Study on Electrical Tree Suppression of SIR / EVA Blends under Temperature Gradient

SIR materials are widely used in insulation of high voltage cable accessories, and SIR electrical tree is the main cause of insulation failure. It is important to enhance the electrical tree suppression ability to maintain the safe and stable operation of power equipment.In this paper, the inhibition effect of SIRIEVA blends on the initiation and growth of electrical tree under temperature gradient was studied by electrical tree degradation experiment, which provided experimental basis and theoretical support for enhancing the suppression ability of SIR electrical tree. In this paper, SIRIEVA blends were prepared based on physical blending method, and the inhibition effect of SIRIEVA blends on the initiation and growth of electrical tree was studied under the condition of temperature gradient by scanning electron microscopy, infrared spectroscopy and tensile strength experiments. It is found that SIRIEVA blends can enhance the electrical tree suppression ability. This is consistent with the theoretical analysis results that physical cross-linking of SIR and EVA increases the threshold of molecular chain break, hindering the transport of thermal electrons to break the molecular chain and interface of SIR, thus leading to the enhancement of the inhibitory force of electrical tree.