outage, but also needed to investigate the possibility of load transfer in advance through contingency analysis before faults occur.

For optimal load transfer the system dispatcher has to look over the system configuration, select the neighbor feeders by considering distribution system constraints such as main transformer capacity and decide the status (open, close) of breakers to be operated for load transfer. This decision-making process is very involved.

The expert system integrated by Korea Infornet Co., Ltd. is inplemented on workstations by Sun Microsystems using Korean OSF/Motif by Trigem Computer, Inc. and IF/Prolog. The system is now in field operation at KEPCO. (The IF/Prolog Newsbrief 96-01)