Applying Frequency Response method for contact Rails Fault Diagnosing in Ungrounded Electrical Railway System

Abstract General faults in regular electrical railways system could be detect by implementing the specific protection functions such as ground fault or sensitive earth fault. Otherwise, in ungrounded electrical railway systems which using both feeding and return contact rail at the same time, fault detection cannot done with above-mentioned function. Due to recent growth in electrical railway network especially in metropolises, it is an essential requirement to improve operation and safety indexes by using efficient fault preventing and fault clearing method in minimum time. In this applied research, a new fault diagnosing method developed by using frequency response of contact rails system. This technique based on observing pattern changes caused by expected faults such as broken contact rail, contact rail to ground faults on feed or return circuit frequency response.