不同老化程度XLPE/SIR复合绝缘的电荷输运特性  

Charge transport characteristics of XLPE/SIR composite insulation under different ageing degree

作　　者：王雅妮 齐寅山 王玉宁 李煜晨 杨兴武 刘春 WANG Yani;QI Yinshan;WANG Yuning;LI Yuchen;YANG Xingwu;LIU Chun(College of Electrical Engineering,Shanghai University of Electric Power,Shanghai 200090,China)

机构地区：[1]上海电力大学电气工程学院,上海200090

出　　处：《绝缘材料》2024年第8期52-60,共9页Insulating Materials

基　　金：国家自然科学基金资助项目(52207025)。

摘　　要：交联聚乙烯(XLPE)与硅橡胶(SIR)是目前常用的高压直流电缆本体绝缘与附件增强绝缘材料,二者构成的复合绝缘在长期热应力作用下会发生老化。为探究不同老化程度XLPE/SIR复合绝缘的电荷输运特性,本研究制备了不同老化程度的XLPE/SIR试样,对其进行空间电荷与等温松弛电流联合测量。同时结合傅里叶红外光谱(FTIR)测试与量子化学计算(QCC),构建了老化前后XLPE/SIR体系的能带模型,基于此对XLPE/SIR的电荷输运行为进行探讨。结果表明:XLPE/SIR中间界面始终积聚负电荷,且电荷量随老化时间延长而增多。阴极与阳极附近始终存在同极性电荷积聚,且分布范围随老化时间延长而减小。材料发生老化后,SIR中的电荷陷阱深度变化不大,而XLPE中出现了更深的电荷陷阱。未老化XLPE/SIR中间界面处的负电荷积聚主要由Maxwell-Wagner极化导致,而老化后试样界面负电荷积聚增多主要与SIR中引入了电子浅陷阱以及XLPE中引入了电子深陷阱有关。Cross-linked polyethylene(XLPE)and silicone rubber(SIR)are commonly used insulation materials for highvoltage direct current cables and reinforced insulation materials for accessories at present.The composite insulation composed of the two will age under long-term thermal stress.To investigate the charge transport characteristics of XLPE/SIR composite insulation with different ageing degrees,XLPE/SIR samples with different ageing degrees were prepared and subjected to simultaneous measurement of space charge and isothermal relaxation current.At the same time,by combining Fourier transform infrared spectroscopy(FTIR)testing and quantum chemical computation(QCC),an energy band model of XLPE/SIR system before and after ageing was constructed,and the charge transport behavior of XLPE/SIR was explored.The results show that negative charges always accumulate at the XLPE/SIR interface,and the amount of charge increases with ageing time.There are always homopolar charges accumulating near the cathode and anode,and the distribution range decreases with ageing time.After ageing,the depth of charge traps in SIR does not change much,while deeper charge traps appear in XLPE.The negative charge accumulation at the interface between the unaged XLPE/SIR is mainly caused by Maxwell-Wagner polarization,while the increase of negative charge accumulation at the interface of the aged samples is mainly related to the introduction of shallow electron traps in SIR and deep electron traps in XLPE.

关 键 词：复合绝缘 热老化 电荷输运 量子化学计算 能带模型 

分 类 号：TM215[一般工业技术—材料科学与工程]