压敏陶瓷-硅橡胶复合材料的非线性压敏介电特性  

Nonlinear Dielectric and Conductivity Properties of ZnO Varistor/Silicone Rubber Polymer Composites

作　　者：谢竟成[1] 胡军[1] 何金良[1] 高雷[1] 郭志冲 

机构地区：[1]清华大学电机工程与应用电子技术系电力系统及发电设备控制和仿真国家重点实验室,北京100084

出　　处：《高电压技术》2015年第2期446-452,共7页High Voltage Engineering

基　　金：国家重点基础研究发展计划(973计划)(2014CB239500);国家自然科学基金(51007046)~~

摘　　要：开展兼具非线性电导和介电特性的复合材料的理论基础和应用研究,有助于更有效、广泛地解决高电压等级电力系统绝缘设备或部件电场分布不均匀的难题。为此,制备了ZnO压敏陶瓷-硅橡胶复合材料并测量了其非线性压敏介电特性。结果表明:制备的复合材料具有良好的分散性和非线性电导及介电特性;当ZnO压敏陶瓷填料体积分数>10%时,复合材料可以表现出明显的非线性介电特性,可以起到更显著的电场均匀作用;当ZnO压敏陶瓷填料体积分数>20%时,复合材料呈现出明显的非线性电导特性,电导非线性系数可以达到10以上,当电场强度超过压敏电压梯度时电导率可以提高100倍以上,而电场强度达到1.5倍压敏电压梯度时,可在对不均匀电场起抑制作用的同时,避免较大的损耗。Researches of the theories and application of polymer composites with both nonlinear conductivity and nonlinear permittivity are useful for dealing the nonuniform electrical fields widely existing in the insulation components of power systems. We fabricated ZnO/rubber composites and investigated their nonlinear dielectric and nonlinear conductivity properties. The results show that ZnO dispersed evenly in the obtained ZnO/rubber composites, and the composites showed nonlinear dielectric and nonlinear conductivity properties as expected. When the volume fraction of ZnO varistor is larger than 10%, the composites exhibit significant nonlinear dielectric properties, resulting in largely smoothed electrical fields. When the volume fraction of ZnO varistor is over 20%, the composites exhibit significant nonlinear conductivity properties, with a nonlinear coefficient over 10. In this case, when electric field exceeds the breakdown intensity（Eb）, the conductivity gets largely increased： it can be 100 times bigger than that under low field. Plus when electric field exceeds 1.5Eb, the composites can smooth the nonuniform electrical field without any obvious increase in dielectric loss.

关 键 词：ZNO压敏陶瓷 硅橡胶 复合材料 非线性电导特性 非线性介电特性 介质损耗 

分 类 号：TM21[一般工业技术—材料科学与工程]