Arc welding equipment - part 3 : arc striking and stabilizing devices iec 60974 - 3 : 2003 ; german version en 60974 - 3 : 2003 弧焊设备.第3部分:电弧闪击和稳弧设备
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The shorter the interval between the two pulses of the current wave , the fewer strikes the varistors can endure . at the same time , the dc ljima changes fast - slowly - fast alone with the experiment continuing . microstructual disorder , such as variations in the height of the electrostatic potential at grain boundaries and electrode protrusions into the zinc oxide varistors , causes substantial temperature rise in a microscopic region around the defect and is the source for failure 雷电的多重闪击对雷电过电压保护器件的影响更加严重，本文首次采用不同间歇时间双脉冲电流冲击对氧化锌电阻进行了多次试验，试验表明：氧化锌电阻在双脉冲电流冲击下更容易出现老化破坏现象，间歇时间越短，电阻能耐受的冲击次数越少；此外，直流u _ ( 1ma )值随冲击次数的增加具有快一慢一快的下降过程。
