Resumo:
Fault location algorithms present different formulations, data requirements, and parameters
that make them applicable or not to a specific scenario. Understanding these requirements
and the characteristic errors in different scenarios is essential to enable the selection of the
most appropriate approach. This work presents several fault location algorithms based
on phasors from one and two terminals and analyzes their performance in cases of actual
faults and simulated faults in Extra High Voltage Transmission Lines.
The presented algorithms were implemented in a software in the MATLAB® environment
for analysis of faults simulated by ATPDraw™ and for the analysis of actual faults
using files generated by Protection Relays and Digital Fault Recorders. The algorithm
performance results were compiled into graphs for analysis. The performances were
evaluated for different faults types and different sources of error.
The one-end fault-location algorithms used in this study have features to reduce the error
caused by fault resistance combined with load current and system non-homogeneity. The
two-end fault-location algorithms solve this problem and have features to reduce error
due to synchronization failure. However, algorithms that use the symmetrical components
approach can present considerable errors in the case of non-transposed transmission lines
or lines with long non-transposed sections. For these cases, matrix-based approaches were
used.
The theoretical presentation of the algorithms and the results of the simulations make it
possible to indicate the most viable solution based on parameter requirements, available
input data, and the effects of different error sources present in each case, improving
fault location estimates. Tables presenting the effects of the error sources and input
data requirements have been developed to support this choice. A more accurate fault
location estimate reduces the time and cost for transmission line inspection, reducing
system restoration time, contributing to the safety of people, the environment, and
the transmission system, as well as reducing potential financial penalties for equipment
unavailability or compensations fines.
