Pressure Dependence of XLPE/SiR Interfacial Breakdown Behavior

Cable accessories have an important connecting role in the cable system. The safe and stable operation of cable accessories depends on their good interface performance, and the interfacial electrical performance depends on pressure. The effect of pressure on the interfacial breakdown performance and breakdown damage is investigated by analyzing the breakdown voltage, carbonization degree and silicone rubber (SiR) precipitation products after cross-linked polyethylene (XLPE)/SiR interfacial breakdown in this article. First, XLPE/SiR interfacial breakdown experiments were performed at pressures of 0.1,0.15,0.2, and 0.25 MPa. Then, FTIR was used to study the characteristic products and content changes of silicone rubber materials after breakdown. And the carbonization depth of the breakdown was studied by scanning electron microscope (SEM), and finally the carbonization area of the breakdown was calculated based on the binarization method. The results manifest that increasing the pressure has a positive effect on improving interfacial breakdown voltage. The interfacial pressure significantly affects the damage of the interfacial material after breakdown. Increasing the interfacial pressure causes the breakdown process of the interface to gradually develop from the contact surface to the interior of the material. The amount of products precipitated due to breakdown of SiR gradually decreases as the increasing pressure, which is positively correlated with the carbonization area. The research has certain reference significance for the installation and operation of cable accessories.