Failure Analysis in Grounding Systems by Signal Propagation Analysis

Grounding systems play a crucial role in ensuring the integrity and safety of people and equipment in the power electrical system. However, the conventional methodology for evaluating their operational state is based on measurements of grounding resistance or impedance, which alone do not provide accurate information on the operational status of the grids. Conventional measurements are invasive and not capable of identifying localized problems such as corrosion or conductor breakage. In this context, this study proposes a new approach for monitoring the state of grounding systems through the analysis of transient signals. The effectiveness of the proposed approach is evaluated through case studies based on computer simulations using finite element method. The main objective is to develop a methodology that allows identifying defects in grounding systems based on the analysis of transient response and electromagnetic signal reflection parameters. Next, it is intended to use the Wavelet transform to enable identification of patterns relevant to fault detection. The results of the case studies conducted allowed determining the influence of variations in soil resistivity and permittivity on signal propagation and reflection, as well as the need for methodological adaptations to overcome computational limitations. The existence of distinct patterns associated with conditions of intact and defective grounding conductors was also found. Thus, the approach proposed in this work can contribute significantly to the effective monitoring of grounding systems. In the continuation of the research, it is intended to analyze more complex geometries and develop neural networks for classifying characteristic signal signatures associated with normal and defective states.