Abstract
The ZnO surge arrester with a series gap has been generally applied to the 6 kV power distribution systems in Japan, and recently also, line-insulator including ZnO elements has been applied with the improvement of these elements. However, the performance characteristics of them have still not been sufficiently clarified for a long period of usage and so the deterioration diagnostics have not been established in the hot-line. Therefore, it is desired to present the changes in the characteristics for usage over a long period, and then establish the diagnostic method of their deterioration.
We have investigated the leakage current, lmA operation voltage and residual voltage.
In this paper, for investigating the deterioration of the arrester, the changes in the leakage current, the divided voltage of ZnO elements were measured with elapsed time after each set of 50 operations of the arrester operated repeatedly by a large impulse current.
As a result, it was found that the leakage current and divided voltage of ZnO elements increased with the number of operation times. Consequently, it was found that the moisture of ZnO elements affects the characteristics of the leakage currents
