The location of High-Impedance Faults (HIFs) is an increasingly relevant reliability
issue in the electric power distribution industry. The development of practical and accurate
single-terminal fault locating methods is vital for reducing the time and cost of restoring
long-duration interruptions. However, the need to estimate both the parameters of the fault
model and the fault current signal can compromise the accuracy and practicality of existing
HIF location methods. This is due to the larger number of parameters that need to be
estimated when a HIF model is included in the formulation, as well as the assumption that
load currents at the network bars are constant during a pre- and post-HIF interval. In other
words, the use of the fault model and waveform implies that the location method depends on
the random characteristics and magnitudes of the fault current, which are determined by
environmental, technical conditions, and the type of surface where the HIF occurs, including
even the way the contact between the surface and the conductor occurs. This thesis proposes
a fault-model-free iterative method based on zero-crossings of signals to locate HIFs in
overhead distribution networks. Two insights on voltage signal relationships are provided to
eliminate the need to estimate fault model parameters and the fault current signal in the HIF
location process. The first insight is based on zero-crossings of the calculated voltage drop
per unit length signal to estimate two parameters of the voltage signal at the fault point. The
other insight is based on the zero-crossing of the voltage signal at the fault point, where the
two parameters were previously estimated, to calculate the fault distance from the k-th node.
Simulation results on a modified IEEE 34-node test feeder validate the high accuracy and
robustness of the proposed method, considering the effect of various factors on the
estimation of the HIF distance. Additionally, the convergence performance of the proposed
method is evaluated.
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