Early detection and accurate fault location algorithm for medium voltage transmission lines using transient analysis for current measurements

This paper presents an accurate method to determine fault location on Transmission Lines (TLs). The proposed method utilizes information contained in the voltage and current signals that measured at both TL terminals; This data is taken prior to and during the fault time period. The method is based on using the fault current formula during the transient period for calculating the AC component of fault currents; and then the differential equation is applied to obtain an accurate fault location on the TL. The Fault Location (FL) algorithm can be divided into three modules: fault detection module, estimation of the sinusoidal AC component of fault currents module, and fault location module. Several fault situations have been evaluated considering different simulation parameters such as fault resistances, fault inception angles, fault locations and fault types. The results have proved that the proposed method is accurate, and robust. It can be applied to distribution and sub-distribution TLs, independent of fault type and location, insensitive to the variation of fault resistances and fault inception angles and no need for traditional low pass filter. Furthermore, it is useful to avoid the effect of Current Transformer (CT) saturation condition.