Abstract: Abstract:In an 110kV substation, when the 110kV line failed and relevant beaker tripped, the automatic bus transfer equipments of the substation did not act, and related transformer and 110kV bus were cutout. Using the theoretical analysis and logic verification method, the accident was analyzed and discussed. The preventive measures in operation and maintenance were pointed out. The results in this paper provide reference for design and operation of the automatic bus transfer equipments.

Key words: Keywords:automatic bus transfer equipment, rejecting act；technical measure