Applicability of surface functionally graded materials for flashover mitigation: from vacuum to compressed SF6 gas

作者：Chao Wang, Yu-Long Yang, Cheng‐Lin Hou, Wendong Li, Sile Chen, Zhaoquan Chen, Guanjun Zhang · 发表于：Surface and Coatings Technology · 年份：2025 · DOI：10.1016/j.surfcoat.2025.132166 · 被引用次数：5 · 研究领域：High voltage insulation and dielectric phenomena、Power Transformer Diagnostics and Insulation、Aerosol Filtration and Electrostatic Precipitation

Surface functionally graded materials (SFGMs) exhibit promising prospect in flashover mitigation of solid insulation in high-voltage apparatus. The construction methods and their applicability of SFGMs in various scenarios are systematically investigated in this work. Coating materials with different functional fillers were prepared to fabricated different types of SFGMs. Flashover testing results show that coating with graded permittivity (ε-SFGM) and coating with graded permittivity / conductivity (ε/ σ-SFGM) exhibit excellent electrical strength enhancement effect in compressed SF 6 gas at power frequency. In contrast, the improvement effect of SFGMs are limited in vacuum. Only ε/ σ-SFGM constructed by SiC fillers shows a better flashover mitigation effect in vacuum due to the dissipation capability of surface hetero-charge. σ-SFGM constructed by carbon nanotube fillers would deteriorate surface electrical strength both in SF 6 gas and in vacuum due to its excessive conductivity. Furthermore, numerical simulations were conducted to build the relationship between SFGMs construction methods and flashover threshold both in vacuum and compressed SF 6 gas, which are in agreement with the experimental results.