SiC/环氧复合涂层对绝缘子表面电荷消散特性的影响

Influence of SiC/epoxy Composite Coating on the Surface Charge Dissipation Characteristics of Insulators

  • 摘要: SiC/环氧非线性电导材料表面涂覆是抑制直流GIS内部气-固界面电荷积聚的有效方法。为了更加全面评估SiC/环氧复合涂层加速电荷消散的性能,采用指形电极(情形1)和针电极(情形2)两种电极结构在试样表面积聚不同的初始电荷分布,然后测试了绝缘子表面电荷随时间的动态变化特性,并分析了初始电荷分布模式对表面电荷的导消散途径的影响,在此基础上理清了SiC/环氧复合涂层加速电荷消散的机制。结果表明,情形1中表面电荷消散过程由“快速-慢速”两个阶段组成,沿面传导是其电荷主导消散途径;情形2中表面电荷消散过程则经历了“慢速-快速-慢速”三个阶段,气体侧带电粒子中和是其表面电荷主导消散方式。两种情形的电荷自建电场分布不同导致了电荷主导消散方式的差异,而SiC/环氧复合涂层则主要是改变表面陷阱和表面电导率来加速电荷消散。本文有助于掌握SiC/环氧复合涂层对绝缘子表面电荷消散特性的影响,为非线性电导涂层的性能评价提供借鉴。

     

    Abstract: The surface coating of SiC/epoxy nonlinear conductive materials is an effective method to suppress the charge accumulation at the gas-solid interface within DC GIS. In order to comprehensively evaluate the performance of SiC/epoxy composite coatings in accelerating charge dissipation, two electrode structures are employed, namely finger-shaped electrode(Case 1) and needle electrode(Case 2), to accumulate different initial charge distributions on the insulator sur-face. Subsequently, the dynamic distributions of surface charges over time are tested, and the influence of initial charge distribution patterns on the charge dissipation pathway is analyzed. Based on this, the mechanism of accelerating charge dissipation in SiC/epoxy composite coatings is elucidated. The results indicate that in Case 1, the surface charge dissipation process consists of two stages: "fast-slow, " with surface conduction being the dominant pathway for charge dissipation. In Case 2, the surface charge dissipation process undergoes three stages: "slow-fast-slow, " with gas-side charged particle neutralization being the dominant mode of surface charge dissipation. The difference in the self-built electric field distribution between the two cases results in variations in the dominant pathways of charge dissipation. Moreover, the SiC/epoxy composite coating primarily alters surface traps and surface conductivity to accelerate charge dissipation. This study contributes to understanding the influence of SiC/epoxy composite coatings on the charge dissipation characteristics on insulator surfaces, providing insights for the performance evaluation of nonlinear conductive coatings.

     

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