Benefiting from their good mechanical and electrical properties, epoxy resin materials are widely utilized in the field of high-voltage electrical insulation devices. However, with the increase in voltage levels of equipment, the epoxy resin materials used for insulating pull rods in high-voltage electrical equipment are facing increasingly severe challenges. This study enhanced the mechanical and insulating properties of epoxy resin materials by molecular structure regulation, composite incorporation and formula optimization. The tensile strength, bending strength and impact strength of the epoxy resin materials with molecular structure regulation increased by 20.6%, 8.5% and 42.1%. The breakdown strength successfully increased from 27.6 kV/mm to 29.9 kV/mm. After combining with the modified Al₂O₃ nanofillers, the breakdown strength, surface resistivity and volumetric resistivity of the composite further improved to 35.8 kV/mm, 2.7 × 10¹⁶ Ω and 5.8 × 10¹⁷ Ω·cm. The insulating pull rod prepared by this method achieved a flashover voltage of 18.5 kV, meeting the requirements for both insulating and mechanical performance of a prototype of 200 kV high-voltage direct current floor tank-type high-speed mechanical switch. This study can provide important support for the optimization of epoxy resin material formulation design and the development of epoxy-resin-insulating pull rods.

As a control structure, the magnetic repulsion device is applied in the high-speed switch hydraulic operating mechanism. It must not only move quickly but also stop precisely. The repulsion disk is subjected to high impact loads, resulting in the phenomenon of fracture and damage. In this paper, the magnetic repulsion value of the engineering prototype was obtained through simulation. A super-elastic material was selected as the buffer, and impact dynamics simulation was carried out. A double-repulsion-disk structure was designed, which reduced the structural impact stress and satisfied the operation time of less than 2 milliseconds. This realized redundant design and improved the reliability of the high-speed switch hydraulic operating mechanism, which is of great significance for the safe operation of high-speed switches.