Design Of Artificial Accelerated Aging Test For Silicone Rubber Material For The Composite Bushing

High temperature vulcanized silicone rubber material has been the first choice material of composite bushing shed and sheath, because of its excellent hydrophobicity, hydrophobicity transfer and recovery. However, the long-term operation environments of composite bushing include continuous electric field, light,high and low temperature, salt spray, acid rain, dirt, chemical corrosion, humidity and other harsh weather and environmental conditions, that may make silicone rubber composite casing aging. The shed and sheath of silicone rubber composite bushing and composite insulators are the same, so we can draw lessons from theory of silicone rubber composite insulator aging research. The radius of silicone rubber composite bushing is much bigger than the composite insulator in the same voltage grade, and under mechanical stress effect the aging trend may vary.First,the domestic and foreign literature were analysis and summary,and draw out the material force range of parameters of composite sleevel in ANSYS.The aging of different mechanical stresses under different radius sheath is analyzed.,and the analysis results show that under the same mechanical stress, composite bushing is more vulnerable to damage than composite insulator.At the same time, the relevant parameters in the subsequent artificial accelerated aging testing system was determine.Based on the above analysis, we designed a set of accelerated aging test device of Multi- needle for veneer. In order to simulate the sheath situation of silicone rubber composite bushing, the traditional flat plate were changed to the arch, and the test sample on arch electrodes applied mechanical stress. Single needle-plate corona aging test device could not be formed in a large area uniform corona aging on silicone rubber surface, on the basis of this article added two needles to obtain a more uniform aging zone while increasing the discharge energy. The distance between the two pins and the distance from tip to the sample surface after verification confirmed by experiments.Make a Comprehensive analysis of silicone rubber material sample through hardness, hydrophobic, FTIR, SEM and XPS test method. Test results of FTIR showed that the greater the mechanical stress was applied, the less the silicone rubber samples inherently group content, the lower the absorption peak, and during the corona the summit corresponding absorption of oxidation products increased. SEM results showed that with the increase of the test applying mechanical stress, the cracks and holes of the silicone rubber samples increased.At the end of the paper,aiming at the single evaluation index respectively,we carried on the preliminary discussion for the aging condition of multidimensionalparameter evaluation method based on the characteristics of relative change rate. This provide certain theoretical basis for aging evaluation and return of silicone rubber composite sleeve.