8/20脉冲对ZnO压敏电阻器工频耐受性能的影响

Effect of Repeated Pulses of 8/20 Waveform on Power FrequencyVoltage Withstand Capacity of ZnO Varistors

通过试验,分析了8/20脉冲次数及电流峰值对ZnO压敏电阻工频耐受性能的影响。在脉冲次数及电流峰值不同的情况下,电阻体内部发生结构性变化,导致其工频耐受性能发生变化。当脉冲电流峰值未超过某一临界值时,工频耐受时间随着冲击次数的增加而延长,超过此临界值时,工频耐受时间随着冲击次数的增加而缩短;在8/20脉冲次数一定的条件下,工频耐受时间也随电流峰值的递增呈现先延长后缩短的趋势。

Through experimental, the effect of 8/20 pulse number and current amplitude on power frequency voltage withstand capacity of ZnO varistors is analyzed. With different pulse number and current amplitude, the texture change take place in varistor, leading to variation of its power frequency voltage withstand capacity. At current amplitude below a certain critical value the power frequency voltage withstand duration increases as the pulse number raises, meanwhile beyond the critical value it will be decreased as the pulse number raises. At a given pulse number, the power frequency voltage withstand duration tend to increase at first and then decrease as the current amplitude raise.