High impedance fault detection in Distribution System using Wavelet Transform

A High Impedance Fault (HIF) is generated when an overhead power line physically breaks and falls to the ground or when two phases make contact with a solid grounding. Such faults are difficult to detect in Electrical Distribution Systems and often draw small currents which cannot be detected by conventional protection. Furthermore, arcing accompanies high impedance fault, resulting in a fire hazard, damage to electrical devices and risk to human life. This paper presents a technique based on Discrete Wavelet Transform (DWT) for high impedance fault detection in power distribution system. The algorithm is based on a windowing approach of DWT.