一种瓷绝缘子釉面电蚀加速老化试验的新方法

A New Method for Glaze Erosion and Accelerated Aging Test of Porcelain Insulator

为了对瓷绝缘子进行加速老化试验研究,提出了一种基于石墨涂层的釉面电蚀试验方法。将鳞片石墨和液体胶水按1:1.2的质量配比配制成石墨层,采用含多个镂空菱形网格的涂刷模具将其涂覆于绝缘子伞裙表面,在石墨层两端的伞裙根部及伞沿分别布置高、低压电极,通过高压试验回路对其施加电压,可在被试伞裙表面产生持续稳定的电弧,从而使釉面发生电蚀。采用该方法对支柱瓷绝缘子试品进行了电蚀试验,分析了电弧发展过程、电弧电流特性、红外热像等试验现象及电蚀效果,通过孔隙性试验及扫描电镜试验验证了石墨电蚀法的有效性。结果表明,石墨电蚀法能够快速有效地使瓷绝缘子釉面发生电蚀,釉面电蚀会导致绝缘子介电强度和机械强度的下降,最终引起绝缘子老化失效。研究结果可为瓷绝缘子加速老化试验提供参考。

In order to study on the accelerated aging test of porcelain insulator, a test method of electrical erosion for glaze based on graphite layer was proposed. The graphite layer was made up with flake graphite and liquid glue according to a quality ratio of 1：1.2 and it was coated on the surface of the insulator shed, using a brush mold which contains multiple hollowed-out rhombic grids. The high voltage electrode and the grounding electrode were arranged at shed root and shed edge respectively. Sustained and steady arcs can produce on tested shed with applied voltage, so as to lead electrical erosion to the glaze. The erosion test based on the proposed method was conducted on a porcelain post insulator sample, the test phenomena including arc development process, arc current characteristics, infrared thermogram, and erosion effects are analyzed. Porosity test and scanning electron microscopy （SEM） test were conducted to verify the validity of graphite erosion method. The results indicate that electrical erosion may occur to the glaze quickly and efficiently by graphite erosion test. Glaze erosion may cause a decline in the dielectric and mechanical strength of the porcelain insulator, which lead aging and failure to the insulator eventually. The research results can provide a reference to the accelerated aging test of porcelain insulator.