High Impedance Fault Detection Using DWT for Transmission and Distribution Networks

The objective of intelligent electronic devices in grids running fault detection algorithm is to evaluate the special features in patterns of the voltages and currents samples taken at strategic points for transmission and distribution networks and detect if a fault has occurred. Fault detection is necessary to improve power grid reliability and efficiency for safe power supply transmission and distribution. High Impedance Faults (HIF) are an important type of power system faults that are difficult to be detected by conventional over-current protective relays because of their very low fault currents. High impedance faults (HIFs) creates lot of transients in the power system and can result in equipment damage and electrical shocks. Therefore special methods have to be developed and utilized in order to detect them quickly. DWT is an effective method for HIF detection as it is capable of extracting transient information in both frequency and time domains simultaneously. High frequency transient energies is shown to be useful for accurate fault detection and classification.