Análise da aplicação da função sensitive ground fault (SGF) em redes de média tensão

Abstract

High impedance fault detection has long challenged engineering and its protective equipment. High impedance faults (HIF) occur when a conductor comes into contact with objects with a high resistance, which do not result in significant current increases, being masked by the load current. This type of fault cannot be detected by traditional overcurrent protection devices. HIFs are a public safety issue due to the human risk involved. In this sense, HIF detection methods have been the focus of interest in several studies. Several manufacturers use different types of algorithms to detect these faults, but there is still no system that detects 100% of HIFs. The objective of this work is to model high impedance faults in a medium voltage distribution system, through computational software, using data from oscillograms contained in the literature, in order to reproduce characteristics that are close to the real ones generated in the field. occurrence of the type of fault in question, and in addition, another objective is to model a protection relay, which has the SGF function incorporated, in order to validate the detection of simulated faults. The results obtained in the modeling of the faults presented the expected characteristics, when compared to the real characteristics of HIFs and the modeling of the SGF function detected all occurrences of simulated HIFs. [resumo fornecido pelo autor]