Effect of Moisture on the Multiple Lightning Strike Resistance of ZnO Valve Discs
The ZnO valve is the core component of a lightning arrester and is susceptible to moisture intrusion in the en-vironment and severe damage under multiple lightning strikes.In this paper,the effect of moisture on the multiple lightning strikes of ZnO valve discs is investigated.Firstly,an experimental platform for ZnO valve discs multiple light-ning strikes and an artificial moisture experimental platform were built.Then,samples were prepared in different moisture states,four lightning strikes experiments were conducted on the samples,and the DC parameters and infrared temperature rise of the samples during the experimental process were tested.Finally,based on the impact surface temperature distribu-tion and impact thermal performance parameters of the samples,the impact damage forms were calculated,and the changes in the impact thermal properties of the damped valves and the damage caused by thermal stress were analyzed in conjunction with the microstructural changes of the samples.The experimental results show that the moisture of the valve disc accelerates its multiple lightning damage rate,and the damage rate is up to 7.5 times that of the normal valve disc;the impact infrared temperature rise of the damped valve disc increases but is more uniformly distributed,and the maximum temperature rise is 1.75 times that of the normal valve disc;the deterioration of the valve disc by moisture is mainly caused by the high electrical conductivity resistance channel formed by the internal microcracks and moisture to-gether,and can cause reversible defects on the valve disc that recover with drying and Corrosion irreversible defects.
multiple lightning strikeszinc oxide valve discsdeterioration by moisturelightning strike tolerancemcrocracking
万方数据
维普
