Effect of Multiple Lightning Impulse Currents on Zinc Oxide Arrester Blocks

초록

Abstract: This paper presents the effect of multiple lightning impulse currents on zinc oxide (ZnO) surge arrester blocks. In order to investigate the dynamic characteristics of ZnO arrester blocks with respect to multiple impulse voltages, we have been designed and fabricated the multiple combination wave generator. The multiple combination wave generator can produce quintuple1.2/50 ㎲ impulse voltages of 100 kV and quintuple 8/20 ㎲ impulse currents of 12 kA. The electrical and physical properties of ZnO arrester blocks were evaluated. The multiple impulse failures of ZnO arrester blocks are mainly caused by the surface flashover. In the case of multple impulse voltages, the charge enhancement near the joined edges of ZnO arrester block and metal electrodes plays a decisive role on the surface flashover or breakdown initiation and developments. Also, it was found that the changes in the residual voltage and quiescent current of ZnO arrester blocks after the injection of the quintuple 8/20 ㎲ impulse currents of 10 ㎄ were markedly occurred.