A review paper on inrush fault isolation methods of a three-phase transformer

Transformer is a crucial component of the electrical power system. Usually, using differential protection Transformers are being protected. But whenever a transformer is energized, sometime malfunctioning may take place in the differential protection due to inrush current. Some methods are used to minimize the fault. Those methods are like per-phase method, cross-blocking method, Percent average blocking method and harmonic sharing method. Then fuzzy logic scheme has been used to separate the internal fault from magnetizing inrush current. After that, a differential protection has been used which was based on wavelet packet transform. Then Mathematical morphology based inrush blocking scheme has been used. In this paper comparison are made between per-phase method, cross-blocking method, percentage average blocking method, harmonic sharing method, fuzzy logic, wavelet packet transform based technique and Then Mathematical morphology based inrush blocking scheme.