一种适用于高温条件下的电声脉冲法空间电荷测量系统  

An Improved Pulsed Electro-acoustic Setup For Space Charge Measurement at High Temperatures

作　　者：宁鑫[1] 彭宗仁[2] 刘鹏[2] 张宏亮[2] 冯骅[2] 贾志杰[1] 曹永兴[1] 朱轲[1] 

机构地区：[1]国网四川省电力公司电力科学研究院,四川省成都市610072 [2]电力设备电气绝缘国家重点实验室(西安交通大学),陕西省西安市710049

出　　处：《中国电机工程学报》2017年第6期1835-1842,共8页Proceedings of the CSEE

基　　金：国家自然科学基金项目(51207123);国网四川省电力公司研究开发项目(521997140025)~~

摘　　要：温度变化时聚合物材料内部的电荷输运特性或电极/介质界面处电荷注入的特性可能发生改变。因此,研究聚合物绝缘材料在高温下的空间电荷特性十分必要。该文采用新型的、具有高居里点的聚偏氟乙烯–三氟乙烯(polyvinylidene fluoride-trifluoroethylene,P(VDF-TrFE))薄膜作为压电传感器,分体设计了脉冲耦合电路、信号放大器电路和电极加热单元,建立了适用于室温~110℃的电声脉冲法(pulsed electro-acoustic method,PEA)空间电荷测量系统。从电声脉冲法测量空间电荷的原理出发,分析了对压电传感器输出的电压信号、最终空间电荷密度值的影响因素。计入了温度对试样中的声速和试样相对介电常数的影响,得出了温度影响空间电荷密度的幅值和位置的校正方法。利用该系统测量了纯环氧试样在不同温度下的空间电荷分布特性。The temperature plays an important role on charge transport characteristics in dielectrics as well as charge injection behavior between electrodes and dielectrics; it is of great significance to study the space charge behaviors of polymeric insulation materials at high temperature. An improved pulsed electro-acoustic measurement system has been developed based on a new type piezoelectric transducer called polyvinylidene fluoride-trifiuoroethylene which has a high Curie point. The R-C couping circuit has been separated from the heating part to eliminate the damage caused by high temperature, and the signal amplifier as well. Factors which determine the transducer output voltage signal and final space charge density have been studied based on the principle of pulsed electro-acoustic method. The temperature dependence of sound velocity as well as relative permittivity has been measured; At last, correction of the temperature effect on the measurement system has been carried out. Effects of temperature on space charge distribution in pure epoxy resin have been investigated.

关 键 词：空间电荷 电声脉冲法 高温 压电传感器 校正 

分 类 号：TM85[电气工程—高电压与绝缘技术]