Development of an object-oriented expert system for multi-period load transfer

In distribution automation, restoration process is done by switching actions of sectionalizing switches and tie switches on the system. The determination of the state of these switches is mainly logical reasoning with less mathematical process. Thus, knowledge-based systems are ideal tools to accomplish the task. In this research, CLIPS is used to develop the proposed system by taking advantage of its object-oriented feature. By applying object-oriented technique, the actual status of a distribution system component can be reflected properly by updating the attributes of all the objects. By referring to the empirical rules of previous work, the distribution system restoration procedure can be divided into three stages: group restoration, zone restoration and load transfer. The unique feature of the proposed expert system is that the variation of load currents is considered. By doing so, the restoration strategies can be more accurate, practical and effective. A simulation on a small distribution system is performed, the results are compared with the same system which has constant load currents.