Análisis espectral para la detección temprana y activación de protecciones ante fallas a tierra en redes eléctricas de media tensión con neutro aislado mediante modelado industrial

Abstract

This document focuses on spectral analysis for early detection and protection activation against ground faults in medium-voltage electrical networks with isolated neutral, using industrial modeling and simulation in specialized environments. The main objective is to improve detection sensitivity and response speed in low-current events that do not trigger conventional protections. The IEEE 13-bus test system is implemented in PowerFactory 2021 and adapted to include unbalanced PQ-type loads, Y–Y transformers with isolated neutrals, and lines modeled with ground capacitance. A single-phase-to- ground fault is simulated at bus 634, and electrical signals are exported to MATLAB, where continuous wavelet transform (CWT) techniques are applied to compute spectral energy and detect the transient associated with the fault. The 3·U₀ signal proved to be the most effective for automatic detection, with a clear, early response compared with the other variables analyzed.