Principle and application of a new type microprocessor-based fault locator for AT feeding traction system

If a fault occurs in the feeding circuits of an electric traction system, it is very important to find fault location and to remove it immediately for the purpose of ensuring safety for transportation. Because the characteristics of reactance-distance are not linear, we can´t use the method based on impedance or reactance to find the fault location for the autotransformer (AT) feeding system. Hirofumi Fujie (1977) found a kind of method, called ´AT Neutral Current Ratio Type Fault Locator System´, which can measure the fault location. However, this fault locator has the defects of more investment, lower reliability, worse adaptability and accuracy. The authors describe a microprocessor based fault locator which has the advantages of less investment, high reliability, and high accuracy