Insulation degradation affected by micron metal particles attached on epoxy surface: charge accumulation and flashover voltage

Abstract

The micron metal particles are inevitable produced in long-term operation condition of HVDC SF6 insulated apparatus, which could frequently cause the surface discharge. Degradation of long-term surface discharge will be a severe threat to the insulation strength. Aiming at this problem, the surface charge accumulation and flashover voltage of epoxy itself before and after discharge degradation by particles were compared in this paper. The composition after degradation was measured by EDS and FTIR. The microstructure was observed by SEM. The roughness was measured as well. The trap distribution was measured by SPD. The mechanism of degradation and its effect on insulation characteristics were analyzed. The results show that the surface charge accumulation increase 3 times after degradation. Besides, flashover voltage decreases 19% after degradation. The smoothly surface after degradation decrease the trap energy level for 14%, which might be the change reason of surface charge accumulation and flashover voltage. This paper can offer as a reference for the effect of micron metal particles on insulation degradation in SF6 gas insulated equipment.

Effect of Y2O3-Al2O3 Additives on the Microstructure and Electrical Properties Evolution of Si3N4 Ceramics

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