Research On Transformer's Differential Protection And It's Method Of Distinguishing Inrush

Differential protection has been a major protection of transformer in a long time. How to prevent theinrush causing malfunction in differential protection is a key and difficult problem. Many new protectiveschemes of distinguishing the inrush have been put forward around this problem by research worker. Thepaper analyzes the existent means and provides the new algorithms to solve these problems. The majorcombustions of this dissertation are as follows:(1) The characters of stopping principle using double-harmonic are studied.(2) By research to the distinguishing inrush based on current relativity, the characters of this new wayare pointed out.(3) The merits and demerits of the distinguishing inrush using voltage and current are researched.(4) The new principles and means of distinguishing inrush in the past few years are summarized.