A Morphological Method for Discriminating of Inrush Current from power system fault in Power Transformers

This paper presents an accurate method fordiscrimination between transformer inrushcurrent and power system fault. Analysis ofthe waveform of the current transient signaland calculated flux at the secondary windings is performed in order to determine whether the current is a fault or a magnetizing inrush current. Due to the symmetrical relation between the inrush current and related flux (at three phase), the proposed algorithm deals with a morphological technique in detection process. The proposed discriminator criterion is tested by various types of magnetization curves, different energization times and several various power system faults. The MATLAB/EMTP simulation results show that the proposed technique offers fastresponses (half power frequency cycle) in protection and accurately discriminate between the magnetizing inrush current and power system faults.

کلیدواژه ها:

Transformer protection ، Inrush current ، power system fault ، Morphology