摘要
为研究多脉冲电流冲击特性,设计一台十脉冲电流冲击设备,其主要由8/20μs波形发生器,高压开关以及由D触发器组成延时电路等组成,利用其对压敏电阻进行冲击试验,试验表明十脉冲冲击下,ZnO压敏电阻U_(1 mA)变化呈现初期快速减小,中期平缓,后期快速减小趋势。泄漏电流变化呈初期缓慢上升,中期进入平缓区,后期快速增大直至损坏。与单脉冲冲击下,泄漏电流变化规律相同,但泄漏电流变化的平缓区域远远小于单脉冲冲击下的平缓区域。通过对压敏电阻热行为分析发现,在十脉冲冲击下,ZnO压敏电阻内部晶粒热导率开始下降,部分热导性能较差的晶界首先由热平衡状态转入热不平衡状态,晶界区电荷量发生变化,最终伏安特性发生蜕变。
In order to research the impact performance of multiple pulses current, design an impactdevice of ten pulses, it consist of 8/20 /xs waveform generator, high voltage switch and time delaycircuit which consist of D flip-flop. The impact test show that the aging rate of ZnO varistors obviouslyspeeds up under the impact of multiple pulses. The study shows that the U1 ,a of ZnO varistor is rapiddecrease in the early times, the U1 mA changes gently at the medium, at the later the decrease of U1 mAbecome faster. The leakage current is slowly rising at first, the leakage current rise slowly at themedium. At the later the leakage current rising quickly and until the ZnO varistor is failure. Comparewith the result of ZnO under the one impulse, the changing of leakage current is the same, but the timeof leakage current is larger at the medium. The heat conductivity of grains becomes to decrease and thepart of grain boundary which has the bad performance from the thermal equilibrium state to thermalimbalance, the charge of the grain will be changedtransformed., eventually, the V-I characteristic will betransformed.
出处
《电瓷避雷器》
CAS
北大核心
2017年第1期14-18,共5页
Insulators and Surge Arresters
基金
国家重点基础研究发展计划(973计划)资助项目(编号:2014CB441405)
国家自然科学基金项目(编号:41175003)
江苏高校优势学科建设工程资助项目(PAPD)资助
关键词
多脉冲
肖特基势垒畸变
自然闪电
热应力
冲击老化
multiple pulse
Schottky barrier
natural lightning
thermal stress
impulse aging
