An Accurate Approach for Detecting and Classifying the HIF in Distribution Systems (Dept.E)

The High Impedance Faults (HIF) are the faults which are difficult to detect by the overcurrent protection relays. In this paper an accurate approach for detecting and classifying the HIF in distribution systems is presented. The proposed approach recognizes the distortion of the current waveforms caused by the are usually associated with HIF. The Discrete Wavelet Transform (DWT) Based pattern recognition is used for extracting the current signal. DWT detects the fault using the absolute sum value of coefficients in Multi-resolution Signal Decomposition (MSD) over one cycle. The signal line to ground, the double line to ground, and the three lines to ground faults are classified using three simple logic functions. The proposed approach is verified by applying several faults scenarios on IEEE-13 node test system. The results confirm that the proposed approach can accurately detect and classify HIF in the systems.