极性反转电压下非线性电导硅橡胶复合材料电荷积聚特性

Charge Accumulation Characteristics of Nonlinear Conductive SIR Composites under Polarity Reversal Voltage

直流电缆附件是直流输电系统的薄弱环节,为研究非线性电导对极性反转电压下电缆附件硅橡胶绝缘电荷积聚特性的影响,通过添加SiC颗粒制备具有非线性电导的硅橡胶复合材料试样,利用三电极法和表面电位测量系统获得试样的电导率和表面电荷特性。实验结果表明:由于试样中SiC晶粒的晶格振动引起载流子晶格散射,高温会造成试样电导率降低;试样表面电荷平面分布特性表明,电晕电压极性反转后,平板试样内部残留的原极性电荷与表面的异极性电荷提高了局部电场强度,使试样的电导率升高,加速了表面电荷向试样内部迁移和异极性电荷中和过程,抑制了表面电荷的积聚。

The HVDC cable accessory is the weak point of the cable system.In order to study the effect of the nonlinear conductivity on the charge accumulation property of Si R cable accessory insulation under polarity reversal voltage,this paper prepared a Si R composites sample by mixing the Si C particle with the Si R matrix.The three-electrode method and the surface charge measurement system are applied to obtain the conductivity and surface charge properties.The result shows that the crystal lattice vibration in Si C causes the scattering of carriers,resulting in the decrease in conductivity of sample at high temperature.The surface charge properties of Si R composites sample under polarity reversal voltage indicate that the induced electric field between the surface charges and the heteropolar charges increases the conductivity of Si R composites after the polarity reversal of corona voltage,which accelerates the transfer of surface charge into the inside and the neutralization between heteropolar charges,subsequently suppressing the surface charge accumulation.