Non-destructive testing high-pressure wall-penetrating sleeve based on terahertz frequency modulated continuous wave

Wall penetrating porcelain sleeves are used for power distribution equipment and high-voltage electrical appliances in power stations and substations. They are used for wires to pass through grounding partitions, walls, or electrical equipment casings, supporting conductive parts to insulate them from ground or the casing. The sleeve is composed of porcelain parts, metal accessories, installation flanges, and conductive bars (rods), etc. Due to long-term use, porcelain components may experience cracking, aging, and other phenomena, posing a serious threat to the safe and stable operation of the power system. This article analyzes the defects, material parameters, and thickness of ceramic sleeves using a terahertz frequency modulated continuous wave system. We conducted tests on both standard samples and actual ceramic sleeves. The research results of this article provide a basis for the application of terahertz technology in nondestructive testing of power systems, which can achieve on-site testing of high-voltage ceramic bushings and ensure the safe operation of power systems.