Majid Dashtdar - Electrical Engineering Department, Faculty of Engineering, Islamic Azad University, Bushehr, Iran
Masoud Dashtdar - Electrical Engineering Department, Faculty of Engineering, Islamic Azad University, Bushehr, Iran

In this paper, a discrete wavelet transform has been used to process the signal in order to locate the network transmission fault. In fact, the basis of the work is based on the information recorded before the fault at the end of the line and after the fault at the beginning of the line received by the relay. Obviously, high-frequency components are created at the time of the fault, which is a way of extracting these components using a wavelet transform. In this design, wavelet transform is also derived from relay current data. In the following, we can accurately estimate the exact location of the fault in the transmission network by extracting the minimum and maximum components of the approximate and partial components of the signal before and after the fault (pre-fault and post-fault). The simulation results reveal that the minimum and maximum extracted components are highly dependent on the fault resistance. Hence, in order to increase the fault resistance, the level of signal decomposition has to be increased so that the algorithm is not compromised. Eventually, the proposed method is tested on the transmission network of 735 kV at different distances of the transmission line, which indicates that the proposed algorithm can accurately estimate the fault distance, depending on the type of fault (including low impedance and high impedance fault) by changing the signal decomposition level.

Fault Location, wavelet transform, high-frequency component