正交电场下XLPE/SIR介质界面空间电荷特性  

Space Charge Properties at XLPE/SIR Interface Under Orthogonal Electric Stress

作　　者：张宇巍[1] 朱有玉 王霞[1] 吴锴[1] 傅明利 侯帅 

机构地区：[1]电力设备电气绝缘国家重点实验室(西安交通大学),西安710049 [2]南方电网科学研究院,广州510080

出　　处：《南方电网技术》2015年第10期52-56,共5页Southern Power System Technology

基　　金：国家自然科学基金(51377131);南方电网科技项目(K-KY2014-31)~~

摘　　要：直流电缆附件绝缘和电缆绝缘的界面同时承受着沿着电缆径向的体电场和沿电缆轴向的界面电场,这两个电场在方向上相互正交,在界面上的分布和集中使得复合绝缘界面的空间电荷特性变得复杂。采用交联聚乙烯(crosslinked polyethylene,XLPE)和硅橡胶(silicone rubber,SIR)制成双层试样模拟附件结构中的复合绝缘,通过界面贴覆铝箔针-板电极(针电极为正/负)、板-板电极三种电极形式为绝缘界面提供正交电场,运用电声脉冲法(pulse electro-acoustic,PEA)分别测量了体电场、正交电场作用下XLPE/SIR界面空间电荷的分布情况。结果表明,在体电场和界面电场的正交电场作用下,XLPE/SIR界面的空间电荷峰值出现明显变化:试样加压20 min后,界面贴覆针电极为负的针-板电极时,界面电荷峰值随施加电场强度的增加先增大后减小,使XLPE侧电极在较低场强下即发生注入;界面贴覆针电极为正的针-板电极时,界面电荷峰值在电场作用下减小,加剧了SIR侧的正电荷注入;在界面板-板电极作用下,界面电荷峰值变化不大,但仍有所下降。The interface of DC accessory insulation and cable insulation suffers both the bulk electric field along cable radial direction and the interfacial electric field along cable axial direction. The distribution and concentration of the two orthogonal electric fields make the interfacial space charge property complex. Aiming at the problem,the cross-linked polyethylene（ XLPE） and silicone rubber（ SIR） are used to compose a double layer sample to imitate the compound insulation of cable accessory,and the interfacial space charge at XLPE / SIR interface are measured by pulse electro-acoustic（ PEA） method under bulk electric field and three different orthogonal electric stresses,namely bulk electric field from electrodes of PEA and interfacial electric field provided by aluminum foil needle-plate electrodes（ the polarity of needle electrode is positive / negative） or plate-plate electrodes. Results showthat the XLPE /SIR interface space charge changes obviously under orthogonal electric stress（ both bulk and interface electric fields）. After twenty minutes’ applying of orthogonal electric stress,the interface charge increases first and then decreases with electric stress under the interfacial electric field from negative polarity need-plate electrodes,which leads to an injection of electrons to XLPE from negative electrode; interface charge decreases with electric stress under the interfacial electric field from positive polarity need-plate electrodes,which increases the injection of positive charge to SIR from positive electrode; under the interfacial electric field from plate-plate electrodes,the interfacial space charge decreases a little.

关 键 词：交联聚乙烯/硅橡胶 直流附件 正交电场 界面电荷 电声脉冲(PEA) 

分 类 号：TM211[一般工业技术—材料科学与工程]