摘要
为了将频域介电响应法(FDS)用于氧化锌压敏电阻老化状态的无损检测,在实验室环境下对氧化锌压敏电阻进行冲击老化试验,测量其介电频谱,并引入了带直流电导的多驰豫Cole-Cole模型拟合分析氧化锌压敏电阻的介电频谱。通过双驰豫Cole-Cole模型拟合常温下的介电谱发现,其中存在α驰豫过程和β驰豫过程,其对应的活化能约为0.68 eV和0.34 eV,对应着非本征晶间相缺陷驰豫和本征氧空位缺陷驰豫,α驰豫强度Δε_α随冲击次数的增加而增强,而β驰豫过程不受冲击老化的影响;在拟合高温下(393 K)的介电频谱时新发现γ驰豫过程,其活化能约为0.73 eV,对应着非本征晶界面缺陷驰豫,随着老化程度的加深,驰豫强度Δε_γ、形状参数γ增大,驰豫时间τ_γ和活化能减小;直流电导σDC随着冲击次数的增加而变大,其对应的活化能约为0.72 eV,随着冲击次数的增加而减小。因此,可通过修正的多驰豫Cole-Cole模型参数σ——(DC)、Δε_α、Δε_γ、τ_γ、γ和直流电导活化能、γ驰豫活化能综合评估氧化锌压敏电阻的老化状态。
To apply frequency-domain dielectric spectroscopy technology(FDS)to the non-destructive diagnosis of ZnO varistor’s aging state,impulse aging treatment of ZnO varistor was conducted,and the frequency-domain spectra of the sample with different impulse times were obtained in laboratory environment.The multi-relaxation ColeCole model with DC conductance was introduced to analyze the frequency-domain spectra of the ZnO varistor.The double relaxation Cole-Cole model was used to fit the frequency-domain spectra,which were measured at room temperature.It was found that there were a andβrelaxation processes with the activation energy about 0.68 and 0.34 e V,which related to the intergranular phase in Bi-rich microregions and the oxygen vacancy respectively.The intensity ofαrelaxation process increased with aging,whileβrelaxation process kept stable.A new y relaxation process with the activation energy about 0.73 eV was observed at the temperature about 393 K.The y relaxation process related to the interface states due to ZnO-ZnO homojunction,and as the impulse times increased,its activation energy and relaxation time decreased,but its relaxation intensity and shape parameter increased.With the increase of the impulse times,the DC conductivity increased obviously,and the activation energy dropped from 0.72 to 0.64 eV.Therefore,the aging status of ZnO varistor can be assessed comprehensively through activation energy of DC conductance,activation energy of y relaxation process,as well asσDC,△εα,△εγ,τγandγ,which are extracted from the modified multirelaxation Cole-Cole model.
作者
李春茂
陈子宣
杨雁
陈锡成
朱航
高波
吴广宁
LI Chunmao;CHEN Zixuan;YANG Yan;CHEN Xicheng;ZHU Hang;GAO Bo;WU Guangning(School of Electrical Engineering,Southwest Jiaotong University,Chengdu 610031,China)
出处
《高压电器》
CAS
CSCD
北大核心
2020年第2期85-92,共8页
High Voltage Apparatus
基金
国家杰出青年基金(51325704).
作者简介
李春茂(1963—),男,博士,教授,主要从事电工理论与新技术、电力电子系统电磁兼容及故障诊断等领域的研究。
