固体电介质空间电荷与电流和电位的同步联合测量系统

Simultaneous measurement system for space charge,current and potential of solid dielectrics

为了综合、全面地获取固体电介质的介电响应信息,准确表征固体电介质的介电性能,提出了一种基于“分区同时”测量策略的空间电荷与电流以及空间电荷与开路电位的同步同时联合测量方案。该联合测量方案基于现有的电流测量单元、电位测量单元以及空间电荷测量单元,通过T型滤波器和阻交电感对测量单元进行合理组合,保证测量过程中各单元之间无互相干扰,从而实现电流、开路电位和空间电荷的同步联合测量。以碳化硅(SiC)掺杂的低密度聚乙烯(LDPE)试样的电流、电位和空间电荷同步联合测量结果为基础,对测量系统进行了校验。研究结果表明,电流测量基础噪声在pA数量级,在1~10 kV电压测量效果良好,空间电荷测量精度并未受到影响。联合测量方案在技术上简单易行,能够实现对固体电介质的电流、电位和空间电荷同步同时联合测量,同时该联合测量系统具有进一步扩展的空间,为后续多种测量技术的同步联合应用提供参考与基础。

In this article,a simultaneous measurement system of space charge and current as well as space charge and the potential in open circuit based on the“region division but at the same time”measurement strategy is proposed to obtain the dielectric response information comprehensively and to accurately characterize the dielectric properties of solid dielectrics.The simultaneous measurement system consists of the readymade current measurement unit,potential measurement unit and space charge measurement unit.Those measurement units are reasonably combined through a T-filter and an inductance to isolate alternating component to ensure that there is no mutual interference between each unit during the measurement process.In this way,the simultaneous measurement of the current,space charge and the potential in open circuit could be achieved.The measurement system is validated by the measurement results of the current,potential,and space charge of low-density polyethylene(LDPE)samples with silicon carbide(SiC)filler.Results show that the basic noise of current measurement is quantitative in pA,the voltage measurement is good in the range of 1~10 kV,and the accuracy of space charge measurement is not affected.The proposed simultaneous measurement system is simple and easy to achieve technically,which can realize simultaneous measurement of current,potential,and space charges of solid dielectrics.In addition,the combined simultaneous measurement system still has room for further expansion and provides reference and basis for combined simultaneous application of multiple measurement technologies.