Fault Location on Transmission Lines

Fault location techniques for transmission lines can be classified into impedance‐based and traveling‐wave technologies. This chapter focuses on presenting the underlying theory behind impedance‐based and traveling‐wave fault location algorithms. It highlights the motivation behind the development of each fault‐locating algorithm, defines the input data requirement of each algorithm, and identifies the strengths and weaknesses of each algorithm. One‐ended impedance‐based fault location algorithms estimate the location of a fault by looking into a transmission line from only one end. One version of the modified Takagi method uses the negative‐sequence current instead of the zero‐sequence current to account for load. Two‐ended impedance‐based fault location algorithms use waveform data captured at both ends of a two‐terminal transmission line to estimate fault location. Traveling waves contain valuable information about the fault. Algorithms that use them to locate faults are referred to as traveling‐wave algorithms.