MOA在多脉冲冲击下老化性能研究  

Research on Aging Properties of Metal Oxide Arrestor under the Multi-pulse Shots

作　　者：李鹏飞[1] 杨仲江[1] 曹洪亮[1] 赵军 王祥 

机构地区：[1]南京信息工程大学中国气象局气溶胶与云降水重点开放实验室,江苏南京210044 [2]北京市雷电防护装置检测中心,北京100176

出　　处：《中国电力》2016年第1期69-74,共6页Electric Power

基　　金：国家重点基础研究发展计划“973计划”资助项目(2014CB441405);国家自然科学基金资助项目(41075025)~~

摘　　要：ZnO压敏电阻是电力系统金属氧化物避雷器(MOA)的核心器件。ZnO压敏电阻受潮是影响其性能蜕变的重要因素。借助湿热箱和多脉冲平台,研究ZnO压敏电阻在受潮条件下的性能变化。结果显示:受潮时压敏电压(U_(1mA))超出±10%标准范围的速度是干燥时的3倍,30%的合格样品在一次多脉冲冲击后失效。干燥时多脉冲冲击下U_(1mA)与泄漏电流(I_L)均呈现平稳期减短,末期变化速度增快的趋势。通过ZnO压敏电阻的理化特性分析发现,压敏电阻受潮后水分子进入晶界层发生化学反应,使具有双肖恩特基势垒结构的晶界层发生畸变。多脉冲冲击下,其内部晶粒热导率急剧下降,部分热导性能较差的晶界首先发生热平衡状态转变,晶界区电荷量产生变化,最终伏安特性发生蜕变。ZnO varistor is the key element in Medal Oxide Arrestors（MOA） of power systems. The moisture level is an important factor for the property of ZnO varistor. The properties of ZnO varistor under moisture condition are studied by use of damp heat box and multi-pulse platform. The results show that the speed of the varistor voltage（U1mA） exceeding ±10% in the damping scenario is three times faster than that in dry condition. 30% of the samples become failed after one multi-pulse shot. In dry scenario,the plateau of the U1mA and the IL becomes short and the aging speed accelerates. Through analysis of the physicochemical properties, it is found that after the varistor damped, the water molecules come into the inter-granular layer and set off a chemical reaction, which makes a deformed double Schottky barrier structure. Under multi-pulse shots, the thermal conductivity of ZnO varistor’s internal grains drops sharply, and some inter-granular layers with the poor thermal conductivity firstly change from thermal equilibrium into imbalance, resulting in the change of the quantity of electric charge in grain-boundary area and the metamorphosis of the voltage characteristics.

关 键 词：避雷器 ZNO压敏电阻 多脉冲 潮湿 静态参数 理化特性 

分 类 号：TM862[电气工程—高电压与绝缘技术]