High Impedance Fault Analysis of Distributed Power System Network Using Discrete Wavelet Transform

When an energetic primary conductor comes into contact with a quasi-insulating surface, such as a tree, equipment, or structure or it falls to the ground, the occurrence of the high impedance fault becomes quite high. The importance of these previously unnoticeable flaws is that they pose a significant threat to public safety as well as the risk of ignition by arcing fire. The high impedance failure is categorized by a sufficiently high impedance that traditional safety, such as fuses and current relays, does not detect it. Unlike short circuits with low impedance, which involves relatively large fault currents and are easily detectable by conventional over-current protection, these HIFs constitute a small threat to the power system equipment damage. High impedance failures generate current rates approximately in the range from 0 to 85 Amperes. Typically, a HIF shows flashing and arcing at the point of contact. In this paper, high impedance fault is modelled in the MATLAB/Simulink environment and are classified using discrete wavelet transform to implement proper safety scheme in the distribution system.