Fault identification in distribution systems using maximum overlap wavelet decomposition

摘要

This paper presents a novel voltage-based protection element using MODWT wavelet coefficients. This helps improve the sensitivity of existing current-based protection which can be subjected to sensitivity issues given the evolving distribution grids with multiple generation sites. The analysis of the voltage transient immediately after a disturbance can provide much useful information about the nature of the disturbance, which may otherwise be hidden. Therefore, augmenting transient based fault detection to existing techniques can improve the system protection. The proposed algorithm analyses the relative and individual content of high and low wavelet-level coefficients to reliably detect faults, and not trigger during non-fault disturbances like capacitor switching. The performance of the element is validated using results from power system simulation models and field event reports.