环氧复合绝缘材料表面电荷积聚与消散特性研究

为明确环氧复合绝缘材料表面电荷积聚与消散特性,搭建了一套空气中绝缘材料表面电位二维自动测量装置,采用有源静电探头法测量了直流充电后环氧复合绝缘表面电位分布。结果表明,绝缘表面主要积聚与外施电压极性相同的电荷,提高直流电压幅值会显著增加表面电荷密度。随直流电压施加时间的增加,表面电荷密度先快速增加,而后趋于饱和。当加压至闪络后,绝缘材料表面存在清晰的放电通道,绝缘表面仍然积聚大量的电荷,并关于闪络通道对称分布。表面电位消散分为表面电荷自发电场主导的消散阶段和电荷扩散主导的消散阶段。外施电压幅值越高,表面初始电荷密度越高,起始消散速度越快,消散到一定值需耗费更长的时间。

Research on Surface Charge Accumulation and Dissipation Characteristics of Epoxy Composite Surface

In order to clarify the surface charge accumulation and dissipation characteristics of epoxy composite insulating materials, a two-dimensional automatic measuring device for surface potential of insulating materials in air was built. The surface potential distribution of epoxy composite insulating materials after DC charging was measured by active electrostatic probe method. The results show that the charges with the same polarity as applied voltage are mainly accumulated on the insulating surface. Increasing the DC voltage amplitude will significantly increase the surface charge density. With the increase of DC voltage applied time, the surface charge density increases rapidly at first and then tends to be saturated. When pressure is applied to flashover, there is a clear discharge channel on the surface of insulating material, and a large amount of charge still accumulates on the insulating surface, and the distribution of flashover channel is symmetrical. Surface potential dissipation can be divided into two stages: the dominant dissipation stage of surface charge spontaneous electric field and the dominant dissipation stage of charge diffusion. The higher the applied voltage amplitude, the higher the initial charge density on the surface is, the faster the initial dissipation speed is, and it takes longer to dissipate to a certain value.