Based on the experimental results--the trap distribution characteristic and flashover performance of Alumina ceramic samples in vacuum which were prepared by different ways, this paper try to discuss the relationship between the trap distribution and the flashover performance of Alumina ceramic sample. Comparing with the flashover performance of the insulator sam-pies in vacuum, it was found that the trap distribution could influence on the flashover performance. Based on our investigations, the relationship between the trap distribution and the flashover performance was discussed. It seems that the trap distribution maybe, the better parameter to reflect the flashover performance, and the further more works are needed to set up the relationship between the trap and the flashover.

The interference voltage in the secondary cables through high voltage bus, current transformer and capacitance coupling voltage transformer caused by lightning striking the region of transmission line neighboring substation were analyzed EMTP software package is used to calculate this problem. The equivalent models of different equipments, especially the transient models of current transformer (CT) and capacitance coupling voltage transformer (CCVT), were discussed The analysis results stated that the interference voltage in file secondary cables caused by lightning striking the region of transmission line neighboring substation is serious, which must be paid attention to by electrical engineers.

It was considered that the trap distribution of alumina ceramics could affect the flashover performance of insulators. This paper investigated the trap distribution of alumina ceramic samples with different additives and different sintering temperature respectively. Experimental results show that the additives and sintering temperature play an important role on the trap distribution of alumina ceramics respectively, especially on the trap energy distribution, and they affect the trap distribution of alumina ceramics significantly.

This paper has investigated the thermally stimulated current (TSC) of Alumina ceramics using a uniform electrode system. Experimental results with different Alumina ceramics showed that TSC characteristics of the samples prepared with varied metal oxide additives was different. The trap distribution parameters were calculated from TSC curves, the calculation results show that the additives significantly influence the trap distribution.