The paper analyses the principles of distinguishing internal faults current from inrush current and their defects at the present time on the basis of investigating widely the existing papers on identification of inrush current. According to the characteristics of inrush current a series of new approaches of discrimination inrush current by utilizing extenics set is presented. Meanwhile, using the oscilloscope data from dynamic test the paper verifies this scheme. The result shows that inrush identification scheme making use of extenics theory overcomes some deficiency of traditional protection, betters performance of transformer relaying.
|