Error Sources in Impedance‐Based Fault Location

This chapter utilizes a power system model to show the sensitivity of fault‐locating algorithms to errors stemming from inaccurate input data and incorrect application. Understanding the impact of these error sources on fault location will help the user make decisions in the field when a fault occurs in their system. The chapter also utilizes the power system test model to study the impact of an unknown value of earth resistivity on impedance‐based fault location algorithms. Impedance‐based fault location algorithms require the positive‐ and zero‐sequence impedances of a transmission line to estimate the distance to a fault. The chapter discusses different approaches to reduce fault location error stemming from applying impedance‐based fault location algorithms to a non‐homogeneous line. Series compensation is another technique used by utilities to increase the power transfer capability of transmission lines. Impedance‐based fault location algorithms expect fault location to be calculated when the fault has reached steady state.