ZnO压敏电阻冲击电流寿命分布的试验研究

Experimental study of the life distribution of ZnO varistors subjected to surge current cycles

对氧化锌压敏电阻(MOV)样品进行了最大放电电流下的冲击电流寿命试验,得出了每只样品在失效前所能承受的冲击次数;通过对大量样品冲击电流寿命的统计分析,证明了MOV在冲击电流作用下的失效率服从威布尔(weibull)分布,从而为确定MOV的失效前平均寿命和保证寿命提供了依据。

Tests were performed to evaluate the life of zinc oxide varistor （MOV） specimens subjected to surge current cycles, with the employed surge current equaling to the maximum discharge current of the MOV. The number of surge current cycles each specimen can bear before failure was obtained. Based on the statistical analysis of the obtained life data of lots of MOV specimens, the failure rate of MOV subjected to surge current cycles is found to follow a Weibull distribution. This finding provides basis for the determination of the average life and guarantee life of MOV.