Non-linear High Impedance Earth Faults Locator for Series Compensated Transmission Lines

Series capacitors cause some phenomena which seriously affect impedance based fault locators. Moreover, non-linear high impedance earth faults (NLHIEF) increase fault locator problems because of their distinguished effects such as: arcing features, harmonic content caused by the ground fault nonlinearity, and the random intermittent features. This paper deals with non-linear high impedance earth fault location on high voltage series compensated lines with respect to why the other methods known in literature can't be applied. The proposed algorithm uses two terminal measurements; however those data do not require full synchronization. Each side uses discrete Fourier transform to calculate zero sequence current values and then one terminal relay sends its value to the other one, to locate these unsymmetrical ground faults. Upon extensive simulations for testing of the proposed scheme while varying the compensation percentage level, its performance ensures acceptable accuracy.