Evaluation method of transformer damage from auto-reclosing scheme in power distribution system

This paper presents how to evaluate the transformer damage caused by an auto-reclosing scheme in a power distribution system. We describe a quantitative relationship between the reclosing scheme and the number of fault currents flowing through a transformer using the probability of a reclosing success/failure. The transformer damage from the reclosing scheme is formulated as an index that forms a weight function and a damage function. This index is associated with the number of reclosing attempts, a reclosing deadtime and a transformer functional life. In the case studies, the transformer damage is simulated for the probability of a reclosing success. We carried out an evaluation of transformer damage using KEPCO´s operation data