The contact area between solid insulations, namely solid–solid interfaces, affect the dielectric characteristics of an entire insulation system. With the theoretical and experimental studies covered in this paper, we intend to investigate the effects of the elastic modulus, interface contact pressure, and surface smoothness/roughness on the tangential alternating current (AC) breakdown strength of contact surfaces at dielectric interfaces that undergo a tangential electric field. Four distinct solid dielectric specimens with various elastic modulus values were employed. The interfaces between the same materials were subjected to AC breakdown and partial discharge (PD) tests at different contact pressure values. In addition, the interface surfaces were polished using four different sandpapers of various grits to scrutinize the effect of surface roughness. A deterministic model built around the tribology of solid surfaces was proposed to determine the sizes of the interfacial cavities and to simulate the 3D displacement and deformation of the surface protrusions based on the surface roughness, contact pressure, elastic modulus, and hardness of an interface. The estimated sizes of cavities and contact areas were then coupled with a comprehensive breakdown model that addressed the cavity discharge and breakdown of contact areas, separately. Finally, the results by the model were correlated with the results of the AC breakdown and PD experiments to elucidate not only how cavities were linked at solid–solid interfaces but also the effects of roughness, elasticity, contact pressure, and gas pressure inside of the cavities.

固体绝缘之间的接触面积，即固​​体-固体界面，会影响整个绝缘系统的介电特性。通过本文所涵盖的理论和实验研究，我们打算研究弹性模量、界面接触压力和表面平滑度/粗糙度对介电界面处接触面的切向交流 (AC) 击穿强度的影响，这些界面经历了切向电场。使用了具有不同弹性模量值的四种不同的固体介电样品。相同材料之间的界面在不同的接触压力值下进行交流击穿和局部放电（PD）测试。此外，使用四种不同粒度的砂纸对界面表面进行抛光，以检查表面粗糙度的影响。提出了一种围绕固体表面摩擦学建立的确定性模型，以确定界面腔的大小，并根据界面的表面粗糙度、接触压力、弹性模量和硬度来模拟表面突起的 3D 位移和变形。然后将空腔和接触区域的估计尺寸与综合击穿模型相结合，分别解决空腔放电和接触区域的击穿问题。最后，该模型的结果与 AC 击穿和 PD 实验的结果相关联，以阐明空腔在固体-固体界面处的连接方式，以及粗糙度、弹性、