不同波形对于氧化锌电阻片通流性能的影响分析  

Analysis of Influence of Different Waveforms on Current Performance of Zinc Oxide Varistor

作　　者：王博闻 方针 李化[2] 胡建平 王哲豪 付志瑶 陈宝辉 彭永晶 WANG Bowen;FANG Zhen;LI Hua;HU Jianping;WANG Zhehao;FU Zhiyao;CHEN Baohui;PENG Yongjing(State Key Laboratory of Disaster Prevention&Reduction for Power Grid Transmission and Distribution Equipment,State Grid Hunan Electric Power Company Disaster Prevention and Reduction Center,Changsha 410129,China;State Key Laboratory of Advanced Electromagnetic Engineering and Technology,Huazhong University of Science and Technology,Wuhan 430074,China)

机构地区：[1]电网输变电设备防灾减灾国家重点实验室,国网湖南省电力公司防灾减灾中心,长沙410129 [2]华中科技大学强电磁工程与新技术国家重点实验室,武汉430074

出　　处：《高压电器》2020年第10期197-204,共8页High Voltage Apparatus

基　　金：国家电网公司科技项目(5216A01700UD)。

摘　　要：氧化锌电阻片在大电流冲击下会出现电流、热量分布不均匀而导致内部应力增大。文中搭建了试验平台测试了不同波形下电阻片失效的临界能量密度,试验表明2 ms方波的临界能量密度要明显高于4/10μs冲击测试,能量密度约为其的1.76倍。不同波形下失效现象比例存在一定的区别,2 ms方波冲击下电阻片会出现穿孔现象,4/10μs冲击测试下,电阻片主要为侧面闪络与破裂两种失效现象。搭建了磁滞回线测试回路,获得了氧化锌电阻片在不同频率下磁导率。试验表明随着频率从100 Hz增加到10000 Hz,氧化锌电阻片的磁导率从267下降到52。建立有限元仿真模型,仿真分析了不同电流波形下电阻片的通流特性。仿真表明:冲击电流下(4/10μs)热应力的幅值远大于2 ms方波下的热应力幅值,在通流能量接近时,约为其的4000倍。分析表明氧化锌电阻片在高频率冲击电流下内部应力作用更为显著。The internal distribution unevenness of current and heat in zinc oxide varistor under high current im⁃pulse,resulting in an increase in internal stress.In this paper,an experimental platform is built to acquire the criti⁃cal energy density of the failure of the varistor under different waveforms.The experimental results indicate that the critical energy density of the 2 ms square wave is significantly higher than that of the 4/10μs impulse,which is about 1.76 times.There is a certain difference in the proportion of failure phenomena under different waveforms.Under the 2 ms square wave impulse,the varistor will have puncture phenomenon.Under the 4/10μs impulse experiment,the varistor mainly has two failure phenomena:flashover and cracking.An experimental circuit of hysteresis loop is built to obtain the magnetic permeability of the zinc oxide varistor under different frequencies.The results indicate that the permeability of the zinc oxide varistor decreases from 267 to 52 with the frequency increases from 100 Hz to 10000 Hz.The finite element simulation model is established to simulate the current characteristics of the varistor under differ⁃ent current waveforms.The simulation results show that the amplitude of the stress under the 4/10μs impulse current is much larger than that under the square wave of 2 ms,which is about 4000 times when the energy density is close⁃ly.The energy density under different impulse currents is quite different.The analysis shows that the internal stress of zinc oxide resistors is more significant under high frequency impulse current.

关 键 词：氧化锌电阻片 电阻片失效 大电流冲击 磁导率 有限元仿真 热应力 

分 类 号：TM862[电气工程—高电压与绝缘技术]