ADAPTIVE SINGLE-END SCHEME FOR DETECTING AND LOCATING OPEN CONDUCTOR FAULTS IN HV TRANSMISSION LINES

Abstract

Open Conductor Faults (OCFs) are particularly difficult to be detected and located in HV transmission systems using one-end data. The thesis has introduced a novel solution to that problem as a transient-based integrated scheme to identify and locate all kinds of OCFs (OCF from both sides or from one side while the other side is earthed) at different fault conditions. The proposed scheme unit (PSU) has limited mathematical requirements as it doesn't need to apply any artificial intelligence techniques. It only applies one-level Discrete Wavelet Transform (DWT) decomposition without any communication requirements, which ensures PSU as a promising scheme to be practically implemented. The applied threshold values are calculated adaptively depending on the normalized value of the pre-fault current approximation coefficients without any interference from operators. The achieved results approved that PSU is immune to load changing or load/capacitor switching. It has the capability to detect different types of OCFs within only 1.25 cycles and accurately estimates OCFs location with less than 1% error for faults at distance greater than 5% of the line length. Since the traditional distance relays don't detect or locate OCFs at all, the obtained accuracy is well promising.