Fuzzy expert system for distribution system restoration and contingency operation

Over the years, computer technologies have been applied to operate the distribution system in the most reliable and efficient manner. In this work, a fuzzy expert system prototype had been developed to aid operators in distribution system restoration and contingency operation. The knowledge base, which contains the different strategies used in the project, had been adopted from the standard operating procedures of the Manila Electric Company (MERALCO). For restoration planning, the following factors were utilized in the evaluation of the solutions: percent load of the circuit and transformer and percent unbalance of the circuit. On the other hand, circuit overloads, transformer overloads and bus voltage correction had been addressed in contingency operation. Fuzzy logic membership functions were employed to compromise among conflicting evaluation factors. A Newton-Raphson load flow was integrated into the system to verify the soundness of the solutions in case of doubt. The prototype was tested on a portion of MERALCO's distribution network which consists of 12 distribution substations with 25 buses and 24 lines. Within its problem domain, the prototype performed as expected.