Análise da Blindagem Eletrostática por Elementos Finitos de Dispositivo Tipo Gaiola de Faraday para Pinos de Isoladores de Disco

Abstract

High-voltage disc insulators are devices used in power transmission or distribution networks, serving to support the conductive cables while simultaneously providing electrical insulation. These insulators consist of a metal cap, a metal pin, and a glass or porcelain disc. The combined effects of atmospheric pollution, humidity, and intense electric fields on these insulators facilitate the occurrence of electrical discharges on the central region of the pins, accelerating their corrosion and eventual rupture, which can lead to catastrophic failures in the electrical system. In this work, an electrostatic shielding device called the "Faraday Cage for Disc Insulator Pins" was developed to shield the intermediate region of the pins from the effects of external electric fields. Additionally, a super-hydrophobic coating was proposed for the glass surface of the insulators to facilitate the removal of atmospheric contaminants that induce the formation of voltaic arcs directed towards the pin surface. Experimental tests were conducted using a Van der Graaf generator on a pin protected by the first prototype of the device. Furthermore, computational simulations based on the Finite Element Method were performed to analyze the electric field distribution in 2D models of insulator chains subjected to 69 kV voltages. The experimental and numerical results demonstrated that the device effectively prevented electrical discharges in the pin’s most corrosion-prone area, confirming the efficiency of the electrostatic shielding.