Suppression of Metal Particle and Surface Flashover by Dielectric Functionally Graded Spacers

This study explores the efficacy of permittivity functionally graded material (<tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\varepsilon$</tex>-FGM) spacers in suppressing metal particle motion and surface flashover in AC Gas-insulated switchgears (GIS). The <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\varepsilon$</tex>-FGM spacer, characterized by a four-layer permittivity distribution, was fabricated utilizing a gravity settlement method. Data indicate a migration of metal particles move towards the uniform spacer under the influence of the Coulomb force, leading to a reduction of the flashover voltage by as much as 12 %. However, using the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\varepsilon$</tex>-FGM spacer enhances the flashover voltage by 10 %. Metal particles situated in proximity to the <tex xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">$\varepsilon$</tex>-FGM spacer experience Coulomb forces that repel them from the spacer, resulting in the particles moving away at an accelerated speed. Consequently, the flashover voltages are comparable to scenarios without particles.