Impedance-based ground fault location for transmission lines

Impedance-based fault location methods are widely used due to their simple mode of operation and relatively low cost. However, their performance suffers from factors such as fault impedance, pre-fault load current, and remote infeed. Although significant improvements have been made by compensating these effects, the presence of unreliable zero-sequence current always presents a challenge to those conventional methods. The algorithm proposed in this paper for a one-terminal fault location method using a new superposition current in conjunction with a reactance method offers significant improvement. Different types of line modeling are represented to show their effects on the fault location estimation. Furthermore, comparative test results of the proposed one-terminal method with conventional two-terminal methods are also presented. The simulations are performed in EMTP-RV and the signal processing is conducted by using MATLAB.