Relationship Between Porosity and Dielectric Constant and Tensile Strength of Insulating Paper

It is found that when the structural properties of insulating paper are changed, its electrical properties also change significantly, but the mechanism is not clear, which makes us unable to choose the best structural parameters. Therefore, this paper starts from the porosity structure parameter to explore its influence on the dielectric constant and tensile strength of insulating paper. The results show that with the increase of the porosity of the insulating paper, the fiber content in the insulating paper decreases, so the dielectric constant and tensile strength decrease. In addition, the smaller the average pore size of the insulation paper and the smaller the matrix density of the fiber, the smaller the dielectric constant will be even the porosity is close; The higher the matrix density of insulation paper is, the higher the tensile strength is.

I. Introduction

The power system in the operation of the essential need for power transfer and transformation, in this process, the transformer plays an extremely important role, its operation reliability and safety will directly affect the operation safety and reliability of the whole power system. As an excellent insulating material, the properties and structure of insulating paper are closely related to the mechanical and electrical properties, which determine the quality and performance of transformer to a certain extent. The quality and performance of insulating paper are largely affected by the types of raw materials, pulping process, manufacturing process, use process and environment. According to statistics, transformer insulation accidents in operation account for about 50% of all transformer accidents [1]. The internal insulation of oil immersed transformer mostly uses transformer oil with insulating paper, and the deterioration of oil paper insulation performance is the main cause of transformer insulation accidents [2], so the electrical performance of insulating paper directly affects the insulation level and stable operation ability of oil immersed transformer.