Changes In Surface Hardness Of Insulators Under High Load Operating Conditions

During continuous high-load operation of power systems, the surface material properties of suspension insulator, a core component in transmission lines for electrical insulation and mechanical fixation, undergo significant changes. When the line current approaches its rated capacity limit, the surface temperature of suspension composite insulator continuously rises, causing a rearrangement of the material's molecular structure and an increase in surface hardness. This physical change directly affects the long-term operational performance of composite suspension insulator.

Ceramic polymer suspension insulator materials experience significant stress at high temperatures, and its glaze gradually densifies under repeated thermal expansion and contraction. Microscopic grain changes caused by temperature cycling increase surface hardness, accompanied by alterations in mechanical strength. The coupling of electrical and thermal stresses generated under a continuous electric field accelerates the aging process of the surface material. Joule heating from leakage current causes a sudden rise in localized temperature; in these high-temperature regions, the material surface is more prone to hardening.